VOLUMEN 68 BROJ 2/19¾a-Obuća-br-2-2019-1.2.pdf · Tradicionalne metode determiniranja morfologĳe stopala u svojem opsegu uzimanja mjera nisu dovoljne da točno definiraju oblik

VOLUMEN 68 BROJ 2/19

12

20

25

30

34

38

Časopis za kožu, obuću, dizajn te srodnapodručja u interdisciplinarnom pristupuThe Journal for leather, footwear, design, as well asother similar areas in an interdisciplinary approach

Izdavač i vlasnik / Publisher and owner:Hrvatsko društvo kožara i obućara, Prilaz barunaFilipovića 28a, HR - 10000 Zagreb, www.hdko.hr

Croatian Leather and Footwear Society, Prilazbaruna Filipovića 28a, HR - 10 000 Zagreb,www.hdko.hrGalavni i odgovorni urednik / Editor-in chief:Budimir MĳovićUrednica / Editor:Antoneta TomljenovićPredsjednik HDKO-a:Jadranka AkalovićUredništvo / Editorial board:Yi Li, UKXuangai Wang, AustraliaUwe Reischl, USARavinda S. Goonetilleke, Hong KongLubos Hes, Czech RepublicMariana Ursache, RomaniaSenhorinha Teixeira, PortugalTonghua Zhang, ChinaJelena Balent, CroatiaZenun Skenderi, CroatiaDarko Ujević, CroatiaBranka Vojnović, CroatiaSnježana Firšt Rogale, CroatiaSlavenka Petrak, CroatiaAndrea Pavetić, CroatiaAnica Hursa Šajatović, CroatiaSanja Ercegović Ražić, CroatiaMartinia Ira Glogar, CroatiaGoran Čubrić, CroatiaAlica Grilec, CroatiaEmilĳa Zdraveva, CroatiaSuzana Kutnjak Mravlinčić, CroatiaSuzana Mihanović, CroatiaMarin Sovar, CroatiaFranka Žuvela Bošnjak, CroatiaVladan Končar, CroatiaLektorica / Lector:Antonia TreseljOblikovanje i prĳelom / Technical editor:,H1 design, vl. Dražen StopićDinamika izlaženja / Publishing dynamic:4 broja godišnje u 400 primjeraka / 4 issues peryear in 400 copies

4 Prilagođeni uložak, dio 1: beskontaktna metoda otkrivanjaantropometrĳskih točaka na stopalu

Insole customized Part 1: Non-contact Method ofAnthropometric points Detection for Feet

Primjena 3D skenera u funkcĳi digitalne antropometrĳestopala (FootSABA 3D Foot Scanner)

3D scanner application in the function of digital footantropometry (FootSABA 3D Foot Scanner)

Automobilske navlake od prirodne kože – svojstva iproblematika šivanja

Natural leather car upholstery – characteristics andsewing challenges

Obilježena 140. godišnjica tekstilne stručne škole

Glavni i odgovorni urednik

Budimir Mĳović

RĲEČ UREDNIKA

Dragi čitatelji,

u ovom broju informirat ćemo vas o tri zanimljiva rada kojasmo pripremili te o ostalim novostima iz našeg područja. Bezobzira na ciljeve studĳe, bilo da je rĳeč o morfološkoj klasifikacĳistopala ili prilagođavanju proizvoda poput ortopedskih potplata iliprikladne obuće za atipična stopala, neophodno je pronaćiracionalnu metodu za otkrivanje antropometrĳskih točaka i oblina.Rad dr. sc. Maneesha Kumara Mishre i suradnika implementirabeskontaktnu metodu mjerenja gdje mjerenje skeniranog stopalamože predstaviti adaptivni model stopala koji se možeupotrebljavati u izradi bilo koje vrste stopala. Ta metoda predlažerazličite tehnike praćenja s pomoću različitih podesivih ravnina. U3D grafičkom procesu, morfološke krivulje su lokalizirane spomoću tih antropometrĳskih točaka i olakšavaju identifikacĳustopala tim mjerenjima.

Svrha istraživanja dr. sc. Sarajka Bakse i suradnika jestznanstveno utvrditi primjenu automatizirane 3D digitalizacĳeprostorne antropometrĳske izmjere stopala u odnosu premaučestalosti pogrešno odabrane obuće na temelju tradicionalnihmetoda izmjere i odabira. Tradicionalne metode determiniranja morfologĳe stopala u svojem opsegu uzimanjamjera nisu dovoljne da točno definiraju oblik i veličinu, za razliku od suvremenog pristupa uporabe 3D skenerai digitalnih metoda izmjera 3D virtualnih modela, koji mogu iznimno precizno i brzo personalizirati veliki brojantropometrĳskih podataka morfologĳe stopala.

Prirodna koža specifičan je prirodni materĳal koji daje dozu luksuza autosjedalima i interĳeruautomobila. Njezina dugotrajnost, cĳena i manja tržišna ponuda dovode do manje primjene za autonavlake, uodnosu prema tekstilnim materĳalima, ali je zato iznimno poželjna. Prema dosadašnjim istraživanjima krojenjei šivanje kožnih autonavlaka zahtĳeva veću pozornost i pri odabiru odgovarajuće kože, šivaćeg stroja, konca,igle i tipa šivanog šava, koji će dati zadovoljavajuća svojstva autonavlaci u svim njezinim segmentima. RadBeti Rogine Car i suradnika pridonosi stručnim saznanjima i specifičnostima koja su vezana za prirodnu kožu,njezinoj namjeni za autosjedala te odgovarajućoj kvaliteti šivanog šava.

Jelena Balent priredila je obilježavanje 140. godišnjice tekstilne stručne škole.

Živjeli!

Prilagođeni uložak, dio 1: beskontaktna metoda otkrivanjaantropometrĳskih točaka na stopalu

Maneesh Kumar Mishra1, 2, 3, Pascal Bruniaux1, 2, 3, Guillaume Tartare1, 2, 3 and ChristineCampagne1, 2, 3

1 University of Lille Nord de France, Lille, France2 Ecole Nationale Supérieure des Arts et Industries Textiles, Roubaix, France3GEMTEX, Roubaix, France

E-mail: [email protected], [email protected]

SažetakBez obzira na ciljeve studĳe, bilo da se radi o morfološkoj klasifikacĳi stopala ili prilagođavanju proizvoda poput ortopedskih uložaka / potplata ili prikladneobuće za atipična stopala, neophodno je pronaći racionalnu metodu za otkrivanje antropometrĳskih točaka i krivulja. Studĳe o objašnjenju antropometrĳestopala su malobrojne, a u nekim slučajevima predstavljaju suprotnosti mjerenjima između ručnog postupka i postupka automatskog skeniranja. Također,naš cilj bio je upotrĳebiti beskontaktnu metodu mjerenja da se otkrĳu antropometrĳske točke na stopalu. U ovoj metodi se predlažu različite tehnike praćenjapomoću različitih podesivih ravnina. U 3D grafičkom procesu, morfološke krivulje su lokalizirane pomoću tih antropometrĳskih točaka i omogućujuidentifikacĳu stopala tim mjerenjima. Ona su uspoređena s mjerenjima pomoću 3D skenera stopala da bi se metoda otkrivanja antropometrĳskih točakamogla potvrditi i poboljšati metoda koju koriste ovi skeneri.

Ključne rĳeči3D grafički proces, 3D model uloška, morfologĳa stopala, antropometrĳa stopala, prilagođeni uložak.

1. UvodBudući da je ljudsko tĳelo kompleksna struktura, može se

podĳeliti na 5 dĳelova: glavu, vrat, trup, dvĳe ruke čĳi završetak su šake idvĳe noge čĳi završetak su stopala. Svaki organ ima svoju jedinstvenufunkcĳu. Na primjer, stopala nose težinu tĳela u stojećem položaju teomogućuju hodanje i trčanje. Budući da su ti zadaci vrlo kompleksni,anatomĳa stopala je također vrlo kompleksna. Jedno stopalo se sastoji od42 mišića, 26 kostĳu, 33 zgloba i barem 50 ligamenata i tetiva izgrađenih odčvrstog vlaknastog tkiva koje povezuje sve pokretne dĳelove kao i 250 000znojnih žlĳezda. Ovo čudo evolucĳe može podupirati stotine tona kojepredstavljaju našu težinu u kretanju svaki dan. Bezbrojni dĳelovi stopalarade skladno kako bismo došli s jednog na drugo mjesto. Međutim,opterećenje i ograničenja kretanja izlažu ih većem riziku ozljeda nego drugedĳelove tĳela, a rizici ovise o našoj ukupnoj anatomĳi. Zato je važnopoznavati različite patologĳe stopala kako bi se unaprĳed izbjegavale ili seposlĳe lĳečile. Naravno, antropometrĳsko poznavanje stopala i različitimjerni alati su potrebni za dĳagnozu podĳatra kod dizajna cipele koja gaštiti ili koja pomaže kod lĳečenja izvjesnih patologĳa. Mnoge od ovih bolestivećinom zahtĳevaju da se dizajniraju specifične cipele ili ulošci. Ovisno otomu je li potrebno ili nĳe personalizirati proizvode, potrebno je morfološkoi dimenzionalno poznavanje pacĳenta ili populacĳe što se postižemjerenjima.

Mnogi problemi stopala, uključujući „čekićast“ (svinut) nožni prst,žuljeve, izbočenje palčanog zgloba na stopalu (čukalj), kukuruz i žulj,koštanu izraslinu na peti, prste kao kandže, urasle nokte na nogama,gljivice na nožnim noktima, atletsko stopalo, mogu nastati zbog nemara,nepristalih cipela i jednostavno zbog iznošenosti cipela. Stopala takođermogu pokazivati da je tĳelo ugroženo ozbiljnom bolešću. Na primjer,kostobolja će prvo napasti zglobove stopala.

Ako je drugi, treći ili četvrti nožni prst prekrižen, savĳen u sredininožnog zgloba ili je usmjeren pod čudnim kutom, to se može nazvati

„čekićastim“ (svinutim) nožnim prstom. „Čekićasti“ nožni prsti često nastajuzbog nepristalih cipela. Žene su sklonĳe bolovima koji se povezani satakvim prstima nego muškarci zbog različite modne obuće. Budući da mišićisvakog nožnog prsta rade u parovima, pa kada su nožni mišići izvanravnoteže, može se stvoriti „čekićasti“ prst [1], [2]. Zbog ovog disbalansamišića, tetive i zglobovi nožnih prstĳu dolaze pod pritisak, a on prisiljavanožni prst u oblik glave čekića. Opasnosti za čekićaste prste uključuju:ravna stopala, visoki svod, artritis, ozljede nožnog prsta, starenje. Za osobes dĳabetesom ili slabom cirkulacĳom krvi, čekićasti prsti mogu predstavljatiozbiljan problem jer imaju veći rizik od infekcĳa i čireva na stopalu [3].

Izbočenje palčanog zgloba na stopalu (čukalj) je iskrivljen velikinožni palac (hallux valgus) koji izviruje izvan osnove prsta što prisiljavaveliki palac da se uvine. Čukalj može biti bolan kada se stisne u cipeli, akod mnogih osoba preuske cipele su uzrok stvaranja čuklja [4], [5]. Stručniradovi navode da osobe s hallux valgus deformacĳom imaju manju debljinui poprečni presjek kratkih mišića aduktora (primicača) i fleksora(pregibača) palca u usporedbi s osobama bez hallux valgus deformacĳe [6].Općenito, ova deformacĳa ima različite uzroke, uključujući prirođenedeformacĳe, artritis, traumu i nasljednost. Sugeriralo se da su suatrofiraniili slabi mišići pregibači (fleksori) povezani sa stvaranjem deformacĳanožnih prstĳu. Međutim, ne postoji dovoljno dokaza za ovakvu teorĳu.Visoke pete (one prisiljavaju prste u prednji dio cipele), nepristale cipele(pretĳesne, preuske ili prešiljaste su podložne za stvaranje čukalja) mogupovećati vjerojatnost ove deformacĳe [8]. Zato ojačavanje unutarnjihmišića nožnih prstĳu može pomoći smanjiti incidencĳu i ozbiljnostdeformacĳa stopala starĳih osoba [9]. Cipele i ulošci trebaju biti u skladu soblikom stopala korisnika tako da ne stišću i pritišću bilo koji dio stopala[10].

Petni trn (Plantarni fascitis) se prihvaća kao sinonim upaleplantarne fascĳe. Sufiks „itis“ upućuje na upalno oboljenje. Uobičajeno je dalĳečnici brkaju između petnog kalcifikata i plantarne fascĳe kad ih pacĳentposjeti zbog boli u peti. Sam petni kalcifikat nĳe bolan; to je upala i iritacĳaizazivana plantarnom fascĳom koja može boljeti. Petni kalcifikati se često

4

Izvorni znanstveni radUDK: [572.087:611.986]:004.925.84

vide na rendgenskim snimkama pacĳenata koji nemaju bol u peti iliplantarnu fascĳu [13]. Skoro 10% ozljeda nastaje naročito kod sportaša čĳeaktivnosti uključuju mnogo trčanja i skakanja [14].

U osnovi postoje dvĳe vrste svodova stopala: uzdužni svodovi(sastoje se od medĳalnih i lateralnih dĳelova – razdjeljuje težinu tĳela ipritisak u različitim smjerovima zajedno s poprečnim svodovima) i poprečnisvodovi [15]. Prema istraživanju Subotnicka 60% populacĳe ima normalnesvodove, 20% ima visoki svod (cavus) i 20% ima ravno (spušteno) stopalo(planus) [16]. Ako su uzdužni svodovi viši nego je normalno, naziva sevisoki svod [17][18]. Ima otisak s ili bez uske spojnice koja spaja prednji dionoge i područje pete. Koštana struktura na bočnoj strani (previšesupinirano) stopala znači veći rizik ozljede zbog manjeg područja zanošenje težine i time se prenosi veće opterećenje na stopalo i nogu. Visokisvod (pes cavus) često nastaje zbog neurološkog sindroma i drugihmedicinskih uvjeta kao npr. : cerebralne paralize, Charcot-Marie-Tooth(CMT) bolesti, spine bifide, polia (poliomĳelitisa, dječje paralize), mišićnedistrofije ili moždanog udara.

Kada su uzdužni svodovi spušteni, stopalo je spušteno ili ravno(planus) [19], [20]. Spušteno stopalo kao i kavusno stopalo (s visokimsvodom) ne prenosi sile učinkovito i zato može uzrokovati bol u stopalu.Štoviše, to također dugoročno utječe na razdiobu pritiska u druge dĳelovetĳela što može uzrokovati bolove u leđima. Ova metamorfoza je rezultatveće inverzĳe stražnjeg dĳela stopala koja je nastala udarca pete u grupikoja ima spušteno stopalo [21].

Birtane i sur. ocĳenili su učinak različitih kategorĳa pretilosti navrĳednosti plantarnog tlaka [22]. Ova studĳa je uključivala stopala (lĳevo idesno stopalo) 50 ispitanika podĳeljenih u dvĳe grupe kao nepretila i pretilagrupa 1 prema njihovim vrĳednostima indeksa tjelesne mase. Istraženezone tlaka su: vršni tlak falange, vršni tlak medĳalnog dĳela prednjegstopala, vršni tlak srednjeg dĳela stopala, vršni tlak bočnog dĳela stopala,vršni tlak srednjeg dĳela stopala, vršni tlak stražnjeg dĳela stopala,plantarno kontaktno područje.

Veal i sur. kvantificirali su povećanje težine [23]. Za tu svrhuautori su provjerili je li povećanje težine utjecalo na srednje vršne tlakovestopala tako što su kontrolirali funkcĳu stopala, deformacĳu i strukturu. Novisustav za dinamičko mjerenje tlaka u cipeli (Pedar sustav) upotrĳebljen jeza mjerenje vršnih plantarnih tlakova stopala.

U ovom dĳelu predstavljaju se glavne bolesti i patologĳe stopala.Patološke procjene pokazuju da su poznavanje i morfološka analiza istokao i antropometrĳa odlučujući faktori u dĳagnozi podĳatra.

2. Morfološka analizaMorfološka analiza je područje koje se odnosi na proporcĳe i

dimenzĳe antropometrĳskih mjera. Poznavanje morfologĳe je značajno namnogim područjima jer može objasniti npr. je li se time mogu objasnitiusponi i padovi fikološkog zdravlja osobe. Isticanje antropometrĳe imavažnu ulogu u forenzičkim istraživanjima za identifikacĳu žrtve što se tičespola, populacĳske grupe i demografije [24].

U obućarskoj industrĳi antropometrĳa je značajni preduvjet zaoptimiranje kalupa cipele i uložaka prema različitim dobnim grupama,rasama, sastavu tĳela i spolu. Mnogi radovi se bave s problemomoptimizacĳe i povezani su s mjerenjima. Za mjerenje stopala postojinekoliko osnovnih metoda na tržištu kao što su pomična mjerila, crteži,mjerne vrpce itd. Međutim, današnji postupci kao 3D skeneri stopala čini seda su prikladnĳi. Ortopedičari možda najviše upotrebljavaju gipsani odljevza dobivanje 3D oblika stopala jer je pogodan za upotrebu i konkurentanpo cĳeni. Međutim, 3D skener bi se bolje prilagodio zbog dostupne cĳene iupotrebe u stvaranju baze podataka o klĳentima ili za kampanje mjerenja.

Čini nam se da je prioritet analizirati antropometrĳu 3D stopala,dobiti najmodernĳa različita sredstva mjerenja stopala i verificirati ilidefinirati njihovu međusobnu povezanost.

2.1. Antropometrĳa stopalaPo definicĳi antropometrĳa je tehnika mjerenja ljudskog tĳela i

njegovih različitih dĳelova. Mjerenje ljudskog tĳela je čvrsto povezano srazličitim mjernim točkama definiranim na kostima [25]. Na sl. 2 opisuju se

različite kosti stopala tako što se crvenom i zelenom bojom pokazujuantropometrĳske točke.

Na kompletnom ljudskom tĳelu različite ravnine (sagitalna,prednja, poprečna) dĳele tĳelo kako bi se pripremio mjerni proces [26] štonĳe slučaj za stopala. U radovima Witane i sur. [27] antropometrĳske točkesu jedine referencĳe mjerenja koje su korištene za klasifikacĳu 18 dimenzĳapo kategorĳama prema dužini između dvĳe točke i ravnine, širine izmeđudvĳe točke, kontura opsega smještenim s obzirom na jednu, dvĳe i li tritočke: dužina stopala, dužina svoda, peta prema unutarnjem gležnju, petaprema vanjskom gležnju, peta prema petom prstu, širina stopala, širinapete, bimaleolarna širina, širina srednjeg dĳela stopala, visina unutarnjeggležnja, visina vanjskog gležnja, visina na 50% dužine stopala, opsegglavice, opseg gornjeg dĳela stopala (rista), opseg dugačke pete, opsegkratke pete, opseg gležnja, opseg struka.

Zbog usporedbe dimenzĳa stopala između dva spola i također sodgovarajućim podacima drugih populacĳa, Hajaghazadeh i sur. su dodalidruge dimenzĳe [28]. Dodane su dužine drugog, trećeg i četvrtog nožnogprsta koji su izmjereni u smjeru Brannockove osi tako da se dobĳe 21dimenzĳa.

Slika 1: Različite kosti stopala, antropometrĳske točke

2.2. Tehnike mjerenja stopalaIzrada udobne obuće temelji se na antropometrĳskom

istraživanju koje određuje morfološki karakter stopala, ponašanje sustavastopalo-obuća i rezultatima morfofunkcionalne optimizacĳe oblikaproizvoda. Prirodne anatomsko morfološke konstrukcĳe stopala, njegovokorektno statičko i dinamičko funkcioniranje se osigurava racionalnimunutarnjim oblikom cipele, oblikom koji se određuje konstrukcĳom kalupacipele. Konstrukcĳa kalupa, određivanje dimenzĳa koje su potrebne da seispune zahtjevi udobnosti većeg dĳela potrošača uz minimalne proizvodnetroškove mora se temeljiti na poznavanju i najpreciznĳoj karakterizacĳianatomskih morfoloških razlika tipova stopala koji se susreću unutarpopulacĳe korisnika i učestalosti ovih tipova unutar populacĳe. Zbog togaje potrebno periodično provoditi antropometrĳske studĳe populacĳe premaodređenim kriterĳima (spolu, dobi, geografskoj regĳi itd.) kako bi se dobilipodaci o dimenzĳskim posebnostima prosječnog reprezentativnog stopalaza tu populacĳu, kao i zakoni razdiobe antropometrĳskih parametara kojikarakteriziraju reprezentativno prosječno stopalo populacĳe dotične zemlje[29].

Najuobičajenĳi pristupi uključuju upotrebu digitalnih pomičnihmjerila za direktna mjerenja i 3D skeniranja te analizu otiska stopala zaindirektna mjerenja. Vrlo je važno osigurati adekvatnu obuku tehničara dabi se korektno pozicionirale oznake na odgovarajućim anatomskihtočkama.

Glavni cilj uzimanja mjera stopala je dobiti aproksimacĳu većinepreciznih dimenzĳa stopala i zato biti u mogućnosti dizajnirati kalup cipelekoji je fizička potpora bitna za dizajn cipele.

5

Tradicionalne mjerne metode kao npr. otisak stopala tintom,digitalno pomično mjerilo i Brannockov uređaj su tradicionalni manualnipristupi koji se koriste za prikupljanje dimenzĳa stopala. Međutim, ljudskagreška može utjecati na preciznost mjerenja digitalnim pomičnim mjerilom.Različiti tehničari mogu dobiti nedosljedne i proturječne rezultate mjerenja.Vrlo je važno provesti adekvatnu obuku tehničara da korektno određujuoznake na odgovarajućim anatomskim točkama [30]. Također, da se dobĳupouzdane mjerne veličine, važno je poštivati pravila na snazi i norme [31].Druga sredstva za tradicionalno mjerenje služe za mjerenje dužinekorektno orĳentiranog stopala, strateških kutova, opsega antropometrĳskihkontura koji su korektno identificirani s obzirom na antropometrĳske točke,te otisak stopala drugim tehnikama.

Digitalno pomično mjerilo (katkada se pogrešno naziva digitalnoVernier mjerilo) je precizan instrument koji se može upotrebljavati za vrloprecizno mjerenje internih i eksternih udaljenosti. McPoil i sur. koristili sudigitalno pomično mjerilo za mjerenje i kombinacĳu nekolikoantropometrĳskih mjerenja da bi predvidjeli plantarnu površinu [32]. Šestmjernih veličina koje su uspoređene kod proučavanja su: ukupna dužinastopala, dužina glavice, dorzalna visina svoda, širina prednjeg dĳelastopala, širina srednjeg dĳela stopala, širina pete.

Brannockov uređaj, konstruiran 1927., je uređaj za mjerenjestopala koji je bio obvezan u svim prodavaonicama obuće na malo. Budućida se njime ručno rukuje, te zbog preciznosti mjerenja, kvalitetnekonstrukcĳe i jednostavnog, a ipak potpuno funkcionalnog dizajna, razlogsu zašto su Brannockovi mjerni uređaji postali standard u obućarskojindustrĳi [27]. Premda se ovaj mjerni uređaj smatra najpouzdanĳim zamjerenje dužina stopala s obzirom na savršeno poravnavanje sBrannockovom osi, neki autori i dalje upotrebljavaju tradicionalnu mjernuvrpcu za svoja mjerenja [33] [34]. Ove tehnike nisu zadovoljavajuće zadobivanje mjernih veličina koje bi se mogle upotrebljavati za atipičnemorfologĳe.

3D digitalno mjerenje se obično provodi pomoću 3D skenera kojimože biti različit ovisno o željenoj visini mjerenja . Tvrtka BFTS HumanTechnology nudi 2 verzĳe INFOOT 3D skenera [35]. Prva verzĳa možemjeriti visinu od 150 mm, a druga verzĳa 250 mm. Ova druga verzĳa jezanimljiva za područje čizama gdje je potrebno dublje poznavanje gornjegdĳela stopala ili u području ortoze. 3D skener stopala koristi tehnologĳuskeniranja optičkim laserom. INFOOT skenira oblik stopala od anatomskihtočaka i automatski mjeri gotovo 20 mjernih objekata.

Witana i sur. pokazuju veliko zanimanje za upotrebu 3D skenerastopala. Autori su uspoređivali u svojem proučavanju mjerne rezultate 3Dskenera s ručnim mjerenjima stopala. U radu se ističe da važne razlike utočnosti mjerenja nastaju zbog mjernih alata, protokola mjerenja, vremenamjerenja, te stupnja uvježbanosti mjeritelja [27]. Lee i sur. su dobili sličnerezultate kod usporedbe s konvencionalnim metodama mjerenja stopala, alinaročito kod upotrebe digitalnog pomičnog mjerila, otiska stopala tintom, tedigitalnog otiska stopala [30]. 3D skener je bio neizostavan alat zavrednovanje rezultata antropometrĳskih parametara koji su dobiveni 3Dmjerenjima i njihovom statističkom i matematičkom obradom u radovimaPantazia i sur. [29]. 3D skener stopala su koristili i Nacher i sur. zapreciznost i brzinu da bi klasificirali stopala populacĳe od 316 ispitanica.Ova studĳa predstavlja interes za poboljšanje udobnosti cipela pomoćumodela kojim se predviđa pristalost obuće na temelju korisničkih podataka[36].

Podĳatri upotrebljavaju druge tehnike da bi direktno dobili 3Doblik donje strane stopala sa ciljem dizajna ortopedskih uložaka koji suprilagođeni pacĳentu. Na primjer, može se navesti okvir s dvostrukimotiskom [37] koji omogućuje da se od otiska stopala realizira 3D oblik dvajustopala u gipsu ili smoli i da se konačno dobĳu ortopedski ulošci. Ovaj ručnipostupak nĳe direktan i skup je jer zahtĳeva potrošni materĳal zaoblikovanje i izradu uloška. Postupak bi se mogao odvĳati numerički i bržeu CD-u.

Ručno mjerenje općenito uzrokuje i mjerenje grešaka ovisno omjeritelju i njegovom zamoru ako ga provodi na mnogo osoba. Da bi seizbjegao takav problem, u industrĳi su razvĳeni različiti tipovi 3D skenerastopala. Međutim, protokol mjerenja i iskorištavanje rezultata ovih novihalata za mjerenje stopala mogu utjecati na preciznost mjerenja. Zato seovaj rad posvećuje primjeni naše vlastite metode mjerenja temeljene na 3D

neobrađenim rezultatima skenera. Ovi rezultati će se usporediti srezultatima koji su dobiveni direktno od softvera kojeg je prodao proizvođačizabranog skenera. Potrebna je antropometrĳska analiza jer predstavljasredište procesa mjerenja.

3. Antropometrĳska analiza mjernihveličina stopala3.1. Antropometrĳske točke

Mjerenja stopala u biti ovise o antropometrĳskim točkama kojesu definirane na preciznim mjestima kostura. Uređaj za ručno mjerenjestopala, koji se koristi i znanstveno je provjeren, je uređaj koji je izumioBrannock. Pozicioniranje stopala u ovom uređaju omogućuje definiratireferentnu os za mjerenje: Brannockovu os. Općenito, za stopalo kojenema problem deformacĳe (tipična deformacĳa: naznačuje bolesti)referentna os je virtualna linĳa između pterniona prema vrhu drugog nožnogprsta (A). Budući da mogu postojati male razlike između mjerenja rukompomoću mjerne vrpce, Brannockovog uređaja i 3D skenera, čini se važnimpodsjetiti se na to zašto su antropometrĳske točke važne za mjerenjestopala i kako se trebaju uzimati te mjere ili interpretirati kako bi sepronašao najbolji kompromis između ovih različitih metoda. Danas serazlikuje 19 antropometrĳskih točaka:

1) Pternion :2) Metatarzalna tibĳa : Najviše medĳalno istaknuta točka na prvojmetatarzalnoj kosti bone3) Unutarnji gležanj : Najviše medĳalna točka unutranjeg gležnja4) Vanjski gležanj : Najviše lateralna točka vanjskog gležnja5n) n-ti prst : n-ti vrh prsta6) Rist: Vrh točke rista7) Metatarzalna fibula : Najviše lateralno istaknuta točka na petojmetatarzalnoj kosti8) Najviša točka prvog metatarzala : Vrh točke opsega glavice9) Sfirion :10) Sfirionska fibula :11) Točka dočeka : Točka stražnjeg dĳela pete12) Spojna točka :13 & 13’) točke kalkaneusa : Najviše medajlno i lateralno istaknute točke napetnoj kosti14) Navikularna kost :15) Peti metatarzal : Tuberoznost 5. metatarzala16) Prvi zglob prsta : Najviša točka prvog zgloba prsta17) Peti zglob prsta : Najviša točka petog zgloba prsta18) Prvi metatarzal : Najviša točka glavice prvog metatarzala19) Najviša točka srednjeg dĳela stopala : Najviše točka vertikalnog opsegana 50% dužine stopala od pterniona

Na sl. 2 prikazan je položaj ovih točaka u odnosu na kosturstopala i zglobova. Naravno, u praksi će se ove točke pozicionirati s malimpomakom kojeg uzrokuje višak mišićne mase koja okružuje strukturu kosti.

6

Slika 2: Anatomske kosti, antropometrĳske točke

3.2. Mjerne veličine stopalaMjerne veličine stopala se općenito svrstavaju u 4 kategorĳe

(dužine, visine, širine i opsezi). Peta kategorĳa (kutovi) koja je potrebna zadizajn obuće (taban, cipela) se dobĳe iz prethodnih mjernih veličina.

Dužine: Sve udaljenosti se mjere duž Brannockove osi (X-smjer)L1 – dužina stopala: udaljenost od točke 1 do vrha najdužeg prstaL2 – dužina svoda: udaljenost od točke 1 do točke 2L3 – peta do unutarnjeg gležnja: dužina od točke 1 do točke 3L4 – peta do vanjskog gležnja: dužina od točke 1 do točke 4L5 – peta do petog prsta: udaljenost od točke 1 do točke 5L6 – peta do sfiriona: udaljenost od točke 1 do točke 9L7 – peta do sfirionske fibule: udaljenost od točke 1 do točke 10Visine: Sve udaljenosti se mjere u vertikalnom smjeru (Z-smjeru)H1 – Visina unutarnjeg gležnja: udaljenost od poda do točke 3H2 – Visina vanjskog gležnja: udaljenost od poda do točke 4H3 – Visina rista: udaljenost od poda do točke 6H4 – Visina sfiriona: udaljenost od poda do točke 9H5 – Visina sfirionske fibule: udaljenost od poda do točke 10H6 – Visina srednjeg dĳela stopala: maksimalna visina izmjerena s linĳomna 50% dužine stopala od točke 1Širine: Sve udaljenosti se mjere u smjeru okomitom na Brannockovu os (Y-smjer)Kod ovog tipa mjerenja mogu nastajati greške jer u ručnom načinu radaupotrebom cefalometra ili nekim 3D skenerima ove udaljenosti mogu bitinajkraće udaljenosti između mjernih točaka.W1 – Širina stopala: udaljenost od točke 2 do točke 7W2 – Bimaleolarna širina: udaljenost od točke 3 do točke 4W3 – Širina srednjeg dĳela stopala: maksimalna širina izmjerena s linĳomkod 50% dužine stopala od točke 1W4 – Širina pete: udaljenost od točke 13 do točke 13᾿

Opsezi: Ova vrsta mjerenja može predstavljati konturu nacrtanu u obliku(ex. skener ili CAD) ili ekvivalentnu konturu koja predstavlja istegnutumjernu vrpcu.G1 – Opseg glavice: opseg od stopala koji prolazi kroz točku 2, točku 8 itočku 7G2 – Opseg rista: najmanji opseg koji prolazi kroz točku 6G3 – Dugački opseg pete: opseg koji prolazi kroz točku 6 i točku 11G4 – Kratki opseg pete: minimalni opseg koji prolazi kroz točku 12 i točku11G5 – Opseg gležnja: vodoravni opseg koji prolazi kroz točku 12G6 – 50% opsega dužine stopala: okomit opseg kod 50% dužine stopala odtočke 1Kutovi: Kut prema bočnoj linĳi stopalaA1 – Kut prvog prsta: kut s planom BA2 – Kut petog prsta: kut s planom C

3.3. Protokol mjerenja 3D skenerom stopalaPrva kampanja mjerenja provedena je tako da se počela stvarati

dovoljna baza podataka da se potvrdi naš 3D grafički proces. Skenirana sustopala 100 osoba. Nĳe se razlikovalo između stopa muškaraca i žena. Naovom stupnju istraživanja morfologĳa stopala ne ovisi o spolu. Razlikovanjeće se izvršiti kasnĳe kod izrade obuće prema ciljanoj populacĳi.

Mjerni uređaj koji je korišten za skeniranje različitih stopala zanašu bazu podataka je skener stopala INFOOT. Dizajner je odredioprotokol mjerenja. U prvoj fazi 8 malih komada materĳala je zalĳepljeno nastopalo osobe kako bi se izvršilo skeniranje tako da softver može izmjeritiveličinu ukupnog volumena stopala (sl. 3).

Taktilna analiza kostĳu stopala se provodi da se bolje otkrĳusljedeće antropometrĳske točke: metatarzalna fibula 7, sfirionska fibula 10,vanjski gležanj 4, rist 6, metatarzalna tibĳa 2, navikularna kost 14, sfirion 9,te unutarnji gležanj 3 (sl. 3).

Pet crvenih naljepnica lokalizira referentne točke za izračunrazličitih antropometrĳskih točaka i pozicioniranje morfoloških kontura.Antropometrĳski izvještaji gdje korisnik može intervenirati doprinoseautomatskom procesu računanja i umjeravanju (kalibracĳi) po potrebi. Naslici 4 prikazani su rezultati morfologĳe koji će se ispitati.

Slika 3: Oznake za proces skeniranja

Sllika 4: Otkrivanje antropometrĳskih točaka i morfološke krivulje nastvarnom stopalu

Na sl. 5 prikazani su rezultati mjerenja (dužine, širine, visine,kutovi i opsezi) provedeni u normalnim uvjetima upotrebe skenera, tj.stopala se moraju pozicionirati između dvĳe zelene linĳe.

7

Slika 5: Skeniranje i mjerne veličine stopala

4. 3D grafički procesU ovom poglavlju govori se o primjeni nove metode

antropometrĳe stopala. To je vrlo je precizna metoda koja se možeprimjenjivati, čak prilagoditi, svakom stopalu jer je poluautomatska, tj.preporučljiva s parametrima koji su specifični za morfologĳu pacĳenta iliklĳenta. Svaka faza se mora strogo slĳediti s obzirom na antropometrĳskepovezanosti koje su integrirane u proces.

4.1. Kontura otiska stopalaPrva faza 3D grafičkog procesa je da se stopalo uklĳešti u

trapezoid koji se sastoji od 6 ravnina za definicĳu geometrĳe optimalnekonture koja obuhvaća otisak stopala. Za tu svrhu koriste se dvĳe tehnikečĳa je svrha pronaći kontaktno područje ili područja između površineokomite na tlo i 3D oblika stopala.

Budući da se radi ručno kod mjerenja stopala, bitno je da se prvouklĳešti peta na vertikalnoj površini A kako bi se definirala nula koordinatnogsistema duž X osi, čime se omogućuje otkriti kontaktnu zonu koja dajeaproksimacĳu položaja točke 1, što se naziva 1᾿ (sl.2 i sl. 6a). Zatim se moratranslatirati i okrenuti stopalo tako da se nalazi na vertikalnoj ravnini -Bprema ravnini -A što daje dvĳe kontaktne zone. U našem procesu postupakje obratan jer je stopalo učvršćeno u apsolutnom koordinatnom sistemuR0(O,x,y) (sl. 6a). Potrebno je tražiti ravninu -B prĳe ravnine -A. Zato sedizajnira pomični koordinatni sistem R1(O1,x,y) u odnosu na R0 i kontrolirase s dvĳe translacĳe duž X i Y osi i rotacĳom duž Z osi. Dva pravcaporavnata na X i Y osima u R1 koji podupire dvĳe ravnine moći će setranslatirati i rotirati tako da se područja mogu vizualizirati pomoću svojihpridruženih ravnina.

Na isti način ravnina -C se pozicionira pomoću pomičnogkoordinatnog sistema R2(O2,x,y) (sl. 6b). Ovaj koordinatni sistem je izrađenu odnosu na R1 i kontrolira se translacĳom duž Y osi i rotacĳom duž Z osi.Pravac poravnat na X osi u R2 koji podupire ravninu će se translatirati irotirati tako da može vizualizirati dvĳe zone pomoću svoje pridruženeravnine.

Ravnina -D omogućuje traženje kuta nagiba prvog prsta koji sepozicionira pomoću pomičnog koordinatnog sistema R3(O3,x,y) čĳeishodište O3 klizi translacĳom na pravcu koji predstavlja Y os u R1 (sl. 7a).Koordinatni sistem R3 se vrti oko svoje Z osi da se upravlja kutom nagibanjegove X osi na kojoj se poravnava pravac koji podupire ravninuotkrivanja kontaktne zone sa stopalom.

Slika 6: Uklještenje pete pomoću dvĳe ravnine, pronalaženje medĳalnih ilateralnih kontaktnih točaka

Slika 7: Pronalaženje medĳalnih i lateralnih kontaktnih točaka nožnihprstĳu

Ravnina -E traži kut nagiba petog prsta (sl. 7b). Pozicionira sepomoću pomičnog koordinatnog sistema R4(O4,x,y) čĳe ishodište O4 klizitranslacĳom na pravcu koji predstavlja Y os u R1. Koordinatni sistem R4 vrtise oko svoje Z osi da upravlja kutom nagiba svoje X osi na kojoj seporavnava pravac koji podupire ravninu pronalaženja.

Na ovom mjestu u procesu zahtĳeva se locirati Brannockovu os.U prvoj fazi određuje se srednja os između dvĳe ravnine B i C da sepronađe sjecište B1 između ove osi i pravca povezanog s ravninom- A (sl.8a). Ova točka je polazište B1 Brannockove osi jer predstavlja projekcĳuzbog antropometrĳske točke 1 (prilagodba točke 1᾿).

Drugi kraj je na kraju drugog nožnog prsta (sl. 8b). Pronalaženjeovog kraja postiže se izradom pomičnog koordinatnog sistema R5(O5,x,y)čĳe ishodište O5 klizi translacĳom na pravcu koji predstavlja X os u R1.Referentni R5 okreće se oko svoje Z osi zbog upravljanja kutom nagiba osiY na kojoj se poravnava pravac koji podupire pronalaženje ravnine F2. Ovajkut mora se podešavati tako da ravnina F2 bude okomita na Brannockovuos. Kada se pronađe krajnja točka 52, ona se projicira na desnu stranu kojapredstavlja Y os ove točke za dobivanje drugog kraja B2 na Brannockovojosi. Ova os se tada može crtati od B1. Zatim, na točki B1 se izrađuje novikoordinatni sistem R6(O,x,y) koji je okomit na Brannockovu os (sl. 8a).Ravnina pronalaženja A᾿ se izrađuje od pravca koji predstavlja X os u R6da bi se prilagodio krajnji položaj točke 1. Uvjet je da točka 1 mora biti naistoj visini kao i u području koje je pronađeno pomoću A᾿.

Slika 8:

Sad se može finalizirati kontura otiska stopala izradom zadnje F1 ravninekoja pronalazi kraj 51 prvog prsta (sl. 9a). Ova ravnina se poravnava napravcu koji predstavlja Y os koordinatnog sistema R7(O7,x,y) čĳe ishodištese translatira na Brannockovoj osi. Na sl. 9b prikazana je kontura koja jepronađena i na kojoj se mogu locirati antropometrĳske točke.

Slika 9: Pronalaženje kontaktne točke 51, kontura otiska stopala

4.2. Pronalaženje antropometrĳskih točakai mjerenjeVrhovi prstĳu (51, 52, 53, 54, 55)

Kod iste analitičke analize kao i za prvi nožni prst različitikoordinatni sistemi R8(O8,x,y) R9(O9,x,y) R10(O10,x,y) postavljeni su dužBrannockove osi da se dobĳu različiti pravci koji predstavljaju Y os svakogkoordinatnog sistema (sl. 10a). Zatim su izrađene ravnine pronalaženja F3,F4, F5 na svakom pravcu (sl. 10b). 3 krajnje točke 53, 54, 55 zadnjih prstĳukoje su pronađenje pomoću ovih ravnina se tada projiciraju naBrannockovu os. Dužina svakog prsta s obzirom na B1 (projicirano iz 1)može se mjeriti direktno na X osi koordinatnih sistema za 51, 52, 53, 54, 55.

8

Slika 10: pronalaženje kontaktnih točaka 53, 54, 55

Spojna točka (12) i točka dočeka (11)

Spojna točka se definira iz kosih ravnina, ravnina G u kosomsmjeru od vrha stopala (bočni pogled), ravnina H u smjeru kontaktne zonedonjeg dĳela tibĳe (bočni pogled) (sl. 11a). Ove dvĳe ravnine okomite naravninu B nastaju iz dva pravca, jedan od njih je orĳentiran duž X osikoordinatnog sistema R11(O11,x,y), drugi je orĳentiran duž Y osikoordinatnog sistema R12(O12,x,y) (sl. 11c). Ovi koordinatni sistemi rotirajuoko Y osi u R1 u XY ravnini za R1 da bi se u obzir uzimala okomitost.Orĳentacĳa ovih koordinatnih sistema i njihov međusoban položaj sobzirom na referentni R1 omogućuju upravljati dodirnim zonama ravnina ukontaktu sa stopalom.

Zatim se izrađuje koordinatni sistem R13(O13,x,y) na sjecištudva pravca koji definiraju kontaktne ravnine G, H. Ovaj koordinatni sistemaima Y os poravnatu s X osi u R11. Zatim se izrađuje valjak i centrira u O13,s time da je njegova glavna os poravnata na Z osi u R13 (sl. 11b). Z os uR13 također se nalazi na sjecištu dvĳe ravnine G i H. Modifikacĳompromjera ovog valjka moguće je pronaći kontaktnu zonu pete kojapredstavlja točku dočeka stopala 11.

Od pravca koji povezuje ishodišnu točku O13 u R13 i točkedočeka 11 koja je pozicionirana i usmjerena na točku 11 nastaje koordinatnisistem rezanja R14(O14,x,y) (sl. 11c). Žuta krivulja koja nastaje iz rezanjastopala pomoću ravnine rezanja u R14 predstavlja kratki opseg pete G4.Spojna točka 12 je na krajnjoj točki ove krivulje u vertikalnom smjeru premagore.

Slika 11: Smjer kontaktnih točaka 11, 12

Točka na ristu (6)

Točka na ristu 6 je točka koje se pronalazi ravninom G. Nalazi sena donjem dĳelu kontaktne zone (sl. 12a). Ova točka je jedna od tri točkeprolaza kroz krivulju opsega rista G2. Druga točka Ars se nalazi na gornjemdĳelu svoda (sl. 12a). Sjecište između ravnine B1 paralelno s B i stopalaomogućuje da se izradi dio krivulje koji simbolizira oblik unutarnjeg svoda.Treća točka Bmid se definira u sredini dvĳe točke Bmax, Bmin koje se nalazena krajevima tangentnih područja ravnine C. Ove točke se definiraju napravcu izrade ravnine G (sl. 12a). Budući da točka Bmid ne pripada površinistopala, potrebno je izraditi točku rezanja R15(O15,x,y) na 6 da se izradikrivulja G2. Krivulja G᾿2 je krivulja okomita na Brannockovu os kojapredstavlja opseg rista G᾿2 koji predlaže skener stopala.

Slika 12: Pronalaženje kontaktne točke 6

Metatarzalna tibĳa (2), metatarzalna fibula (7), najviša točka prvogmetatarzala (8)

Točka 2 metatarzalne tibĳe i točka 7 metatarzalne fibule mogu sepronaći iz kontura otiska stopala (sl. 13b). Zato su uzeta u obzir sjecištaizmeđu pravaca izrade ravnina B i D kao i ravnine C i E na donjoj razini, tj.

tlu. Ove dvĳe točke su dovoljne za izradu osi spajanja stopala. Na krajuove osi izrađuje se koordinatni sistem R16(O16,x,y) tako da je njegova X osna ovoj osi spajanja (sl. 13a). Opseg glavice G1 se dobĳe pomoću XYravnine rezanja koja se može orĳentirati duž X osi u R16 da se pronađenajviša točka prvog metatarzala 8 (sl. 13c). Metatarzal tibĳe 2 i metatarzalfibule 7 predstavljaju ekstremne točke na krivulji G1 u X i -X smjerovima(prema vanjskoj strani stopala). Krivulja G᾿1 je krivulja okomita na tloporavnato s osi spajanja koja predstavlja opseg glavice G᾿2 kojeg predlaže3D skener stopala.

Slika 13: Pronalaženje kontaktnih točaka 2, 7, 8, 19

Najviša točka srednjeg dĳela stopala (19)

Krivulja koja predstavlja opseg na 50% dužine stopala odpterniona dobĳe se iz koordinatnog sistema rezanja R17(O17,x,y) koji jesmješten duž Brannockove osi pomoću iste metode koja je korištena zaR8, R9 i R10 (sl. 13b). Na toj krivulji se G6 otkriva na najvišoj točki srednjegdĳela stopala 19 koja predstavlja ekstremnu točku u smjeru –Y (sl. 13c).

Medial malleolus (3), lateral malleolus (4) (unutarnji gležanj (3), vanjskigležanj (4)

Unutarnji gležanj 3 i vanjski gležanj 4 dobĳu se iz dvĳe ravnine B’,C’ paralelne na ravnine B i C. Za drugu točku u obzir je uzeta drugakontaktna zona koja je nadređena prvoj (sl. 14ab)

Slika 14: Pronalaženje kontaktnih točaka 3, 4

Sfirion (9), sfirionska fibula (10)

Za pronalaženje sfiriona 9 i sfirionske fibule 10 koristi se tehnikaekvivalentna za točke 3 i 4. Dvĳe ravnine za pronalaženje B᾿᾿ i C᾿᾿ kreću semalo dublje u stopalu da se okruži gležanj. Na toj točki moguće je izraditidvĳe krivulje koje okružuju svaki gležanj kod traženja sjecišta između ovedvĳe ravnine i stopala. Sfirion 9 i sfirionska fibula se tada nalaze na njihovojnajdonjoj točki što predstavlja ekstremnu točku u –Z.

Slika 14: Pronalaženje kontaktnih točaka 3, 4

4.3. Analiza procesa mjerenjaIz antropometrĳskih točaka i morfoloških krivulja koje su

pronađene i izrađene pomoću 3D grafičkog procesa izračunate su mjerneveličine potrebne za dimenzioniranje stopala (tab. 1: L1 do G6). Tablica 1:Mjerenje razlike između 3D grafičkog mjerenja i mjerenja skeniranjemuspoređuje rezultate dobivene preporučenom metodom i metodom kojomse koristi skener. Budući da skener omogućuje druga komplementarnamjerenja (mjerne veličine u kurzivu) u odnosu na standardne mjere(terminologĳa specifična za skener), to je dodano u popis (L8 do A1) takoda je usporedba potpuna.

9

3D grafičkomjerenje

Mjerenjeskeniranjem

Greška(%)

L1 – stopalo 277,5 280,6 1,1L2 – svod 200,6 203,4 1,3L3 – peta prema unutarnjemgležnju 68,1L4 – peta prema vanjskom gležnju 41,3L5 – peta prema petom nožnomprstu 229,6L6 – peta prema sfirionu 63,2L7 – peta prema sfirionskoj fibuli 50,1H1 – unutarnji gležanj 92,0H2 – vanjski gležanj 79,2H3 – rist 77,9 75,9 2,6H4 – sfirion 65,5 67,8 3,3H5 – sfirionska fibula 63,4 78,3 21,7H6 – srednji dio stopala 75,2W1 – stopalo 110,6W2 – bimaleolar 70,8W3 – srednji dio stopala 95,2W4 – peta 68,1 67,2 1,3G1 – glavica 276,9(277,5) 278,7 0,6G2 – rist 273,0(267,7) 282,7 3,4G3 – dugačka peta 372,0G4 – kratka peta 353,2G5 – gležanj 272,3G6 – 50% dužina stopala 266,7L8 – fibularni rist 166,6 175,7 5,1H7 – svod ili navikular 29,9 38,6 22,5H8 – vrh prvog metatarzala 26,4 (53,2) 47,6 44,5 (11,7)W5 – širina stopala 115,9 115 0,7A1 – prvi prst 5˚ -8,4˚ 159A1 – peti prst 21,4˚ 4,9˚ 336

Rezultati pokazuju da sva mjerenja korisna za određivanjeveličine stopala imaju samo malu pogrešku. Samo mjerna veličina H5 imagrešku uglavnom zbog mjerenja skeniranjem. Budući da to ovisi opozicioniranju komada materĳala koji je zalĳepljen na stopalo osobe zbogskeniranja da se odredi položaj sfirionske fibule, nepreciznost nastajezbog ovog ručnog načina rada. Isti problem je ustanovljen i za H7 (komadimaterĳala pozicionirani ručno).

Budući da skener ne mjeri G kako je navedeno u znanstvenojbibliografiji (sada G᾿ za skener), točka 8 je postala točka 8᾿ za skener čimese objašnjava razlika za H8. Ova razlika se mnogo smanjuje ako se vršimjerenje kako to prakticira skener (mjerenje između zagrada za 3D grafičkiproces).

Mjerenje dva kuta se može kritizirati kod primjene skenera. Ovomjerenje, koje je vrlo važno za definiranje osnovnog oblika uloška, ovisi okonturi otiska stopala.

Tehnika mjerenja našeg procesa temelji se na 3D obliku stopaladok je tehnika koju koristi skener različita i temelji se na pravcu od stopalašto često daje negativne kutove.

Tablica 1: Mjerenje razlike između 3D grafičkog mjerenja i mjerenjaskeniranjem

5. ZaključakU ovom radu razvĳen je 3D grafički proces za otkrivanje

antropometrĳskih točaka na stopalu. Ove antropometrĳske točke su bitneza dobivanje mjernih veličina koje karakteriziraju oblik i dimenzĳe stopala.Kod ovog beskontaktnog postupka mjerenja predlaže se tehnika praćenjakod koje se koriste virtualne podesive ravnine.

Usporedba je izvršena pomoću industrĳskih podataka mjerenja izspecifičnog softvera u 3D skener stopala. Ukupno gledavši, rezultatipokazuju dobro podudaranje između podataka izmjerenih 3D skenerom inašeg procesa. Međutim, industrĳske metode se kritiziraju jer ovise opozicioniranju oznaka na stopalu i antropometrĳskim omjerima koji suintegrirani u proces mjerenja. Time se objašnjava nekoliko razlika kod nekihmjernih veličina. Među ostalim, upotreba antropometrĳskih izvještaja je

nepoželjna i može uzrokovati mnogo više grešaka ako je stopalo koje semjeri izvan uobičajenog izgleda, tj. ima značajne deformacĳe. Naša metodaima prednost da se prilagodi ovom problemu jer se može testirati na stopalusa čukljem ili čekićastim prstom koji su pronađeni tĳekom kampanjemjerenja i u drugim

6. References

[1] Centre Hospitalier, “Le pied,” Bois de l’abbaye. .[2] J. A. DeBello, K. I. DeCoteau, and E. Beatty, “Taking A Novel Approach

To Hammertoe Surgery,” Podiatry Today, 2006. .[3] E. B. Neves, A. J. Almeida, C. Rosa, J. Vilaca-Alves, V. M. Reis, and

R. Mendes, “Anthropometric profile and diabetic foot risk: a cross-sectional study using thermography,” pp. 1–3, 2016.

[4] S. K. van de Velde, M. Cashin, R. Johari, R. Blackshaw, A. Khot, andH. K. Graham, “Symptomatic hallux valgus and dorsal bunion inadolescents with cerebral palsy: clinical and biomechanical factors,”Dev. Med. Child Neurol., vol. 60, no. 6, pp. 624–628, 2018.

[5] “Hallux valgus: only the handicap leads to the operation of the onion -Why Doctor,” Pourquoidoctteur.fr, 2016. [Online]. Available:https://www.pourquoidocteur.fr/MaladiesPkoidoc/1126-Hallux-valgus-seul-le-handicap-conduit-a-l-operation-de-l-oignon. [Accessed: 19-Jun-2019].

[6] S. Taş and A. Çetin, “Mechanical properties and morphologic featuresof intrinsic foot muscles and plantar fascia in individuals with halluxvalgus,” Acta Orthop. Traumatol. Turc., no. xxxx, pp. 3–7, 2019.

[7] J. Ragland, “How to get rid of bunions,” Getridofthings. .[8] R. O. N. B. Killian, G. S. Nishimoto, and J. C. Page, “Fo and an,” vol.

88, no. 8, pp. 365–374, 1998.[9] A. Paiva de Castro, J. R. Rebelatto, and T. R. Aurichio, “The

relationship between foot pain, anthropometric variables and footwearamong older people,” Appl. Ergon., vol. 41, no. 1, pp. 93–97, 2010.

[10] K. J. Mickle and C. J. Nester, “Morphology of the Toe Flexor Musclesin Older Adults With Toe Deformities,” Arthritis Care Res., vol. 70, no.6, pp. 902–907, 2018.

[11] A. Ladhani, “What are heel spurs?,” step-by-step foot care, 2015.[Online]. Available: https://stepbystepfootcare.com/blog/what-are-heel-spurs/. [Accessed: 21-Jun-2019].

[12] U. Chundru, A. Liebeskind, F. Seidelmann, J. Fogel, P. Franklin, andJ. Beltran, “Plantar fasciitis and calcaneal spur formation areassociated with abductor digiti minimi atrophy on MRI of the foot,”Skeletal Radiol., vol. 37, no. 6, pp. 505–510, Jun. 2008.

[13] H. Lemont, K. M. Ammirati, and N. Usen, “Plantar fasciitis: adegenerative process (fasciosis) without inflammation.,” J. Am.Podiatr. Med. Assoc., vol. 93, no. 3, pp. 234–7, 2003.

[14] L. Özgönenel, “Plantar Fasciitis,” Tech. Foot Ankle Surg., vol. 12, no.2, p. 109, 2013.

[15] J. D.B., Hollinshead’s Functional Anatomy of the Limbs and Back.Elsevier Health Sciences, 2008.

[16] T. F. Novacheck, “Review Paper The biomechanics of running,” GaitPosture, vol. 7, pp. 77–95, 1998.

[17] “Foot pain | Mast Cells & Collagen Behaving Badly.” .[18] J. G. Atwater, “Cavus Foot (High-Arched Foot) Video | Orthopedic

Doctor in Vero Beach, Florida.” .[19] G. Gijon-Nogueron, J. Montes-Alguacil, P. Alfageme-Garcia, J. A.

Cervera-Marin, J. M. Morales-Asencio, and A. Martinez-Nova,“Establishing normative foot posture index values for the paediatricpopulation: a cross-sectional study,” J. Foot Ankle Res., vol. 9, no. 1,p. 24, Dec. 2016.

[20] D. Carmody, P. Bubra, G. Keighley, and S. Rateesh, “Posterior tibialtendon dysfunction: An overlooked cause of foot deformity,” J. Fam.Med. Prim. Care, vol. 4, no. 1, p. 26, 2015.

[21] D. S. Williams, I. S. McClay, J. Hamill, and T. S. Buchanan, “Lowerextremity kinematic and kinetic differences in runners with high andlow arches,” J. Appl. Biomech., vol. 17, no. 2, pp. 153–163, 2001.

[22] M. Birtane and H. Tuna, “The evaluation of plantar pressure

10

distribution in obese and non-obese adults,” Clin. Biomech., vol. 19,no. 10, pp. 1055–1059, 2004.

[23] S. A. Vela, L. A. Lavery, D. G. Armstrong, and A. A. Anaim, “Theeffect of increased weight on peak pressures: Implications forobesity and diabetic foot pathology,” J. Foot Ankle Surg., vol. 37, no.5, pp. 416–420, 1998.

[24] M. Voracek, M. L. Fisher, B. Rupp, D. Lucas, and D. M. T. Fessler,“Sex Differences in Relative Foot Length and PerceivedAttractiveness of Female Feet: Relationships among Anthropometry,Physique, and Preference Ratings. Perceptual and Motor Skills,”2007.

[25] Printerest, “Ankle anatomy.” .[26] A. Cichocka, P. Bruniaux, and I. Frydrych, “3D Garment Modelling -

Creation of a virtual mannequin of the human body,” Fibres Text.East. Eur., vol. 22, no. 6, pp. 123–131, 2014.

[27] C. P. Witana, S. Xiong, J. Zhao, and R. S. Goonetilleke, “Footmeasurements from three-dimensional scans: A comparison andevaluation of different methods,” Int. J. Ind. Ergon., vol. 36, no. 9, pp.789–807, 2006.

[28] M. Hajaghazadeh, R. Emamgholizadeh Minaei, T. Allahyari, and H.Khalkhali, “Anthropometric Dimensions of Foot in Northwestern Iranand Comparison with Other Populations,” Heal. Scope, vol. 7, no. 3,2018.

[29] M. Pantazi, A. M. Vasilescu, A. Mihai, and D. Gurau, “Statistical-mathematical processing of anthropometric foot parameters andestablishing simple and multiple correlations. Part 1: statisticalanalysis of foot size parameters,” Leather Footwear J., vol. 17, no. 4,pp. 199–208, Dec. 2017.

[30] Y.-C. C. Lee, G. Lin, and M.-J. J. J. Wang, “Comparing 3D footscanning with conventional measurement methods.,” J. Foot AnkleRes., vol. 7, no. 1, p. 44, 2014.

[31] D. Webb, D. V. Bernardo, and T. Hermenegildo, “Evaluating andImproving Footprint Measurement : Orientation and Lengths,”Anthropologie, pp. 277–287, 2006.

[32] T. G. McPoil, B. Vicenzino, M. W. Cornwall, and N. Collins, “Can footanthropometric measurements predict dynamic plantar surfacecontact area?,” J. Foot Ankle Res., vol. 2, no. 1, 2009.

[33] O. Vrdoljak, M. K. Tiljak, and M. Čimić, “Anthropometricmeasurements of foot length and shape in children 2 to 7 years ofage,” Period. Biol., vol. 119, no. 2, pp. 125–129, 2017.

[34] K. Hasanzadeh and K. Salehzadeh, “The Relationship betweenAnthropometric Indices in Children and their Kinetic Performances ofAgility , Balance and Foot Power The Relationship betweenAnthropometric Indices in Children and their Kinetic Performances ofAgility , Balance and Foot Power,” no. May 2015, 2016.

[35] “BFTS GmbH.” .[36] B. Nácher et al., “A footwear fit classification model based on

anthropometric data,” SAE Tech. Pap., vol. 1, no. May 2014, 2006.[37] “Boite ŕ empreintes double - Salembier Pédicurie Podologie.” .

11

12

Insole customized Part 1: Non-contact Method of Anthropometricpoints Detection for Feet

Maneesh Kumar Mishra1, 2, 3, Pascal Bruniaux1, 2, 3, Guillaume Tartare1, 2, 3 and ChristineCampagne1, 2, 3

1 University of Lille Nord de France, Lille, France2 Ecole Nationale Supérieure des Arts et Industries Textiles, Roubaix, France3GEMTEX, Roubaix, France

E-mail: [email protected], [email protected]

AbstractRegardless of the objectives of the study, whether it is the morphological classification of the feet or the customization of products such as orthopedic insolesor appropriate footwear for atypical feet, it is the imperative to find a rational method for detecting the anthropometric points and curves. The studiesexplaining the anthropometry of the foot are very few and in some cases present contradictions in the measurements between the manual and automaticscanning processes. In addition, our goal was to implement a non-contact measurement method to detect the anthropometric points of feet. This methodproposes different tracking techniques using different adjustable planes. In a 3D graphical process, the morphological curves have been located with thehelp of these anthropometrics points and allowed the identification of the foot by their measurements. These measurements were compared with thoseobtained by a 3D foot scanner to validate the detection method of anthropometric points and improve it by employing these scanners.

Keywords3D graphical process, 3D insole model, foot morphology, foot anthropometry, customized insole.

1. IntroductionAs a complex structure, the human body can be divided into five

parts: the head, the neck, the torso, two arms extended by hands and twolegs extended by feet. Every organ has its own unique function. Forexample, the feet carry the weight of the body in standing position and allowwalking and running.

Foot anatomy is very complex, matching the complexity of thetasks it needs to perform. One foot is composed of 42 muscles, 26 bones,33 joints, and at least 50 ligaments and tendons made of strong fibroustissue to keep all the moving parts together, as well as 250,000 sweatglands. This evolution wonder is able to support hundreds of tons,representing our weight in motion each day. The innumerable parts of thefoot work in harmony to bring us from one place to another. However, thestress and the constraints of movements expose them to a greater risk ofinjury than other body parts, depending on our overall anatomy. It istherefore important to know the different pathologies of feet to avoid them apriori or treat them a posteriori. Of course, an anthropometric knowledge ofthe foot and various tools of measurement are necessary for the diagnosisof a podiatrist, the design of the shoe which protects it or which contributesto the treatment of certain pathologies. Many of these diseases stand incorrelation with the design of particular shoes or insoles. Regardless ofwhether there is a need for personalization of the products, the knowledgeof the morphology and foot dimensions should be spread throughmeasurement campaigns.

Many foot problems, including hammertoes, blisters, bunions,corns and calluses, heel spurs, claw and mallet toes, ingrown toenails,toenail fungus and athlete’s foot, can develop due to neglect, ill-fitting shoesor and simply tear and wear. Feet can also indicate if the body is underthreat from a serious disease. Gout, for instance, will attack the foot jointsfirst.

A hammertoe is a condition in which the second, third, or fourthtoe is crossed, bent in the middle of the toe joint, or just pointing at an oddangle. Hammertoes are often caused by ill-fitting shoes. Women are moreprone to suffer pain associated with hammertoes than men because ofdifferent kinds of fancy footwear and shoe gear. Since the muscles of eachtoe work in pairs, when the toe muscles get out of balance, a hammertoecan form [1][2]. Due to this muscle imbalance, the toe's tendons and jointssuffer a lot of pressure which forces the toe into a hammerhead shape.Hammertoe hazards include flat feet, high arch, genetic causes, arthritis,toe injury and aging. Hammertoes can become a serious problem forpeople with diabetes or poor blood circulation, as they are under a higherrisk of infections and foot ulcers [3].

A bunion is a crooked big-toe joint (hallux valgus) that protrudesat the base of the toe, forcing the big toe to turn inwards. A bunion can bepainful when confined in a shoe, and for many people, shoes that are toonarrow in the toe region may lead to the formation of bunions [4][5]. Studiesreported that individuals with hallus valgus have lower thickness and cross-sectional area of abductor halluces and flexor halluces brevis, compared toindividuals without hallux valgus [6]. Generally, hallux valgus is caused byvarious factors, including inborn deformities, arthritis, trauma, and heredity[7]. It has been suggested that atrophied or weak toe flexor muscles areassociated with the formation of toe deformities. However, there is notenough evidence to support this theory. Nevertheless, high heels (forcingtoes into the front of shoes), ill-fitting shoes (too tight, too narrow or toopointed shoes make feet more susceptible to bunions) may increase thelikelihood of suffering this deformity [8]. Therefore, strengthening theintrinsic toe muscles may help reduce the incidence and severity of toedeformities in older adults [9]. Shoes and insoles need to conform to thewearer’s foot shape without squeezing or pressing any part of the foot [10].

Plantar fasciitis is acknowledged as synonym of inflammation ofthe plantar fascia and the suffix “-itis” integrally suggests an inflammatorydisease. It is common for doctors to confuse heel spurs and plantar fasciitis

Original Scientific PaperUDK: [572.087:611.986]:004.925.84

when a patient comes in for heel pain. Heel spurs are found in 70 percentof patients with plantar fasciitis, but these are two different conditions[11][12]. The heel spurs themselves are not painful; it is the inflammationand irritation caused by plantar fasciitis that can hurt. Heel spurs are oftenobserved on X-rays of patients who do not feel heel pain or plantar fasciitis[13]. Almost 10 percent of injuries occur among athletes whose activitiesinclude frequent running and jumping [14].

There are basically two kinds of arches: longitudinal arches(consisting of medial and lateral parts, distributing body weight andpressure in different directions together with transverse arches) andtransverse arches [15]. According to the research conducted by Subotnick,60% of the population have normal arches, 20% have a cavus foot (higharch), and 20% have a planus foot (low arch) [16]. When longitudinal archesare higher than normal, this is termed as high arch [17][18]. It has an imprintwith or without a narrow band connecting the forefoot and the heel region.The bony (over-supinated) structure on the lateral side of the foot is athigher risk of injury due to smaller area bearing the weight, therebytransmitting higher stresses to the foot and leg. A neurologic syndrome andother medical conditions often cause high arch (Cavus foot), e.g. cerebralpalsy, Charcot-Marie-Tooth disease, spina bifida, polio, muscular dystrophy,or stroke.

When longitudinal arches are low, this is referred to as planusfoot [19][20]. Planus foot, like cavus foot, does not transmit forces efficientlyand therefore may lead to foot ache. Moreover, this also affects properpressure distribution in other parts of body, which may cause back pains inlong term. This metamorphosis is the result of a greater inversion of the rearfoot that occurred at heel strike in the low-arched group [21].

Birtane et al. evaluated the effects of different obesity categorieson the plantar pressure values [22]. Their study examined the feet (left andright) of 50 participants classified as non-obese and class one obese,according to their body mass index values. Examined pressure zones wereas follows: peak phalanx pressure, medial forefoot peak pressure, middleforefoot peak pressure, lateral forefoot peak pressure, middlefoot peakpressure, rearfoot peak pressure, plantar contact area.

Veal et al. quantified the weight increase [23]. The authorsexamined whether the increase in weight had an impact on the mean peakfoot pressures by controlling the foot function, deformity, and structure.Novel's in-shoe dynamic pressure measuring system (Pedar system) hasbeen used to measure peak plantar foot pressures.

This part presents the main diseases and pathologies of the foot.Pathological assessments show that the knowledge and analysis of themorphology and anthropometry are decisional factors in the diagnosis of apodiatrist.

2. Morphological analysisMorphological analysis is a domain related to the proportion and

dimensions of anthropometric measures. Morphological knowledge isimportant in several domains because it can explain e.g. the cause ofphysiological ailments. The prominence of anthropometry has been playinga vital role in forensic research, in terms of identifying the victim's sex,population group and demographics [24]. In the footwear industry,anthropometry has been an important tool for optimizing shoe and insoleshapes according to different age groups, races, body composition andgender specifics. Many papers attempt to tackle the optimization problemand are connected to measurement campaigns. There are several basicmethods of foot measurement available on the market, such as caliperruler, blueprints, tape measures, etc. However, contemporary methodssuch as 3D foot-scanners appear more suitable. The plaster cast is aconvenient and cost-effective method, often used by orthopaedists to obtainthe 3D shape of the foot. However, 3D scanners prove more appropriate,cost-efficient and applicable for the creation of client database ormeasurement campaigns.

Our priority is to analyze 3D feet anthropometry, to examinestate-of-art methods of foot measurement and to verify or define thecorrelation between them.

2.1.Anthropometry of the footBy definition, anthropometry is the measurement technique of the

human body and its various parts. The measurement of a human body isstrongly related to different anthropometric points defined by the bones [25].Figure 1 shows different bones of the foot; the anthropometric points visiblefrom this point of view are marked red and green as an example.

In the case of scanning an entire human body, different planes(sagittal, frontal, transverse) partition it in order to prepare the measurementprocess [26], which is not the case with the feet. In the works of Witana etal. [27], the anthropometric points are the only measurement referenceswhich have been used to classify 18 dimensions by categories, accordingto the length between the two points and a plane, the width between twopoints and the girth of contours positioned with respect to one, two or threepoints. These 18 categories are as follows: foot length, arch length, heel tomedial malleolus, heel to lateral malleolus, heel to fifth toe, foot width, heelwidth, bimalleolar width, mid-foot width, medial malleolus height, lateralmalleolus height, height at 50% foot length, ball girth, instep girth, long heelgirth, short heel girth, ankle girth, waist girth.

To compare foot dimensions between the two genders and thecorresponding data from other populations, Hajaghazadeh et al. haveadded others dimensions [28]. Lengths of the second, third and fourth toemeasured in the direction of the Brannock Axis have been added to obtain21 dimensions in total.

Figure 1: Different bones of foot. Anthropometric points.

2.2 Foot measuring techniquesManufacturing comfortable footwear relies on anthropometric

research, which determines the morphological character of the foot, thefunctioning of the foot-footwear system and the results of the morpho-functional optimization of the shape of the product. Natural anatomic-morphological constructions of the foot and its correct static and dynamicfunctioning are ensured by a rational inner shape of the shoe, determinedby the construction of the shoe last. The construction of the shoe last andthe establishment of the dimensions necessary to meet the comfortrequirements of a larger proportion of consumers with minimal productioncosts must be based on knowledge and the most accurate characterizationof anatomic morphological differences between foot types frequentlyencountered within the targeted consumer population. For this purpose, itis necessary to periodically perform anthropometric studies of thepopulation according to certain criteria (sex, age, geographical region, etc.),in order to obtain information about the dimensional particularities of theaverage representative foot for that population, i.e. the laws of distributionof anthropometric parameters that characterize the representative averagefoot of the population of the respective country [29].

The most common approaches include the use of digital calipersfor direct measurements and 3D scanning and footprint analysis for indirectmeasurements. It is very important to provide adequate training for thetechnicians to correctly position landmarks on the proper anatomical points.

13

The main objective of taking measurements of the human foot isto determine the most precise dimensions of the foot, which enables thedesign of the shoe last, which is the physical support essential to shoedesign.

Traditional measurement methods, e.g. the ink footprint, digitalcaliper and Brannock Device are the traditional manual approaches used todetermine foot dimensions. However, the accuracy of digital calipermeasurement tends to be affected by human error. Different techniciansmay obtain inconsistent measurement results. It is very important to provideadequate training for the technicians to correctly position landmarks on theproper anatomical points [30]. Furthermore, it is necessary to respect therules and norms to obtain measurements with reliable results [31]. Othermeans of traditional measurements measure the length of the correctlyoriented foot, the strategic angles and anthropometric contour girths,correctly identified with respect to the anthropometric points.

The Digital Caliper (sometimes incorrectly called the DigitalVernier Caliper) is a precision instrument that can be used to measureinternal and external distances extremely accurately. McPoil et al. used thedigital calipter to measure and combine several anthropometricmeasurements to predict the plantar surface [32]. The six measures thatwere considered in the study are as follows: total foot length, ball length,dorsal arch height, forefoot width, midfoot width, heel width.

Designed in 1927, the Brannock Device is a foot-measuringdevice which has become a must in all retail footwear stores. Measuringaccuracy, quality construction, and simple, yet completely functionalmanually operated design have made genuine Brannock measuringdevices the standard in the footwear industry [27]. Although thismeasurement instrument is considered among the most reliable inmeasuring the lengths of the foot given its perfect alignment with theBrannock axis, some authors still use the traditional measuring tape in theirmeasurement campaigns [33][34]. These techniques somewhat lack up-to-the-mark precision in obtaining measurement which could be used foratypical morphologies.

3D digital measurement is usually performed with a 3D scannerof different types, depending on the desired measurement height. Thecompany BFTS Human Technology offers two versions of INFOOT 3Dscanner [35]. The first version can measure a height of 150mm, while thesecond version measures up to 250mm. The advantage of the secondproduct comes into play in boot design, which requires a deeper knowledgeof the upper part of the foot, or in the sector of orthosis. The 3D foot scanneruses the optical laser scanning technology. INFOOT scans a foot form fromthe anatomical landmark points, and automatically measures almost 20measuring items as maximum.

Witana et al. show a great interest in using the 3D foot scanner.In their study, the authors have compared the measurement results of a 3Dscanner with manual foot measurements. Their work highlights importantdifferences in measurement accuracy from the abovementionedmeasurement tools, along with the measuring protocol, measuring time andskill level of the measurer [27]. Lee et al. have also achieved similar resultsby comparing the scanner to conventional foot measurement methods, inparticular the digital caliper, ink footprint, and digital footprint [30]. The 3Dscanner has been an indispensable tool for the evaluation ofanthropometric parameter results obtained by 3D measurements and theirstatistical and mathematical processing in the works of Pantazi et al. [29].The 3D foot scanner has also been used by Nácher et al. for its accuracyand rapidity in classifying the feet of a population of 316 female participants.The aim of this study is to improve the comfort of shoes by designing amodel for predicting footwear fit on the basis of processed data [36].

In the podiatry sector, other techniques are used to directly obtainthe 3D form of the underside shape of the foot in creating orthopedic insolesadapted to the patient. One example is the box with double imprint [37] thatallows the realization of the 3D shape of the two feet in plaster or resin andthe design of orthopedic insoles. This manual technique is not expensivebut requires expertise in molding and the creation of the insole. Thisprocess could be conducted numerically and more quickly in CAD.

Manual measurement generally leads to measurement errors,depending on the operator and their fatigue if the measuring is performed

on many people. To avoid this type of problem, the industry has developeddifferent types of the 3D foot scanner. However, the measurement protocoland the exploitation of the results of these new foot measurement tools canaffect the precision of the measurements. Therefore, this paper intends toimplement own measurement method based on the 3D raw data of thescanner. These measurements will be compared with those obtaineddirectly by the software sold by the manufacturer of the selected scanner.An anthropometric analysis is necessary because it represents the core ofthe measurement process.

3. Anthropometric analysis and feetmeasurements3.1. Anthropometric points

Foot measurements depend essentially on the anthropometricpoints defined in precise places of its skeleton. The manual footmeasurement instrument, which is used and validated scientifically, is adevice that was invented by Brannock. The positioning of the foot in thisinstrument makes it possible to define a reference axis for themeasurements, i.e. the Brannock axis. As a general rule in case of a footthat does not have a deformation problem (typical deformation as anindicator of diseases), the reference axis is a virtual line between pternionand the tip of the second toe (A). Since there may be slight differencesbetween measurements obtained manually using a tape measure,Brannock's instrument and a 3D scanner, it seems important to recall theanthropometric points which are essential for foot measurement and theway these measures should be taken or interpreted, in order to find the bestcompromise between these different methods. 19 anthropometric pointswhich are recognized today are as follows:

1) Pternion :2) Metatarsal tibiale : Most medially prominent point on the 1st metatarsalbone3) Medial malleolus : Most medial point of medial malleolus4) Lateral malleolus : Most lateral point of lateral malleolus5n) Toe nth : nth toe tip6) Instep: Top of instep point7) Metatarsal fibulare : Most laterally prominent point on the 5th metatarsalbone8) Highest point of 1st metatarsal : Top of ball girth point9) Sphyrion :10) Sphyrion fibulare :11) Landing point : Back heel point12) Junction point :13 & 13’) Calcaneum points : Most medially and laterally prominent pointson the calcaneum bone14) Navicular :15) 5th metatarsal : Tuberosity of 5th metatarsal16) Toe 1st joint : Highest point of Toe 1st joint17) Toe 5st joint : Highest point of Toe 5st joint18) 1st metatarsal : Highest point of 1st metatarsal head19) Mid-foot highest point : Highest point of the vertical girth at 50% footlength from the pternion

Figure 2 shows the position of these points in relation to the footskeleton and the joints. In practice, these points will be positioned with aslight shift caused by the muscular surplus that surrounds the bonestructure.

14

Figure 2: Anatomical bones, anthropometric points.

3.2 Feet measurementsFoot measurements are generally classified into 4 categories

(lengths, heights, widths, and girths). The fifth category (angles) required forthe design of footwear products (sole, shoe) is derived from the previousmeasurements:

Lengths: The whole distances are measured along the Brannock axis (X-direction)

L1 - Foot length: distance from point 1 to the tip of the longest toe.L2 - Arch length: distance from point 1 to point 2.L3 - Heel to medial malleolus: length from point 1 to point 3L4 - Heel to lateral malleolus: length from point 1 to point 4L5 - Heel to fifth toe: distance from point 1 to point 5.L6 - Heel to Sphyrion: distance from point 1 to point 9.L7 - Heel to Sphyrion fibulare: distance from point 1 to point 10.Heights: The whole distances are measured in the vertical direction (Z-direction)H1 - Medial malleolus height: distance from the floor to point 3.H2 - Lateral malleolus height: distance from the floor to point 4.H3 - Height of instep: distance from the floor to point 6.H4 - Sphyrion height: distance from the floor to point 9.H5 - Sphyrion fibulare height: distance from the floor to point 10.H6 - Mid-foot Height: Maximum height measured with a line at 50% of footlength from point 1Widths: The whole distances are measured in the direction perpendicularto the Brannock axis (Y-direction). Errors may occur with this type ofmeasurement, because these distances may be the shortest distancebetween the measuring points in manual mode with a cephalometer or withsome 3D scanners.W1 - Foot width: distance from point 2 to point 7W2 - Bimalleolar width: distance from point 3 to point 4W3 - Mid-foot width: Maximum breadth measured with a line at 50% of footlength from point 1.

W4 – Heel width: distance from point 13 to point 13’Girths: This type of measurement can represent the contour drawn on theshape (e.g. scanner or CAD) or an equivalent contour representative of astretched tape measure.G1 - Ball girth: Girth of foot passing through point 2, point 8 and point 7.G2 - Instep girth: Smallest girth passing through point 6.G3 - Long heel girth: Girth of foot passing through point 6 and point 11.G4 - Short heel girth: Minimum girth passing through point 12 and point 11.G5 - Ankle girth: Horizontal girth passing through point 12.G6 – 50% foot length girth: Vertical girth at 50% foot length from point 1.Angles: Angle according to the sideline of the foot (plane B andsubsequently C)A1 - Toe 1st angle: Angle with the plan B.A2 - Toe 5th angle: Angle with the plan C.

3.3 Measurement protocol for 3D footscanner

The first measurement campaign was carried out to startdeveloping a sufficient database to validate our 3D graphical process. Feetof one hundred people were scanned. No distinction was made betweenthe feet of women and men. At this stage of the study, the morphology ofthe feet does not depend on sex. The distinction will be made only later inthe construction of footwear according to the population targets envisagedby the industry sector (i.e. the footwear industry).

The measuring device that has been used to scan the differentfeet in our database is the foot scanner of INFOOT society. Themeasurement protocol is imposed by the designer. In the first phase, 8patches must be glued on the foot of the scanned person so that thesoftware can size the overall volume of the foot (Figure 2).

A tactile analysis of the bones of the foot is carried out in order tobetter detect the following anthropometric points: metatarsal fibulare 7,sphyrion fibulare 10, lateral malleolus 4, instep 6, metatarsal tibiale 2,navicular 14, sphyrion 9, and medial malleolus 3 (Figure 3).

Five red stickers localize the points of reference for thecalculation of different anthropometric points and the positioning ofmorphological contours. Anthropometric reports on which the user canintervene contribute to the automatic calculation process and its calibrationif needed. Figure 3 shows the result obtained on the tested morphology.

Figure 3: Landmarks for the scan process.

Figure 4: Detection of anthropometric points and morphological curves onreal foot.

Figure 5 shows the results of measurements (lengths, widths,heights, angles and girth) taken under normal conditions of use of thescanner, i.e. the feet must be positioned between the two green lines.

15

Figure 5: Scan and measurements of feet.

4. 3D graphical processThis chapter discusses the implementation of a new method of

foot anthropometry. It is a very precise method that is applicable, or evenadaptable to each foot because it is semi-automatic, i.e. it is commandablewith a set of parameters specific to the morphology of the patient or client.Each step of the process must be rigorously followed, given theanthropometric links integrated into the process.

4.1 Outline encompassing the footprintThe first step of the 3D graphical process is to wedge the foot in

a trapezoid composed of six planes to define the geometry of the optimaloutline encompassing the footprint. Two techniques are used in order toacieve this and their goal is to find the contact area or areas between theplane perpendicular to the ground and the 3D shape of the foot.

As this is performed manually during the measurement of thefoot, it is essential to first wedge the heel on the vertical plane A to definethe zero of the coordinate system along the X axis, which allows to detectthe contact zone, providing an approximation of the position of point 1,called 1’ (Figure 2 & Figure 6a). Then the foot is translated and turned sothat it is stuck on the vertical plane-B to the plane-A, which leads to twocontact zones. In our process, the procedure is reversed since the foot isfixed and spotted in the absolute coordinate system R0(O,x,y) (Figure 6a).It is necessary to look for the plane-B before the plane-A. A movablecoordinate system R1(O1,x,y) is therefore designed in relation to R0 andcontrolled by two translations along the X and Y axes and a rotation alongthe Z axis. Two lines aligned on the X and Y axes of R1 supporting the twoplanes will be able to translate and rotate so that the areas can bevisualized by their associated planes.

Figure 6: Wedging the heel by two planes, detection of medial and lateralcontact points.

In the same way, plane-C has been positioned by a movablecoordinate system R2(O2,x,y) (Figure 6b). This coordinate system isdesigned relative to R1 and controlled by a translation along the Y axis anda rotation along the Z axis. The line aligned on the X axis of R2 supportingthe plane will translate and rotate so that it can be visualized the two zonesby its associated plane.

The plane-D enables the search for the angle of inclination of thefirst toe. It is positioned by a movable coordinate system R3(O3,x,y), whoseorigin O3 slides by translation on the line representing the Y axis of R1(Figure 7a). The coordinate system R3 pivots about its Z axis to managethe angle of inclination of its X axis, on which the line supporting thedetection plane of the contact zone with the foot is aligned.

The plane-E looks for the angle of inclination of the fifth toe(Figure 7b). It is positioned by a movable coordinate system R4(O4,x,y),whose origin O4 slides by translation on the line representing the Y axis ofR1. The coordinate system R4 pivots around its Z axis to manage the angle

of inclination of its X axis, on which the straight line supporting the detectionplane is aligned.

Figure 7: Detection of medial and lateral contact points of toes.

At this point in the process, it is required to locate the Brannockaxis. In the first phase, a median axis between the two planes-B and C iscreated to detect the point of intersection B1 between this axis and the lineassociated with the plane-A (Figure 8a). This point is the starting point B1

of the Brannock axis, because it represents the projection of theanthropometric point 1 (re-adjustment of point 1’) on the ground.

Figure 8: Detection of contact points 1, 52; creation of Brannock axis.

The other end is located at the end of the second toe (Figure 8b).The detection of this end goes through the creation of a movable coordinatesystem R5(O5,x,y), whose origin O5 slides by translation on the linerepresenting the X axis of R1. The reference R5 pivots about its Z axis tomanage the angle of inclination of its Y axis on which the line supporting thedetection plane F2is aligned. This angle must be adjusted so that the planeF2 is perpendicular to the Brannock axis. Once the endpoint 52 is found, itprojects on the right, representing the Y axis to create the second end B2 ofthe Brannock axis. This axis can then be plotted from B1. Then, a newcoordinate system R6(O,x,y) on the point B1 is created perpendicular to theBrannock axis (Figure 8a). A detection plane A’ is created from the linerepresentative of the X axis of R6 in order to readjust the final position ofpoint 1. The condition is that point 1 must be at the same height as in thearea detected by A’.

The outline encompassing the footprint can now be finalized bycreating the last F1 plane that detects the 51 end of the first toe (Figure 9a).This plane is aligned on the line representing the Y axis of a coordinatesystem R7(O7,x,y), whose origin O7 translates on the Brannock axis.Among other things, the Y axis of this coordinate system is perpendicular tothe Brannock axis. Figure 9b shows the detected contour which enablesthe location of anthropometric points.

Figure 9: Detection of contact point 51, outline encompassing the footprint.

4.2 Detection and measurement ofanthropometric pointsToes tip (51, 52, 53, 54, 55)

As with the first toe, different coordinate systems R8(O8,x,y)R9(O9,x,y) R10(O10,x,y) have been placed along the Brannock axis tocreate different lines representing the Y axis of each coordinate system(Figure 10a). Detection plans F3, F4, F5 were created on each line (Figure10b). The three end points 53, 54, 55 of the last toes detected by theseplanes are then projected onto the Brannock axis. The length of each toewith respect to B1 (projected from 1) can be measured directly on X axis ofthe coordinate systems of 51, 52, 53, 54, 55.

16

Figure 10: Detection of contact points 53, 54, 55.

Junction point (12) and landing point (11)

The junction point is defined from two inclined planes, plane G inthe oblique direction of the top of the foot (in side view), and plane H in thedirection of the contact zone of the lower part of the tibia (in side view)(Figure 11a). These two planes are perpendicular to the plane B and arecreated from two lines: one oriented along the X axis of coordinate systemR11(O11,x,y) and the other oriented along the Y axis of coordinate systemR12(O12,x,y) (Figure 11c). These coordinate systems rotate around the Yaxis of R1 in the XY plane of R1 in order to respect the perpendicularity. Theorientation of these coordinate systems and their relative position withrespect to the reference R1 make it possible to manage the zones oftangency of the planes in contact with the foot.

Then, a coordinate system R13(O13,x,y) is created at theintersection of the two lines defining the contact planes G and H. Thiscoordinate system has a Y axis aligned with the X axis of R11. A cylinder isthen created and centered at O13, its main axis being aligned on the Z axisof R13 (Figure 11b). The Z axis of R13 is also at the intersection of the twoplanes G and H. By modifying the diameter of this cylinder, the contact zoneof the heel representing the landing point 11 can be detected.

Figure 11: Detection of contact points 11, 12.

A cutting coordinate system R14(O14,x,y) is create from astraight line connecting the origin point O13 of R13 and the landing point 11that has been positioned and directed on the point 11 (Figure 11c). Theyellow curve resulting from the section of the foot by the cutting plane ofR14 represents the short heel girth G4. The junction point 12 is at theextremum of this curve in a vertical direction upwards.

Instep point (6)

The instep point 6 is a point detected with the plane G. It islocated in the lower part of the contact zone (Figure 12a). This point is oneof the three passage points of the curve of the instep girth G2. The secondpoint Ars is located at the upper part in the arch (Figure 12a). Theintersection between the plane B1 parallel to B and the foot makes itpossible to create a portion of the curve symbolizing the shape of theinternal arch. The third point Bmid is defined in the middle of two points Bmax,Bmin, located at the ends of the tangent areas of the plane C. These pointsare defined on the creation line of the plane G (Figure 12a). Since the Bmid

point does not belong to the surface of the foot, it is required to create aR15(O15,x,y) cut mark on 6 to create the G2 curve. The curve G’2 is a curveperpendicular to the Brannock axis, representing the instep girth G’2proposed by the foot scanner.

Figure 12: Detection of contact point 6.

Metatarsal tibiae (2), metatarsal fibulae (7), highest point of 1st

metatarsal (8)

The metatarsal tibial point 2 and metatarsal fibular point 7 can bedetected from the outline encompassing the footprint (Figure 13b).Intersections between the creation lines of planes B and D have beenconsidered for this determination, as well as planes C and E at the lowerlevel, i.e. the ground. These two points are sufficient to create the axis ofarticulation of the foot. A coordinate system R16(O16,x,y) is created at theend of this axis so that its X axis is on this axis of articulation (Figure 13a).Ball girth G1 is obtained with the XY cutting plane which is orientable alongthe X axis of R16 to detect the highest point of 1st metatarsal 8 (Figure 13c).The tibial metatarsal 2 and the metatarsal fibular 7 represent the extremepoints on the G1 curve in the X and -X directions (towards the outside of thefoot). The curve G'1 is a curve perpendicular to the ground aligned on theaxis of articulation, representing the ball girth G’2 proposed by the 3D footscanner.

Figure 13: Detection of contact points 2, 7, 8, 19.

Mid-foot highest point (19)

The curve representing the girth at 50% foot length from thepternion is obtained from a cutting coordinate system R17(O17,x,y), locatedalong the Brannock axis with the same method that was used for R8, R9,R10 (Figure 13b). On this curve, G6 detects the mid-foot highest point 19,which represents the extremum point in the direction of -Y (Figure 13c).

Medial malleolus (3), lateral malleolus (4)

The medial malleolus 3 and the lateral malleolus 4 are obtainedrespectively from two parallel planes B’, C’ to the planes B and C. For thesecond point, the second zone of contact has been taken into account,which is superior to the first (Figure 14ab).


Sphyrion (9), sphyrion fibulare (10)

The detection of Sphyrion 9 and fibular sphyrion 10 uses atechnique equivalent to points 3 and 4. The two detection planes B’’, C’’move a little deeper in the foot to surround the malleolus. At this point, it ispossible to create two curves surrounding each malleolus by locating theintersection between these two planes and the foot. The Sphyrion 9 and thefibulare sphyrion 10 are then at the lowest point of these, representing theextremum in -Z.


4.3 Measurement process analysisThe set of measurements necessary for the dimensioning of the

foot was calculated from the anthopometric points and morphologicalcurves that were detected and created by the 3D graphical process (Table1: L1 to G6). Table 1 compares the results obtained by the proposedmethod and the method used by the scanner. Since the scanner offers other

17

3D graphicalmeasurement

ScanMeasurement Error (%)

L1 - Foot 277.5 280.6 1.1L2 - Arch 200.6 203.4 1.3L3 - Heel to medial malleolus 68.1L4 - Heel to lateral malleolus 41.3L5 - Heel to fifth toe 229.6L6 - Heel to Sphyrion 63.2L7 - Heel to Sphyrion fibulare 50.1H1 - Medial malleolus 92.0H2 - Lateral malleolus 79.2H3 - Instep 77.9 75.9 2.6H4 - Sphyrion 65.5 67.8 3.3H5 - Sphyrion fibulare 63.4 78.3 21.7H6 - Mid-foot 75.2W1 - Foot 110.6W2 - Bimalleolar 70.8W3 - Mid-foot 95.2W4 - Heel 68.1 67.2 1.3G1 - Ball 276.9 (277.5) 278.7 0.6G2 - Instep 273.0 (267.7) 282.7 3.4G3 - Long heel 372.0G4 - Short heel 353.2G5 - Ankle 272.3G6 - 50% foot length 266.7L8 - Fibulare instep 166.6 175.7 5.1H7 - Arch or Navicular 29.9 38.6 22.5H8 - Top of 1st metatarsal 26.4 (53.2) 47.6 44.5 (11.7)W5 - Foot breadth 115.9 115 0.7A1 - Toe 1st 5° -8.4° 159A1 - Toe 5st 21.4° 4.9° 336

complementary measures (italic measurements) to the standard measures(scanner-specific terminology), these have been added to the list (L8 to A1)so that the comparison is complete.

The results show that all the foot sizing measures contain a verysmall error. Only the H5 measurement has a defect, mainly from thescanned measurement. Since this depends on the positioning of the patchthat has been glued to the foot of the scanned person to locate the fibularesphyrion, imprecision is naturally generated by this manual mode. Thesame problem occurred for H7 (patches positioned manually).

Since the scanner does not measure G as specified in thescientific bibliography (now G' for the scanner), point 8 has become a point8' for the scanner, which explains this difference for H8. This difference isstrongly reduced if the measurements are taken as practiced by thescanner (measures between parentheses for the 3D graphical process).

The measurement of the two angles is highly critical in the caseof the scanner. This measurement is very important for defining the basicshape of the insole, and it depends on the outline encompassing thefootprint.

Our measurement technique is based on the 3D foot shape,whereas the technique used by the scanner is different and is based on theline of the heel, thus leading to often negative angles.

Table 1 Measurement differences between 3D graphical and scanmeasurement.

5. ConclusionThis paper presents the 3D graphical process, which has been

developed to detect the anthropometric points of the foot. Theseanthropometric points are crucial to obtain all the measurementscharacterizing the foot shape and dimensions. This non-contactmeasurement method proposes a tracking technique using virtualadjustable planes.

The results were compared with the industrial measurement datafrom specific software and the 3D foot scanner. The overall results show agood match between the data measured with the 3D scanner and ourprocess. However, the industrial methods are very commentable becausethey depend on the positioning of the markers on the foot andanthropometric ratios integrated into the measurement process. Thisexplains the few differences in some measures. Among other things, theuse of anthropometric reports is undesirable and can lead to even moreerrors if the measured foot is out of the ordinary, i.e. with non-negligible

deformations. The advantage of our method is the ability to adapt to thisproblem, because it can be applied to feet with hallux valgus or hammertoedeformities commonly encountered during measurement campaigns, asdiscussed in further publications.

6. References

[1] Centre Hospitalier, “Le pied,” Bois de l’abbaye. .[2] J. A. DeBello, K. I. DeCoteau, and E. Beatty, “Taking A Novel Approach

To Hammertoe Surgery,” Podiatry Today, 2006. .[3] E. B. Neves, A. J. Almeida, C. Rosa, J. Vilaca-Alves, V. M. Reis, and

R. Mendes, “Anthropometric profile and diabetic foot risk: a cross-sectional study using thermography,” pp. 1–3, 2016.

[4] S. K. van de Velde, M. Cashin, R. Johari, R. Blackshaw, A. Khot, andH. K. Graham, “Symptomatic hallux valgus and dorsal bunion inadolescents with cerebral palsy: clinical and biomechanical factors,”Dev. Med. Child Neurol., vol. 60, no. 6, pp. 624–628, 2018.

[5] “Hallux valgus: only the handicap leads to the operation of the onion -Why Doctor,” Pourquoidoctteur.fr, 2016. [Online]. Available:https://www.pourquoidocteur.fr/MaladiesPkoidoc/1126-Hallux-valgus-seul-le-handicap-conduit-a-l-operation-de-l-oignon. [Accessed: 19-Jun-2019].

[6] S. Taş and A. Çetin, “Mechanical properties and morphologic featuresof intrinsic foot muscles and plantar fascia in individuals with halluxvalgus,” Acta Orthop. Traumatol. Turc., no. xxxx, pp. 3–7, 2019.

[7] J. Ragland, “How to get rid of bunions,” Getridofthings. .[8] R. O. N. B. Killian, G. S. Nishimoto, and J. C. Page, “Fo and an,” vol.

88, no. 8, pp. 365–374, 1998.[9] A. Paiva de Castro, J. R. Rebelatto, and T. R. Aurichio, “The

relationship between foot pain, anthropometric variables and footwearamong older people,” Appl. Ergon., vol. 41, no. 1, pp. 93–97, 2010.

[10] K. J. Mickle and C. J. Nester, “Morphology of the Toe Flexor Musclesin Older Adults With Toe Deformities,” Arthritis Care Res., vol. 70, no.6, pp. 902–907, 2018.

[11] A. Ladhani, “What are heel spurs?,” step-by-step foot care, 2015.[Online]. Available: https://stepbystepfootcare.com/blog/what-are-heel-spurs/. [Accessed: 21-Jun-2019].

[12] U. Chundru, A. Liebeskind, F. Seidelmann, J. Fogel, P. Franklin, andJ. Beltran, “Plantar fasciitis and calcaneal spur formation areassociated with abductor digiti minimi atrophy on MRI of the foot,”Skeletal Radiol., vol. 37, no. 6, pp. 505–510, Jun. 2008.

[13] H. Lemont, K. M. Ammirati, and N. Usen, “Plantar fasciitis: adegenerative process (fasciosis) without inflammation.,” J. Am.Podiatr. Med. Assoc., vol. 93, no. 3, pp. 234–7, 2003.

[14] L. Özgönenel, “Plantar Fasciitis,” Tech. Foot Ankle Surg., vol. 12, no.2, p. 109, 2013.

[15] J. D.B., Hollinshead’s Functional Anatomy of the Limbs and Back.Elsevier Health Sciences, 2008.

[16] T. F. Novacheck, “Review Paper The biomechanics of running,” GaitPosture, vol. 7, pp. 77–95, 1998.

[17] “Foot pain | Mast Cells & Collagen Behaving Badly.” .[18] J. G. Atwater, “Cavus Foot (High-Arched Foot) Video | Orthopedic

Doctor in Vero Beach, Florida.” .[19] G. Gijon-Nogueron, J. Montes-Alguacil, P. Alfageme-Garcia, J. A.

Cervera-Marin, J. M. Morales-Asencio, and A. Martinez-Nova,“Establishing normative foot posture index values for the paediatricpopulation: a cross-sectional study,” J. Foot Ankle Res., vol. 9, no. 1,p. 24, Dec. 2016.

[20] D. Carmody, P. Bubra, G. Keighley, and S. Rateesh, “Posterior tibialtendon dysfunction: An overlooked cause of foot deformity,” J. Fam.Med. Prim. Care, vol. 4, no. 1, p. 26, 2015.

[21] D. S. Williams, I. S. McClay, J. Hamill, and T. S. Buchanan, “Lowerextremity kinematic and kinetic differences in runners with high andlow arches,” J. Appl. Biomech., vol. 17, no. 2, pp. 153–163, 2001.

[22] M. Birtane and H. Tuna, “The evaluation of plantar pressuredistribution in obese and non-obese adults,” Clin. Biomech., vol. 19,no. 10, pp. 1055–1059, 2004.

[23] S. A. Vela, L. A. Lavery, D. G. Armstrong, and A. A. Anaim, “The

18

effect of increased weight on peak pressures: Implications forobesity and diabetic foot pathology,” J. Foot Ankle Surg., vol. 37, no.5, pp. 416–420, 1998.

[24] M. Voracek, M. L. Fisher, B. Rupp, D. Lucas, and D. M. T. Fessler,“Sex Differences in Relative Foot Length and PerceivedAttractiveness of Female Feet: Relationships among Anthropometry,Physique, and Preference Ratings. Perceptual and Motor Skills,”2007.

[25] Printerest, “Ankle anatomy.” .[26] A. Cichocka, P. Bruniaux, and I. Frydrych, “3D Garment Modelling -

Creation of a virtual mannequin of the human body,” Fibres Text.East. Eur., vol. 22, no. 6, pp. 123–131, 2014.

[27] C. P. Witana, S. Xiong, J. Zhao, and R. S. Goonetilleke, “Footmeasurements from three-dimensional scans: A comparison andevaluation of different methods,” Int. J. Ind. Ergon., vol. 36, no. 9, pp.789–807, 2006.

[28] M. Hajaghazadeh, R. Emamgholizadeh Minaei, T. Allahyari, and H.Khalkhali, “Anthropometric Dimensions of Foot in Northwestern Iranand Comparison with Other Populations,” Heal. Scope, vol. 7, no. 3,2018.

[29] M. Pantazi, A. M. Vasilescu, A. Mihai, and D. Gurau, “Statistical-mathematical processing of anthropometric foot parameters andestablishing simple and multiple correlations. Part 1: statisticalanalysis of foot size parameters,” Leather Footwear J., vol. 17, no. 4,pp. 199–208, Dec. 2017.

[30] Y.-C. C. Lee, G. Lin, and M.-J. J. J. Wang, “Comparing 3D footscanning with conventional measurement methods.,” J. Foot AnkleRes., vol. 7, no. 1, p. 44, 2014.

[31] D. Webb, D. V. Bernardo, and T. Hermenegildo, “Evaluating andImproving Footprint Measurement : Orientation and Lengths,”Anthropologie, pp. 277–287, 2006.

[32] T. G. McPoil, B. Vicenzino, M. W. Cornwall, and N. Collins, “Can footanthropometric measurements predict dynamic plantar surfacecontact area?,” J. Foot Ankle Res., vol. 2, no. 1, 2009.

[33] O. Vrdoljak, M. K. Tiljak, and M. Čimić, “Anthropometricmeasurements of foot length and shape in children 2 to 7 years ofage,” Period. Biol., vol. 119, no. 2, pp. 125–129, 2017.

[34] K. Hasanzadeh and K. Salehzadeh, “The Relationship betweenAnthropometric Indices in Children and their Kinetic Performances ofAgility , Balance and Foot Power The Relationship betweenAnthropometric Indices in Children and their Kinetic Performances ofAgility , Balance and Foot Power,” no. May 2015, 2016.

[35] “BFTS GmbH.” .[36] B. Nácher et al., “A footwear fit classification model based on

anthropometric data,” SAE Tech. Pap., vol. 1, no. May 2014, 2006.[37] “Boite ŕ empreintes double - Salembier Pédicurie Podologie.” .

19

PRIMJENA 3D SKENERA U FUNKCĲI DIGITALNE ANTROPOMETRĲESTOPALA (FootSABA 3D Foot Scanner)

Sarajko Baksa1, Ines Baksa2, Budimir Mĳović3

1Međimursko veleučilište u Čakovcu, Čakovec2SABALab, Zagreb3Sveučilište u Zagrebu, Tekstilno – tehnološki fakultet, Zagreb

E-mail: [email protected], [email protected], budimir.mĳ[email protected]

SažetakPersonalizacĳa dimenzĳa i oblika obuće od iznimnog je značaja i u današnje vrĳeme od strane interdisciplinarnih struka (medicinske, obućarske,ergonomske ...) priznata kao vitalno važna, glede toga jer pogrešno izvedena obuća neminovno rezultira s neželjenim patološkim stanjima stopala. Cilj ovogistraživanja bio je znanstveno utvrditi primjenu automatizirane 3D digitalizacĳe prostorne antropometrĳske izmjere stopala u odnosu na učestalost pogrešnoodabrane obuće na temelju tradicionalnih metoda izmjere i odabira. Među ispitanim entitetima, podjednako muškog i ženskog spola utvrđeno je da više oddvĳe trećine osoba nosi obuću koja ergonomski nĳe odgovarala temeljnim antropometrĳskim izmjerama obuće, kako u širini, tako ni u duljini njihovih stopala.Postoje medicinski dokazi da je nošenje neodgovarajuće obuće usko povezano s bolovima i ranama u stopalima, a trajnim nošenjem i patološkimpromjenama stopala, kao primjerice deformacĳom stopala i nožnih prstĳu. Tradicionalne metode determiniranja morfologĳe stopala u svom opseguuzimanja mjera nisu dovoljne da točno definiraju oblik i veličinu, za razliku od suvremenog pristupa uporabe 3D skenera i digitalnih metoda izmjera 3Dvirtualnih modela, koji su u mogućnosti iznimno precizno i brzo personalizirati veliki broj antropometrĳskih podataka morfologĳe stopala.

Ključne rĳečiStopalo, 3D virtualni model, 3D skener, antropometrĳsko mjerenje

1. UvodPrimjena 3D skenera u funkcĳi digitalne antropometrĳe stopala je

potencĳalno izgledna tehnologĳa budućnosti za ostvarenje potrebakorisnika, u obliku individualiziranih proizvoda. Pristalost i udobnost obuće,jedan je od temeljnih antropometrĳskih čimbenika korisnika. Modnodizajniranje i funkcionalno konstruiranje obuće je vrlo složen proces, gledepotrebnog zadovoljavanja dĳametralno suprotnih zahtjeva funkcionalnosti iestetike.

Obzirom na to da su bazni ulazni podaci antropometrĳske izmjerestopala korisnika, unutar ovog rada predstavit će se znanstvenaistraživanja i analiza rezultata izmjera tradicionalnim ručnim metodamauzimanja mjera stopala korisnika u suodnosu prema recentnim metodamauzimanja mjera stopala korisnika metodama korištenja specĳaliziranih 3Dprostornih skenogramskih mjernih sustava.

Povĳesno temeljna uloga obuće je zaštita, što je iznimnovažan dio ljudskog postojanja. Stopalo se u tradicionalnoj kineskoj medicinismatra kao drugo srce ljudskih bića, stopalo u biomehaničkom pogledupreuzima i kontrolira značajne i opasne sile udara između tla i ljudskogtĳela, glede toga jer stopalo pruža potreban doprinos u balansiranju istabilnosti mišićno - skeletnog sustava. Problemi sa stopalima su česti, urasponu od jednostavnih poremećaja, kroz složene bolesti pa sve dopatoloških deformacĳa zglobova [1].

Ljudska stopala, u nazivniku hoda, kao kretanja, u prosjekuživota čovjeka, u ekvivalentu, rezultiraju udaljenošću hoda od pet puta okozemlje, ali im i pored toga ljudi daju manje pažnje nego što zaslužuju irĳetko nose odgovarajuću i najbolju obuću [2]. Čimbenici koji ukazuju naodluku o kupnji kod potrošača su i nadalje antropometrĳski oblik kaonajvažnĳi funkcionalni čimbenik udobnosti i zajedno s izgledom i cĳenom,jedan je od najznačajnĳih elemenata razmatranja za korisnike prilikomkupovine nove obuće [3].

2. ANATOMĲA STOPALAU ergonomĳskom i biomehaničkom pogledu funkcionalno zdravo

stopalo je skladno usklađen mehanizam koji se sastoji od koštanihelemenata, mišića i tetiva.

Postoje tri dĳela koštanog okvira stopala; preplus, plus i prsti.Preplus se sastoji od sedam kratkih spužvastih kostĳu, koje su poredane udva reda. U prvom redu su: vrh, vrh u lateralnom obliku, srednji i medĳalniklin kostĳu. U stražnjem redu su RAM i peta kostĳu. Plus se sastoji od petkratkih tubularnih kostĳu, osnove oblika zglobova s kostima u obliku kockei klinova, njihove zglobne strukture su povezane sa strukturama kostĳuprstĳu. Prsti se sastoje od tri elementa: palčani, srednji i glavni. Palac seformira samo iz glavnog i srednjeg elementa, slika 1.

Slika 1. Anatomĳa stopala

Lukovi stopala su u biomehaničkom pogledu najvažnĳi strukturnielement stopala, koji određuje sve njegove funkcionalne sposobnosti.Zahvaljujući pravilno formiranim lukovima u ranoj mladosti, stopalo obavlja

Izvorni znanstveni radUDK: [572.087:611.986]:004.352.4(086.4)

20

niz potrebnih biomehaničkih I automatiziranih funkcĳa, kao primjerice;distribucĳu tĳela pri kretanju i podešavanju ravnoteže, ublažavanje udaracau tlo, odnosno generiranu sposobnost za ublažavanje, akumulacĳu iotpuštanje energĳe koja nastaje biomehanizmom hodanja.

Općenito, lukovi stopala rade kao sustav biomehaničkeamortizacĳe, pružajući maksimalnu udobnost pokreta s minimalnimposljedicama za tĳelo. Oštećenje ove veze može dovesti do poremećajacĳelog mišićno - skeletnog mehanizma, glede toga, jer je tĳelo kompleksnai jedinstvena cjelina, pri čemu se i najmanja promjena u bilo kojempojedinom dĳelu, izravno odražava na cjelokupni sustav. Tako primjerice,ravna stopala mogu uzrokovati oštećenje koljena, zglobova kukova,deformacĳe kralježnice i poremećaja rada, kao i biološke pozicĳe unutarnjihorgana. Navedeno je rezultat činjenice, da ako stopalo na odgovarajućinačin ne obavlja svoje funkcĳe (amortizacĳa, balans, itd), onda skeletnekonstrukcĳe više razine preuzimaju konstruktivne zadaće funkcĳa skeletnihelemenata niže razine (koljeno, kuk zglobova, kralježnica). A budući dabiološki izvorno nisu prilagođeni ovoj vrsti radnih zadataka i opterećenja,navedeni sustavi su u svakodnevici takvog nepravilnog korištenja mnogoranjivĳi i osjetljivĳi.

Uzdužni biomehanički luk stopala nalazi se na unutarnjem rubustopala, unutar uzdužnog svoda. Vanjski uzdužni luk nastaje mehanikommetatarzalnih kostĳu, kuboidom i kostima pete. Uloga vanjskog uzdužnoglučnog svoda je potporna funkcĳa u statičkim i dinamičkim tjelesnim radnimaktivnostima. Unutarnji uzdužni luk, za razliku od vanjskog luka, izvodi većibroj raznovrsnih biomehaničkih funkcĳa prigušivanja i elastičnosti, slika 2.

Slika 2. Anatomĳa vanjskog i unutarnjeg uzdužnog lučnog svoda stopala

Stopalo uobičajeno ima tri segmentalne točke biomehaničkepodrške Metatarzalnih kostĳu. Kod primjerice, spuštenih (ravnih) stopala,dolazi do antropometrĳskih promjena tih segmentalnih točaka. Takvepromjene radikalno utječu na promjenu biomehanike hoda i rezultirajuraznovrsnim poremećajima unutar mišićno – skeletnog sustava.

Ovaj specifičan dizajn u obliku svoda, formira se i održava na istinačin zahvaljujući raznim ligamentima i mišićima. Ligamenti ostvaruju ulogupasivnih elemenata, dok mišići djeluju kao aktivni entiteti i ostvarujujednako vrĳednu ulogu u funkcionalnoj strukturi stopala. Postoje tri skupinemišića u stopalu; unutarnji mišići koji su odgovorni za biomehaničkokretanje palca, vanjska skupina mišića za kretanje malog prsta, i središnjimišići koji sudjeluju u stvaranju biomehaničkih pokreta svih prstĳu [4].

3. METODE ODREĐIVANJA DIMENZĲASTOPALA

Tradicionalna metoda mjerenja, temelji se na određivanju duljinei širine gazišta obuće, mada bi kolokvĳalno bilo razumljivĳe ukoliko bi se teizmjere nazivale: duljina i širina gazišta – stopala. Za razliku od dvĳutemeljnih dimenzĳa tradicionalnog određivanja dimenzĳskih odnosa stopalaunutar postupaka konstrukcĳe obuće, suvremeni, digitalizirani pristupi, 3Dskeniranja stopala, unutar svojih akvizicĳskih metoda omogućuju dobivanjedaleko većeg broja mjernih pokazatelja, koji nisu samo unutar područjadužinskih vrĳednosti, već determiniraju i veći broj trodimenzionalnihindividualnih referenci korisnika.

3.1. Tradicionalna metodaKako bi se što pouzdanĳe odredila pristalost obuće, potrebno je

odrediti koji broj(eve) korisnik nosi, odnosno koja je korisnikova duljina iširina stopala, pri čemu je otegotna okolnost, različitost modela kalupa,različitih proizvođača. Prema slici 3 i 4, potrebno je izmjeriti duljinu i

širinu stopala, uz napomenu da je stopalo potrebno mjeriti u odgovarajućojčarapi (tanjoj za ljetnu, odnosno debljoj za zimsku obuću), kao i to da jepotrebno izmjeriti oba stopala, glede nejednakosti istih, a unutar daljnjihrazmatranja rabiti veću izmjerenu vrĳednost.

Slika 3. Tradicionalna ručna izmjera gazišta stopala [5]

Prema istom načelu obrisa tlocrtnog traga stopala, izmjeri se iširina na najširem dĳelu stopala, kao sekundarna mjera tradicionalnogmjernog postupka.

Slika 4. Tradicionalne izmjere duljine i širine gazišta stopala

Mnogi proizvođači uz dimenzĳu duljine, često označavaju i širinuobuće, načelno za; usko, srednje (normalno) i široko stopalo.

Dužina stopala je samo osnova u određivanju odgovarajućeveličine obuće. Za primjerice duljinu stopala, od 25,5 cm, u principuodgovara veličinski broj 41, ali zavisno od proizvođača mogu odgovarati ibrojevi; 40, 40,5, 402/3, 41, 411/3, 41,5, a nisu rĳetki ni slučajevi iz prakse,kada je za primjerice promatranu duljinu stopala, od 25,5 cm, bioodgovarajući i pristajali, i broj 38 ?!

Proizvođači, poglavito brendirane obuće, uglavnom na svojimproizvodima imaju, informativnu etiketu s brojevima u različitim mjernimjedinicama (EUR, UK, US, JPN ...), a često i mjeru izraženu u cm. Japanskamjera (JPN ili JP) je iznimno korisna, glede toga jer je također izražena ucm. Ta mjera, dužina u cm, je najbitnĳa za pouzdano određivanje, hoće liobuća pristajati, ili ne. Potrebno je da ta mjera bude barem nešto veća odizmjerene duljine stopala, iskustveno za otprilike 0,5 cm (dužina u cm =dužina stopala + 0,5cm).

Unutar tabele 1 dan je usporedni prikaz; dužine stopala,Mondopoint, kao i brojevi obuće EUR, UK, US, odnosno JP/CN. U recentnovrĳeme u opticaju je i tzv. Mondopoint mjerni sistem (u mm), koji zapravoodgovara mjeri u cm i kojim se pokušava standardizirati veličina obućeprema normnom nizu ISO 9407:1991 - "Shoe sizes—Mondopoint systemof sizing ... "

Važno je naglasiti da su tradicionalni postupci uzimanja mjera,vezani uz pripadnu tradicionalnu masovnu proizvodnju i prodaju obuće,

21

Tab. 1. Usporedni prikaz; dužine stopala, Mondopoint, kao i brojevi obuće EUR, UK, US, odnosno JP/CN

3.2. Digitalno 3D skeniranje stopala3D tehnologĳa digitalnog skeniranja ostvarila je svoj potencĳal u

posljednjih nekoliko godina. Koristi se u različitim područjima primjene,poput; medicine, znanosti, inženjerstva, vojne industrĳe, industrĳe videoigara i sl. [7].

Uporaba 3D tehnologĳe skeniranja za proizvodnju digitaliziraneprezentacĳe dĳelova ljudske anatomĳe u budućnosti ima potencĳal dapomogne promĳeniti način na koji je širok spektar proizvoda, sukladno iobuća, dizajniran, konstruiran i izrađen [8].

Postoji mnogo raznovrsnih tehnološki različitih aplikacĳa 3Dskeniranja za potrebe prostorne digitalizacĳe različitih dĳelova ljudskogtĳela. Analiza mogućnosti 3D skeniranja za modeliranje stopala, većegbroja istraživanja, pokazala je da su 3D skenovi vrlo pouzdani iznanstveno ponovljivi [9].

Projektiranje obuće kao trodimenzionalnog i prilagođenog, aličesto nepersonaliziranog proizvoda, je iznimno složen proces, obzirom nadĳametralno oprečne zahtjeve udobnosti i modnih trendova.

Digitalizirane 3D tehnologĳe, bilo uporabom, 3Dfotogrametrĳskih metoda, 3D strukturiranog svjetlosnog skeniranja ililaserskog skeniranja, u konačnici omogućuju, slika 5;

1. 3D skeniranje stopala,

2. Oblikovanje 3D modela stopala,

3. Pretvaranje u 3D koordinatni točkasti oblak modela stopala,

4. Usporedbu izvedenog 3D digitaliziranog modela stopala s realnimskeniranim stopalom,

5. Dizajn obuće i

6. Različite mogućnosti za proizvodnju prilagođene ili uporabomzahtjevnĳe obuće.

Slika 5. Digitalizirani proces 3D skeniranja stopala, izrade obuće iproizvodnje

Na slici 6. vizualiziran je proces; postave recentnog mjernogskenogramskog sustava (a), umjeravanja pomoću determiniranihfotogrametrĳskih kalibracĳskih panela (b, c), skeniranja mjernih entiteta (d,e), u ovom slučaju sustava značajke, mogućnosti skeniranja oba stopalaistovremeno i završne virtualizacĳe izvedenog 3D računalnog prostornogmodela snimanja stopala (f) [3].

Slika 6. Proces skeniranja; a) Postava, (b, c) Umjeravanje, (d, e) Akvizicĳai f) Virtualizacĳa skenograma

22

primjenljivi isključivo za uobičajeno - normalno i biometrĳski zdravo stopalo.

Svakako da postoje i slučajevi koji ne spadaju u ovu kategorĳukao sto su manje ili više usko ili široko stopalo, deblje stopalo u predjeluskočnog zgloba ili stopala s nekim oblikom urođenog ili stečenogdeformiteta, kao posljedica gojaznosti ili moguće patoloških oboljenja, a koji

vjerojatno zahtĳevaju drugačĳi suvremenĳi i personaliziranĳi pristupodređivanja odgovarajuće veličine obuće [6].

Kao dio sveobuhvatne dĳagnostike, antropometrĳskog i biomedicinskog stanja stopala, recentno se primjenjuju, troškovno učinkoviti,vrlo precizni i praktični FootSABA 3D skener stopala, SABALab – a, iliprimjerice 3D sustav skeniranja razvĳen od strane PolyU – a, prikazan naslici 7.

Slika 7. 3D skener stopala s prikazom mjernog i vizualizacĳskog zaslona[10]

Unutar reverzibilnih inženjerskih procesa, posebice u procesima3D skeniranja, uvĳek će biti i rezultata nesavršenosti tĳekom snimanjapodataka. Čak i najnaprednĳi komercĳalni 3D sustavi skeniranja od straneprogramskih inženjera ulažu iznimne napore, kako bi se sustavimaomogućila napredna digitalna 3D analiza prikupljenih podataka, no i poredtoga za dubinsku 3D analizu i manipulacĳu akviziranih prostornih izmjera ipodataka često se koriste i dodatni specĳalizirani analizatorski računalniprogrami, primjerice; Geomagic Studio™ [11].

4. EKSPERIMENTALNI RADDigitalni 3D Foot Capture and Measurement System "FootSABA"

by Sarajko Baksa, namĳenjen je prostornom 3D skeniranju stopala u ciljuizrade virtualnih 3D modela. Rezultat digitalne antropometrĳske izmjere jetrodimenzionalni oblak virtualnih koordinatnih točaka, koji predstavljamjereno tĳelo, konkretno na primjerima skeniranih entiteta u redu veličine;1.387 prostornih poligona, 3.241 prostornih rubnih duljina i 931 prostornokoordinatna verteksa, slika 8.

Slika 8. "FootSABA" proces skeniranja i virtualizacĳske analize 3Dskeniranog modela

Tradicionalna ručna metoda mjerenja provedena je metodamakoje su opće prihvaćene i koje se uobičajeno i svakodnevno strukovnoprimjenjuju prilikom određivanja dimenzĳa stopala, a sukladno uputamaprikazanim na slici 3 i 4. Mjerenje je provedeno antropometrĳskim mjernimalatima utvrđivanja ravninskih dimenzĳa (antropometrĳsko pomično mjerilo,nje. Schublehre).

U oba mjerenja izmjere su provedene na oba stopala, a kako seradilo prvenstveno o antropometrĳskim izmjerama, kako bi rezultati bili štosignifikantnĳi, ista su provedena na “bosim” stopalima.

Unutar tabele 2 dani su sumarni rezultati 30 mjernih entiteta, udimenzĳama duljine i širine stopala, za tradicionalnu ručnu i recentnu 3Ddigitaliziranu metodu računalne izmjere.

Tab. 2. Tabelarni prikaz sumarnih rezultata mjerenja

5. RASPRAVA I ZAKLJUČCIUtvrđena je i opće poznata činjenica da postoji značajna razlika

u podacima na prišivenoj deklaracĳi (etiketi) koja se nalazi na obući irealnom - izmjerenom stanju veličine obuće.

Preporuka je da se pri kupovini obuće tradicionalnom metodomdužinskog mjernog sustava, primjerice; mjerne vrpce, izmjeri dužina i širinaoba stopala, te da se u kupovinu krene s dimenzĳama koje su izmjerene navećem stopalu, obzirom da su stopala načelno različitih antropometrĳskihveličina. Također, glede dodatne pristalosti obuće, kao značajka udobnosti,preporuka je izvršiti i izmjeru duljine unutarnjeg gazišta kao i duljinu(izvađenog) uloška obuće, obzirom da su i to elementi koji u značajnoj mjeridoprinose udobnosti i pristalosti obuće.

I pored primjene svega navedenog, to ne mora značiti da ćeobuća biti odgovarajuća i pristajala, glede antropoloških različitosti, nesamo u duljini među stopalima, već i širini, kao i signifikantnim prostornimdimenzĳskim razlikama pojedinih segmentalnih presjeka. Tako seprimjerice u praksi često događa da ljudi i s medicinskog gledišta zdravimstopalima, teško ili nikako ne pronalaze odgovarajuću i pristalu obuću,glede toga jer im primjerice, po duljini gazišta lĳevog stopala odgovara broj;42, a po duljini desnog gazišta, broj; 43, odnosno, da im po duljini gazištaodgovara broj; 43, a po širini tog istog stopala, broj; 44.

S obzirom na ujednačeni skup mjernih entiteta na kojem seprovelo istraživanje unutar ovog rada i stručnosti osobe koja je provodilamjerenje, rasipanje rezultata je razmjerno malo, no i pored toga, jasno jeuočljiva razlika između antropometrĳskih izmjera lĳevog i desnog stopala,kao i preciznosti 3D sustava.

Glede razvoja sustava automatiziranog i digitalnog prostornoguzimanja 3D otiska stopala, više nema potrebe za odabirom dĳametralnosuprotnih odlika; između dobrog modnog izgleda i ergonomski pristale iantropometrĳski individualizirane i odgovarajuće obuće, sada je moguće,korištenjem recentnih 3D antropometrĳskih skenera (primjerice; FootSABA)imati oboje.

S obzirom na iznimno veliki broj prostornih antropometrĳskihtočaka koje su rezultat 3D izmjere, primjerice; samo u domeni ravninskihizmjera, više od 3.000 prostornih preciznih podataka rubnih duljina,naspram dvĳe tradicionalno rezultirajuće, 3D FootSABA antropometrĳskiskener stopala, ostvaruje povećanje u rezolucĳi analize i modeliranja odnevjerojatnih 150.000% i to samo unutar područja ravninskih izmjera.

6. LITERATURA[1] B. Nácher, S. Alemany, J. González, E. Alcántara, J. García

Hernández, S. Heras and A. Juan; "A Footwear FitClassificationModel Based on Anthropometric data,"

[2] T. S. o. C. a. Podiatrists; "Footwear: A guide to choosing the bestshoes for your feet".

[3] E. Piperi, L. M. Galantucci, J. Kacani, E. Shehi, T. Spahiu; “From 3Dfoot scans to footwear designing & production“, 6th InternationalConference of Textile, 20, November 2014, Tirana, Albania

[4] https://rossiyanka-sanatoriy.ru/906-ploskostopie-plantografija(downloads; 20 July 2019)

23

[5] https://www.saptac.hr/kako-se-izmjeriti(downloads; 07 July 2019)[6] http://cafe.limundo.com/thread-276.html[7] R. Nibedita, K. Asimananda, Z. Yi Fan and L. Ameersing, "3D Foot

Scan to Custom Shoe Last," vol. 1, 2010.[8] S. Telfer and J. Woodburn, "The use of 3D surface scanning for the

measurement and assessment of the humanfoot", JOURNAL OFFOOT AND ANKLE RESEARCH, p. 9, 2010

[9] D. Besliu, "Measurement Devices for Custom Shoe Manufacturing,2011

[10] www.polyu.edu.hk/cpa/milestones/en/201506/knowledgetransfer/3dscanner creates a whole new footwear experie/index.html (14 July2019)

[11] 3DSystems, http://www.geomagic.com/en/products/studio(downloads; 12 July 2019)

AcknowledgementsThis paper describes the results of research being carried out

within the project “Centar održivog razvoja”/"Center of sustainabledevelopment", cofinanced by the European regional development fund andimplemented within Operational Programme Competitiveness andCohesion 2014 – 2020, based on the call "Investing in OrganizationalReform and Infrastructure in the Research, Development and InnovationSector".

24

3D SCANNER APPLICATION IN THE FUNCTION OF DIGITAL FOOT ANTROPOMETRY(FootSABA 3D Foot Scanner)

Sarajko Baksa1, Ines Baksa2, Budimir Mĳović3

1Međimursko veleučilište u Čakovcu, Čakovec2SABALab, Zagreb3Sveučilište u Zagrebu, Tekstilno – tehnološki fakultet, Zagreb

E-mail: [email protected], [email protected], budimir.mĳ[email protected]

SummaryThe personalization of footwear in terms of dimension and shape is of the utmost importance and is nowadays considered vitally important byinterdisciplinary professions (medical, footwear, ergonomics ...), since inadequately manufactured footwear inevitably results in unwanted pathologicalconditions of the feet. The aim of this study is to scientifically determine the application of automated 3D digitization of spatial anthropometric footmeasurement in relation to the frequency of incorrectly selected footwear based on traditional methods of measurement and selection. Among the examinedindividuals, both male and female, it was found that more than two thirds of people wear footwear that ergonomically does not fit the basic anthropometricfootwear measurements, both in width and length of their feet. There is medical evidence that wearing inappropriate footwear is closely related to pain andwounds on the feet, and that prolonged wearing leads to pathological changes of the feet, such as foot and toe deformation. In the scope of taking measures,traditional methods of determining foot morphology are not sufficient to accurately define the shape and size, in contrast to the modern approach of using3D scanners and digital methods of measuring virtual 3D models, which enable a very accurate and quick personalization of a large amount ofanthropometric data concerning foot morphology.

KeywordsFoot, 3D virtual model, 3D scanner, anthropometric measurement

1. INTRODUCTION

The application of 3D scanners for digital foot anthropometry is apotentially promising technology of the future that will meet the needs ofcustomers in the form of individualized products. Shoe fit and comfort areamong the fundamental anthropometric factors for the customer. Fashiondesign and construction of functional footwear is a very complex process,especially considering the attempt to meet the requirements for bothfunctionality and esthetics, which are often diametrically opposite andmutually exclusive.

Considering that the basic input data are anthropometricmeasurements of customers’ feet, this paper will present scientific researchand analysis of measurement results obtained using traditional manualmethods in comparison to recent methods of specialized 3D spatialscanning measurement systems.

Historically, the fundamental role of footwear is protection, whichis an exceptionally important part of human existence. In traditional Chinesemedicine, the foot is considered the second heart of the human body. Inbiomechanical terms, the foo controls significant and dangerous impactforces between the ground and the human body, since the foot provides thenecessary contribution to the balance and stability of the musculoskeletalsystem. Foot problems are common, ranging from simple disorders tocomplex diseases and even pathological joint deformities [1].

In the average human life, human feet walk the distanceequivalent to five times around the earth, but in spite of that, people givethem little attention [2]. Anthropometric shape is the most importantfunctional factor of comfort that influences the consumer's purchasedecision, along with the appearance and the price [3].

2. FOOT ANATOMYIn ergonomic and biomechanical terms, a functionally healthy

foot is a harmoniously coordinated mechanism consisting of boneelements, muscles and tendons.

There are three parts of the foot’s bone frame: tarsus, metatarsusand phalanges. The tarsus consists of seven short spongy bones,organized in two rows. The first row consists of the cuboid, navicular,medial, intermediate and lateral cuneiform. Talus and calcaneus (heelbone) form the back row. The metatarsus consists of five short tubularbones, resembling the shape of cube and wedges. Their joint structures areconnected to the structures of the phalanges. Toes consist of threeelements: proximal, middle, and distal phalanges. Big toe consists only ofproximal and distal phalanges, Fig. 1.

Figure 1. Foot anatomy

In biomechanical terms, the arches of the foot are the mostimportant structural elements of the foot, which determine all its functionalabilities. If the arches are properly formed at an early age, the foot performsa number of necessary biomechanical and automated functions, such asthe distribution of body weight when moving, adjusting the balance of thebody, mitigating impacts to the ground, i.e. the foot has an inherent abilityto mitigate, accumulate and release the energy generated by the walkingmechanism.

Generally, the arches of the feet function as a biomechanicalamortization system, providing maximum movement comfort with minimalconsequences to the body. Their damage can lead to the disruption of theentire musculoskeletal mechanism, because the body is a complex andunique unit, wherein the slightest change in any particular part canreflect directly on the whole system. For example, flat feet can cause

Original Scientific PaperUDK: [572.087:611.986]:004.352.4(086.4)

25

damage to the knee, hip joints, spinal deformities, as well as disorders offunction and biological position of the internal organs. These ailments occuras consequences to the inappropriate function of the foot (amortization,balance, etc.), causing the higher-level skeletal structures to assume thestructural functions of lower-level skeletal elements (knee, hip joints, spine).Since the former are not biologically and inherently adapted to this type ofwork and load, these systems are much more vulnerable and sensitive tosuch daily misuse.

The longitudinal biomechanical arch of the foot is located on theinner side of the foot, within the longitudinal plantar vault. The outerlongitudinal arch is formed by the mechanics of metatarsal bones, cuboidand calcaneus. The outer longitudinal arch has a supporting function instatic and dynamic physical work activities. In contrast to the outer arch, theinner longitudinal arch performs a greater variety of biomechanicalfunctions of amortization and elasticity, Figure 2.

Figure 2. Anatomy of the outer and inner longitudinal arch of the foot

The foot generally has three segmental points ofbiomechanical support of the metatarsal bones. For example, flat feet(flattened arch) cause anthropometric changes of these segmental points.Such changes radically affect the alteration of gait biomechanics and resultin various disorders.

This specific vault-shaped design is formed and maintained byvarious ligaments and muscles. Ligaments play the role of passiveelements, while muscles act as active entities and play an equally valuablerole in the functional structure of the foot. There are three groups of musclesin the foot; the internal muscles that are responsible for the biomechanicalmovement of the big toe, the external muscle group for the movement of thelittle toe, and the central muscles involved in the creation of biomechanicalmovements of all toes [4].

3. DETERMINING FOOT DIMENSIONSThe traditional method of measurement is based on the

determination of length and width of the shoe tread, although colloquially itwould be more comprehensible to call them length and width of thefootprint. In contrast to the two basic dimensions measured in traditionaldetermination of dimensional relations of the foot within footwearconstruction processes, digitized 3D foot scans allow for a far greaternumber of measuring indicators within their acquisition methods. Theseindicators are not only within the range of length values, but also determinea larger number of 3D individual references of the customer.

3.1. Traditional methodIn order to determine the suitability of the footwear as accurately

as possible, it is necessary to determine what size(s) the customer wears,i.e. the customer’s foot length and width, whereby the aggravatingcircumstance is the diversity of shoe mold models from differentmanufacturers.

As shown in Figures 3 and 4, it is necessary to measure thelength and width of the feet, noting that the foot should be measured in asuitable sock (summer or winter footwear), and that both feet should bemeasured due to foot inequality. It is advisable to use the greater measuredvalue in further considerations.

Figure 3. Traditional manual measurement of the foot [5]

According to the same principle of contouring the footprint, thewidth at the widest part of the foot is measured as a secondary measure inthe traditional measurement procedure.

Figure 4. Traditional length and width measurements of the foot [5]

In addition to the length dimension, many manufacturers oftendesignate the width of the footwear, usually for narrow, medium and widefoot.

Foot length is just the basis for determining the proper shoe size.For example, a foot length of 25.5 cm generally corresponds to size 41, butdepending on the manufacturer, it may also correspond to sizes 40, 40.5,40 2/3, 41, 41 1/3, 41.5. However, it is common for the observed foot lengthof 25.5 cm to correspond to e.g. size 38 in practice.

Manufacturers, especially of branded footwear, mainly put a labelwith numbers in different units of measurement (EUR, UK, US, JPN ...) ontheir products, and often the measurement expressed in cm. The Japanesemeasure (JPN or JP) is very useful because it is also expressed in cm. Thismeasure of length in cm proves most reliable for determining whether ashoe fits. This measure should be at least slightly larger than the measuredfoot length, experientially by approximately 0.5 cm (length in cm = footlength + 0.5 cm).

Table 1 shows a comparative view of the foot length, Mondopoint,and various shoe sizes expressed in EUR, UK, US, and JP/CN. Recently,there is also the so called Mondopoint measuring system (in mm), whichactually corresponds to the measure in cm and which attempts tostandardize the size of the footwear according to the standard series ISO9407: 1991 - "Shoe sizes - Mondopoint system of sizing".

It is important to emphasize that the traditional methods of takingmeasures, related to the associated traditional mass production and sale ofthe footwear, are applicable only to normal and biometrically healthy foot asthe standard.

There are certainly many cases that do not fall into this category.Such cases include a more or less narrow or wide foot, a thicker foot, or afoot with some sort of congenital or acquired deformity as a result of obesityor possibly pathological diseases, which are likely to require a different,more modern and personalized approach to determine the appropriateshoe size [6].

26

Table 1. View of the foot length, Mondopoint, and various shoe sizes expressed in EUR, UK, US, and JP/CN

3.2. Digital 3D foot scanning3D digital scanning technology has reached its potential in the

last few years. It is used in various areas of application such as medicine,science, engineering, military, video games industry, etc. [7].

The use of 3D scanning technology to produce a digitizedpresentation of human anatomy parts in the future has the potential to helpchange the design of a wide range of products, including properly designed,constructed and manufactured footwear [8].

There are many different, technologically diverse 3D scanningsoftware programs for the spatial digitization of different parts of the humanbody. Analysis of a large number of studies of 3D scanning capabilities forfoot modeling showed that 3D scans are highly reliable and scientificallyreproducible [9].

Designing footwear as a three-dimensional customized, but oftennon-personalized product is an extremely complex process, given thediametrically opposed demands of comfort and fashion trends.

Digitized 3D technologies, whether by the use of 3Dphotogrammetric methods, 3D structured light scanning, or laser scanning,ultimately enable the following (Figure 5):

1. 3D foot scanning,

2. Designing of 3D foot model,

3. Converting to 3D coordinate point cloud of foot model,

4. Comparison of derived 3D digitized foot model with the realscanned foot,

5. Footwear design and

6. Different options for the production of custom or more demandingfootwear.

Figure 5. Digitized process of 3D foot scanning, footwear construction andmanufacturing

Figure 6 shows the following processes: setup of a recentmeasurement scanning system (a), calibration using deterministicphotogrammetric calibration panels (b, c), scanning of measuremententities (d, e), which in this case features simultaneous scanning of bothfeet, and finally the final virtualization of the derived 3D computer spatialmodel of feet imaging (f) [3].

Figure 6. Scanning process; a) Setup, (b, c) Calibration, (d, e) Acquisition,and f) Virtualization of the scan

As of recently in use as a part of comprehensive diagnostics ofanthropometric and biomedical foot conditions, the cost effective, highly

27

accurate and practical tools FootSABA 3D foot scanner with SABALab andthe 3D scanning system developed by PolyU are shown in Figure 7.

Figure 7. 3D foot scanner with measurement and visualizationdisplay [10]

Within reversible engineering processes, especially in 3Dscanning, there will always be imperfect results when recording data. Eventhe most advanced commercial 3D scanning systems produced by softwareengineers are making tremendous efforts to enable the systems to conductan advanced digital 3D analysis of collected data; additional specializedcomputer programs for analysis are hence often used for a thorough 3Danalysis and manipulation of acquired spatial measurements and data, e.g.Geomagic Studio ™ [11].

4. EXPERIMENTAL WORKThe digital 3D Foot Capture and Measurement System

"FootSABA" by Ph.D. Sarajko Baksa is intended for spatial 3D footscanning for the purpose of creating virtual 3D models. The result of digitalanthropometric measurement is a three-dimensional virtual coordinatepoint cloud, which represents a measured body, specifically on examples ofscanned individuals in order of magnitude: 1,387 spatial polygons, 3,241spatial boundary lengths and 931 spatial coordinate vertices, Figure 8.

Figure 8. "FootSABA" process of scanning and virtualization analysis of a3D scanned model

The traditional manual measurement was carried out by methodsthat are generally accepted and commonly and professionally applied ondaily basis for determining foot dimensions, in accordance with theinstructions shown in Figures 3 and 4. The measurement was carried outwith anthropometric measuring tools for determining plane dimensions.

In both types of measurements, primarily anthropometricmeasurements were taken on both systems to conduct an advanced digital3D analysis of collected data; additional specialized computer programs foranalysis are hence often used for a thorough 3D analysis and manipulationof acquired spatial measurements and data, e.g. Geomagic Studio ™ [11].

Table 2 summarizes the results of 30 measured individuals, usingthe traditional manual and recent 3D digitized computational method formeasuring dimensions of foot length and width.

Table 2. Table of the summary measurement results

5. DISCUSSION AND CONCLUSIONSThis research also established the well-known fact that there is a

significant difference between the data on the sewn declaration (label)found on the footwear and the real - measured condition of the footwearsize.

It is recommended to measure the length and width of both feetusing traditional method of length measuring system such as e.g.measuring tapes when shopping for footwear. The purchase should bemade in accordance with dimensions that are measured on a larger foot,since feet are generally of different anthropometric sizes. With regard to theeven better fit of the footwear, it is recommended to measure the length ofthe inner footprint as well as the length of the (removed) shoe insert, sincethese are also elements that significantly contribute to shoe comfort andfitting.

Even if all of the abovementioned parameters are taken intoaccount, this does not necessarily mean that the footwear will beappropriate and fitting in terms of anthropological differences, not only inlength between feet but also in width, as well as in significant spatialdimensional differences of individual segmental sections. In practice, evenpeople with medically healthy feet often find it difficult or impossible to findappropriate and well-fitting footwear. The common case is that the length oftheir left foot corresponds to size 42, and the length of their right footcorresponds to size 43; or in other case, the length of their foot correspondsto the size 43, and the width of that same foot corresponds to 44.

Given the uniform set of measured dimensions examined withinthis work and the expertise of the person who conducted themeasurements, the scattering of the results is relatively small, butnonetheless, the difference between the anthropometric measurements ofthe left and right feet is clearly noticeable, as well as the precision of the 3Dsystem.

With regard to the development of automated and digital systemsfor the spatial imaging of 3D footprints, there is no longer a need to choosebetween diametrically opposite features: attractive and fashionablefootwear or ergonomically fit, anthropometrically individualized andappropriate footwear. It is now possible to have both, using recent 3Danthropometric scanners (e.g. FootSABA).

Regarding the extremely large number of spatial anthropometricpoints resulting from the 3D measurement in comparison with twotraditional methods, the anthropometric foot scanner 3D FootSABAachieves an increase in analysis and modeling resolution of an incredible150,000% solely within the domain of e.g. plane measurements with morethan 3,000 accurate spatial boundary length data.

6. LITERATURE[1] B. Nácher, S. Alemany, J. González, E. Alcántara, J. García-

Hernández, S. Heras and A. Juan; "A Footwear FitClassificationModel Based on Anthropometric data,"

[2] T. S. o. C. a. Podiatrists; "Footwear: A guide to choosing the bestshoes for your feet".

28

[3] E. Piperi, L. M. Galantucci, J. Kacani, E. Shehi, T.

Spahiu; “From 3D foot scans to footwear designing & production“, 6thInternational Conference of Textile, 20, November 2014, Tirana,Albania

[4] https://rossiyanka-sanatoriy.ru/906-ploskostopie-plantografija(downloads; 20 July 2019)

[5] https://www.saptac.hr/kako-se-izmjeriti(downloads; 07 July 2019)

[6] http://cafe.limundo.com/thread-276.html

[7] R. Nibedita, K. Asimananda, Z. Yi Fan and L. Ameersing, "3D FootScan to Custom Shoe Last," vol. 1, 2010.

[8] S. Telfer and J. Woodburn, "The use of 3D surface scanning for themeasurement and assessment of the humanfoot", JOURNAL OFFOOT AND ANKLE RESEARCH, p. 9, 2010

[9] D. Besliu, "Measurement Devices for Custom Shoe Manufacturing,"2011

[10] www.polyu.edu.hk/cpa/milestones/en/201506/knowledge transfer/3dscanner creates a whole new footwear experie/index.html (14 July2019)

[11] 3DSystems, http://www.geomagic.com/en/products/studio(downloads; 12 July 2019)

AcknowledgementsThis paper describes the results of research being carried out

within the project “Centar održivog razvoja”/"Center of sustainabledevelopment", cofinanced by the European regional development fund andimplemented within Operational Programme Competitiveness andCohesion 2014 – 2020, based on the call "Investing in OrganizationalReform and Infrastructure in the Research, Development and InnovationSector".

29

Automobilske navlake od prirodne kože – svojstva i problematikašivanja

dr. sc. Beti Rogina-Car, dr. sc. Stana Kovačević, prof.Sveučilište u Zagrebu Tekstilno-tehnološki fakultet

E-mail: [email protected]

SažetakU radu je dan pregled materĳala i specifičnosti izrade automobilskih navlaka u prometalima. Naglasak je na prirodnoj koži koja predstavlja jedan odnajluksuznĳih materĳala za izradu automobilskih navlaka. Obrađena su njezina svojstva, prednosti i nedostatci u odnosu prema tekstilnim materĳalima.Jedan od najizazovnĳih zadataka u izradi automobilskih navlaka jest kvaliteta odgovarajućeg šava. Posebna pozornost posvećena je krojenju i šivanjuprirodne kože namĳenjene automobilskim navlakama. Prirodna koža je specifičan prirodni materĳal koji daje dozu luksuza automobilskim sjedalima iinterĳeru automobila. Njezina dugotrajnost, cĳena i manja tržišna ponuda dovodi do manje primjene za automobilske navlake u odnosu prema tekstilnimmaterĳalima, ali je zato iznimno poželjna. Prema dosadašnjim istraživanjima krojenje i šivanje kožnih automobilskih navlaka zahtĳeva veću pozornost priodabiru odgovarajuće kože, šivaćeg stroja, konca, igle i tipa šivanog šava, koji će dati zadovoljavajuća svojstva automobilskoj navlaci u svim njezinimsegmentima. Ovaj rad pridonosi stručnim saznanjima i specifičnostima vezanim za prirodnu kožu, njezinu namjenu za automobilska sjedala te odgovarajućukvalitetu šivanog šava.

Ključne rĳečiprirodna koža, automobilska navlaka, svojstva prirodne kože, šivani šav.

1. UvodMaterĳali koji se upotrebljavaju za automobilske navlake u

prometalima izrađeni su od različitih materĳala raznim tehnološkimprocesima. Prirodna koža jedan je od najskupljih, ali i najpoželjnĳihmaterĳala koji se upotrebljava za automobilske navlake i interĳerautomobila. Svojim iznimno lĳepim i luksuznim izgledom privlači kupca tepridonosi

Slika 1. Prirodna koža [1]

Za izradu kožnih automobilskih navlaka upotrebljavaju seiznimno čvrste prirodne životinjske kože: bikova, kravlja, teleća, konjska,svinjska, kozja i ovčja koža. Koža je vrlo izdržljiv i otporan materĳal, aliistodobno elastičan i dišljiv. Pozitivna svojstva prirodne kože jesu: visokačvrstoća, elastičnost, otpornost na abrazĳu, dobra propusnost zraka,mekoća i glatkoća. Zbog visoke cĳene i iznimno dobrih svojstava prava sekoža uglavnom ugrađuje u skuplje automobile kod kojih kupac želi posebani originalan interĳer [2].

2. Svojstva prirodne kožePrerada životinjske kože pripada najstarĳim ljudskim

djelatnostima. To potvrđuju bilješke na babilonskim glinenim pločicama iz1250. godine prĳe Krista. Čovjek je kožu upotrebljavao od svojeg postankakako bi se zaštitio od vanjskih utjecaja, napada ljudi i životinja, Slika 2. [3,4].

Slika 2. Neandertalac, Hušnjakovo brdo kod Krapine [3]

S vremenom se koža osušila i postala tvrda. Izložena vlazi počelaje gnjiljeti te se raspadati. Postupkom štavljenja koža dobiva potrebnutrajnost. Prvi postupci štavljenja bili su dimljenje i obrada kože mastima imoždinama ubĳenih životinja. Danas se postupak štavljenja provodi urotirajućim bačvama u trajanju od 10 do 12 sati. Štavila mogu bitianorganske soli: kromove, aluminĳeve, cirkonĳeve; biljna štavila: ekstraktinekih tropskih i suptropskih biljaka. Primjena štavila omogućavaumrežavanje kolagenskih vlakna čime koža zadržava mekoću i elastičnostte postaje čvršća, otpornĳa na truljenje, manje propusna za vodu itd. Kožase prema podrĳetlu dĳeli na prirodnu i umjetnu kožu; prema prirodnom

Stručni radUDK: 675.14.017:629.3.04

30

izvoru dĳeli se na goveđu (teleću), ovčju, kozju, svinjsku, konjsku,aligatorovu, zmĳsku kožu itd.; prema svrsi postoji koža za obuću, odjeću,galanterĳu, automobilsku i zrakoplovnu industrĳu te za industrĳu namještajaitd. [4]

Na izgled i kvalitetu prirodne kože utječu životni uvjeti u kojima ježivotinja uzgojena. Tragove na koži ostavljaju ubodi insekata, rane, ožiljci,vene, bore, oznaka brenda itd., Slika 3.[5]

Slika 3. Tragovi – prirodna obilježja na koži životinja [5]

Svojstva prirodne kože koja su važna za primjenu uautomobilskoj industrĳi kod automobilskih navlaka jesu: otpornost naabrazĳu, otpornost na plĳesan, otpornost na dugotrajna i cikličkanaprezanja, elastičnost, čvrstoća, stabilnost oblika, mekoća i ugoda pridodiru s tĳelom, svojstvo dišljivosti, rubovi iskrojenih dĳelova se ne osipaju,lako održavanje [1]. U Tablici 1. prikazana je usporedba svojstava nekihmaterĳala koji se primjenjuju za automobilske navlake [6].

Tablica 1. Usporedba materĳala koji se primjenjuju za automobilske navlake [6]

+ dobar; ++ vrlo dobar; +++ izvrstan

Iz Tablice 1. vidljivo je da prirodna koža u usporedbi s ostalimmaterĳalima ima vrlo dobra svojstva. Ako se usporedi s antilopom, može sevidjeti velika razlika u svojstvima. Razlog u takvoj razlici svojstava jest utome što se antilop proizvodi od donjeg dĳela životinjske kože koja jemekša, ali osjetljivĳa na druga svojstva.

3. Automobilske navlake od prirodne kožePrimjer dobre prakse jest tvrtka Wollsdorf Leather koja se

specĳalizirala za proizvodnju kože namĳenjene automobilskoj izrakoplovnoj industrĳi te industrĳi namještaja. Predvodnik je u štavljenjuprirodne kože bez kroma. Upotrebljavaju prvoklasne goveđe kožepodrĳetlom uglavnom sa srednjoeuropskog prostora [7].

Ergonomski dobro oblikovana sjedala osigurat će optimalnodržanje tĳela, ugodno sjedenje, pružit će osjećaj sigurnosti i prostranostitĳekom duže vožnje. Izbor materĳala, preciznost krojenja i kvalitativnospajanje dĳelova automobilske navlake šivanjem imaju za cilj trajnostautomobilske navlake barem onoliko koliko je prosječni životni ciklusautomobila. Automobilska navlaka mora imati dimenzĳsku stabilnosti,postojanosti boje na Sunčevu svjetlost, otpornost na abrazĳu i stabilnostšava. Jedno od iznimno važnih svojstava automobilskih navlaka jestkvalitativno spajanje njezinih dĳelova, koji su često izrađeni od različitihmaterĳala s različitim svojstvima, sirovinama, debljinama, tvrdoćama i sl.Prilagodba automobilske navlake zbog sve složenĳih ergonomskiprilagođenih sjedala zahtĳeva ozbiljnĳi konstrukcĳski pristup koji rezultirasve većim brojem krojnih dĳelova koje treba spojiti. Povećava se brojšavova te se daje sve veća važnost kvaliteti šava. Danas jednaautomobilska navlaka u prosjeku ima 15 krojnih dĳelova za šivanje sduljinom šava oko 25 m, dok po jednom automobilu u prosjeku ima 120krojnih dĳelova ukupne duljine šava oko 175 m. Različitost materĳala koji seupotrebljavaju za automobilske navlake (koža, skaj, tkanina, pletivo,

netkani tekstil) ne omogućuje termičko ili bilo koje drugo spajanje, osimspajanja šivanim šavom. Razlika u debljinama i komponentama tekstilnihlaminata dodatno otežava spajanje dĳelova automobilskih navlaka. Pojavanovih, mekših i podatnĳih materĳala s manjim debljinama (čupavljenjetkanine sa specĳalnim kemĳskim nanosima, kombinacĳa tkanina i netkanogtekstila s posebnim kemĳskim i mehaničkim obradama te razne prirodne iumjetne kože s dodatnim kemĳskim obradama) ide u prilog kvalitetnĳemspajanju šivanim šavom dĳelova automobilskih navlaka [1].

Nedostatci, odnosno problemi koji postoje u primjeni prirodnekože odnose se na veličinu kože i životni vĳek životinje, prirodna obilježjakoja je životinja za života dobila na koži, Slika 3. Prirodna koža različite jeveličine i nepravilnog oblika. Prĳe krojenja provodi se kontrola kvalitetekože te obilježavanje pogrešaka, Slika 4.

Slika 4. Obilježavanje pogrešaka na koži i prikaz krojne slike [8]

Nakon obilježavanja pogrešaka na koži slaže se krojna slika. Kodkrojenja je potrebna iznimna preciznost, Slika 5. Ako se previdi oštećenjena koži, primjerice, od uboda insekta to će poslĳe znatno skratiti vĳektrajanja automobilske navlake [8].

Otpornost napropuštanje vode Žilavost Mekoća Dišljivost Otpornost na

plĳesanPrirodna koža ++ ++ ++ + DaPolycotton Drill + ++ ++ ++ DaSpancer Mesh + + + +++ DaVelur + + +++ + DaNeoprene (Neosupreme) ++ + ++ + DaNeoprene (Genuine) +++ ++ ++ ++ DaUmjetna koža ++ ++ + + DaAntilop + + +++ + Da

31

Slika 5. Proces krojenja kože (Gerber cutter)[9]

Jedan od nedostataka je i mĳenjanje površine kože po kvaliteti,boji i izgledu pa je vrlo teško proizvesti automobilsku navlaku jednoličnogobojenja i kvalitete. Promatrajući s drugog aspekta to može biti prednost uunikatnosti koja se cĳeni na tržištu prometala. Sukcesivnim razvrstavanjemkože mogu se dobiti najprikladnĳi tonovi kože koji će dati poseban dezenautomobilske navlake, ali to zahtĳeva poskupljenje proizvodnje, većaznanja o materĳalima, dezenima, bojama koja su aktualna na tržištu.

4. Proces spajanja automobilskih navlakašivanim šavom

Pri izradi kožnih automobilskih navlaka većina karakterističnihtehnoloških operacĳa šivanja izvodi se na univerzalnom šivaćem stroju kojišiva dvostrukim zrnčanim ubodom tipa 301 [10]. Vrlo je važno odabrati pravitip šivaćeg šava prema standardu ISO 4916. Prema normi šivani je šav nizšivaćih uboda ili niz tipova šivaćih uboda upotrĳebljenih na jednom slojumaterĳala ili za spajanje više slojeva materĳala [11]. U Tablici 2. prikazanisu najčešće upotrebljavani tipovi šivaćih šavova kod šivanja kožnihautomobilskih navlaka.

Tablica 2. Prikaz tipova šivaćih šavova [10 – 13]

Igleni konci prema standardu označavaju se brojevima 1, 2, 3itd., dok se donji konci označavaju malim slovima a, b, c itd. [14]. Tipovišivanih šavova normirani su prema ISO 4916 [11]. Vrsta šivanog šavasastoji se od pet znamenki. Prva znamenka – skupina šivanog šava (1 – 8),druga i treća znamenka – raspored slojeva materĳala za šivanje (01 – 99),četvrta i peta znamenka – položaj uboda ili probĳanja igle (01 – 99) [14]. NaSlici 6. prikazana je kožna automobilska navlaka i interĳer luksuznogautomobila marke BMW obložen prirodnom kožom. Istaknuti sukarakteristični tipovi šavova [15 – 18].

Slika 6. Kožno automobilsko sjedalo i interĳer luksuznog automobilamarke BMW obložen prirodnom kožom [15 – 18]

Šivanje automobilskih navlaka zahtĳeva robusnĳe šivaće strojeveprilagođene šivanju debljih i višeslojnih materĳala. Stroj za šivanje treba

moći šivati materĳale različitih sirovina i debljina bez oštećenja igle, konca imaterĳala. Primjer šivaćih strojeva za šivanje kožnih automobilskih navlakatvrtke Dürkopp Adler, Slika 7. Njihova optimalna brzina šivanja jest oko2800 min-1. Mogu biti izrađeni s produženom glavom i slobodnom rukomkako bi se olakšalo rukovanje materĳalom veće površine tĳekom šivanja.

Slika 7. Šivaći strojevi namĳenjeni šivanju kožnih automobilskih navlakatvrtke Dürkopp Adler [19]

Kod šivanja kožnih automobilskih sjedala najčešće seupotrebljava dvostruka pritisna nožica. Sastoji se od vanjske pritisne nožicekoja služi pridržavanju materĳala i unutarnje pritisne nožice koja pomaže utransportu materĳala, Slika 8.

Slika 8. Dvostruka pritisna nožica s izdvojenim dĳelovima tvrtke DürkoppAdler [20]

Svi tehnološki parametri šivanja koji utječu na kvalitetu šavatrebaju se međusobno uskladiti, počevši od materĳala koji se šiva, konca,brzine šivanja, posmika materĳala, opremljenosti stroja i vrste igala.Materĳal, igla i konac za šivanje čine jedinstvenu skupinu koja izravnoutječe na kvalitetu šava. Svaki segment gornjega konca prođe 25 do 60puta kroz ušicu igle dok se ne dovede u kontakt s donjim koncem i ušĳe umaterĳal. Posebna pozornost pridaje se šivaćoj igli, odnosno vrhu igle,površinskoj obradi i materĳalu koji je na površini igle. Igla treba imati iodređenu tvrdoću te dobru toplinsku vodljivost kako bi se što manje oštetiomaterĳal na mjestu uboda i pravilno oblikovao šav. Za šivanje kožnihautomobilskih navlaka po pravilu se upotrebljavaju igle s vrhovimanamĳenjene sječenju kože. Na taj način smanjuje se trenje i olakšavaprolazak konca kroz kožu. Poprečni presjek vrha igle nĳe okrugao, već jenajčešće elipsastog ili trokutastog oblika, Slika 9. [1, 21].

Slika 9. Vrste vrhova strojnih šivaćih igala za šivanje kože [21]

Ovisno o vrsti i debljini materĳala te potrebnoj čvrstoći šavaodabire se duljina i vrsta uboda, finoća konca i vrsta igle. Svojstva konca zašivanje automobilskih navlaka najčešće su slĳedeća finoća: 50 – 105 tex,čvrstoća: 40 – 80 cN/tex, prekidno istezanje: 20 – 30 %, modul elastičnosti:0.5 – 4 cN/tex, sirovinski sastav: poliester, poliamid [22].

5. ZaključakTehnološki proces šivanja kožnih automobilskih navlaka jest

zahtjevan i složen proces. Potrebno je dobro uskladiti sve parametre utehnološkom procesu šivanja kako bi se postigla zadovoljavajuća kvalitetašava. Pogreške kod šivanja kože nisu dopuštene, bilo da je rĳeč o zaostalimoštećenjima na koži ili oštećenjima prilikom šivanja. Kožne automobilske

32

navlake i kožni interĳer automobila luksuz su koji zahtĳeva iznimnu kontroluprĳe krojenja, šivanja i postavljanja u automobil. Prirodna koža sadržavamnoga zaostala obilježja koja nĳe moguće otkloniti pa imaju važnu ulogu uprocjeni kvalitete i iskoristivosti kože. Mogu predstavljati greške koje trebaizbjeći u krojenju, ali neka obilježja koja zadovoljavaju potrebnim svojstvimamogu dati izvornost i neponovljivost automobilskih navlaka, u konačnici icjelokupnom interĳeru automobila daje unikatni luksuzni izgled koji seiznimno cĳeni u automobilskoj industrĳi.

Literatura

1. https://www.olx.ua/obyavlenie/naturalnaya-kozha-kreyzi-horscrazy-horse-krs-IDB2HDd.html, Pristupljeno: 2019-09-22

2. Kovačević, S.; Ujević, D. 2013. Seams in car seat coverings:properties and performance, Joining Textiles. Chapter No.: 16, I.Jones, G.K. Stylios (ed.), Oxford, Cambridge, UK: WoodheadPublishing Ltd, 478-506, DOI: 10.1533/9780857093967.4.478, ISBN:078-1-84569-627-6.

3. https://edutorij.e-skole.hr/share/proxy/alfresconoauth/edutorij/api/proxy-guest/ b52a40b8 3b f7-4d5c-bb15-65a258050885/biologija-8/m01/j03/index.html, Pristupljeno:2019-10-05

4. Mužic, M.; Hitrec, P. 2004. Preradba životinjske kože. Hrvatskaenciklopedija. Sv. 6: Kn – Mak; Zagreb: Leksikografski zavod MiroslavKrleža, str. 216 – 216; ISBN 953-6036-36-3.

5. https://www.leathersatchel.com/guides/care-guide/natural-leather-markings/, Pristupljeno: 2019-09-30

6. https://www.coverking.com/water-resistant-neoprene-seat-cover.html,Pristupljeno: 2019-09-30

7. https://www.wollsdorf.com/w/hr/our_leather/production/, Pristupljeno:2019-09-26

8. https://www.crlaine.com/media/wysiwyg/cms/ understanding-natural-leather/leather-bottom.jpg, Pristupljeno: 2019-09-29

9. https://www.boxmark.com/cutting_143.htm, Pristupljeno: 2019-09-26

10. ISO 4915:1991 Textiles — Stitch types — Classification andterminology

11. ISO 4916:1991 Textiles -- Seam types -- Classifi cation andterminology

12. https://www.slideshare.net/umailsushant/stitch-type-thread-consumption, Pristupljeno: 2019-09-20

13. https://www.academia.edu/10367446/type_of_stitches, Pristupljeno:2019-09-26

14. Rogale D. i sur. 2011. Procesi proizvodnje odjeće. Zagreb, Tekstilno-tehnološki fakultet.

15. https://www.pinterest.com/pin/ 292452569524253710/?nic=1,Pristupljeno: 2019-09-30

16. https://www.pinterest.com/pin/292452569524253735/, Pristupljeno:2019-09-30

17. http://www.thehogring.com/2013/08/09/intersecting-2-french-seams/,Pristupljeno: 2019-09-30

18. https://www.crowworks.com/upholstery/flat-felled-seam-1/,Pristupljeno: 2019-09-30

19. https://www.youtube.com/watch?v=pjFsukk6mO4, Pristupljeno: 2019-09-28

20. https://www.images-na.ssl-images-amazon.com/images/I/31fd%2BIXu-YL.jpg, Pristupljeno: 2019-09-28

21. https://leatherworker.net/forum/uploads/monthly_2017_03/58cae0c134520_LeatherNeedlePointsG-B.jpg.3ec6a76cf559cdcb9941135ebb7cdc97.jpg, Pristupljeno: 2019-09-30

22. Ujević, D. et al. 2002. Impact of Joined Place on the Fabric Intendedfor Manufacturing Car Seat Covers. 2nd AUTEX Conference, Bruges,Belgium, 1-3 July.

33

Natural leather car upholstery – characteristics and sewing challenges

Ph. D. Beti Rogina-Car, Ph. D. Stana Kovačević, Prof.University of Zagreb Faculty of Textile Technology

E-mail: [email protected]

AbstractThis paper gives an overview of materials and specifics in production of upholstery for vehicles. Special attention has been paid to natural leather as oneof the most luxurious materials for the manufacture of car interior upholstery materials. Its properties, advantages and disadvantages are compared withtextile materials. The quality of suitable seams is one of the most challenging tasks in making upholstery. In this paper, special emphasis is placed on cuttingand sewing natural leather used for making car interior upholstery. Natural leather is a specific natural material that gives a touch of luxury to car seats andinteriors. Durability, high price and lower market offer of leather lead to its restricted use for car upholstery compared to textile materials; however, thesereasons in particular make it extremely desirable at the same time. According to previous research, cutting and sewing of leather car upholstery requiregreater attention also when choosing the appropriate leather, sewing machine, thread, needle and seam type, which will give satisfactory properties of thecar upholstery in all segments. The purpose of this paper is to contribute to professional knowledge and specifics related to natural leather, its use for carseats and the proper quality of the sewn seam.

Keywordsnatural leather, car upholstery, properties of natural leather, sewn seam.

1. IntroductionMaterials used to make car interior upholstery for vehicles are

made of different materials by employing various technological processes.Natural leather is one of the most expensive, but also the most desirablematerials used for seat upholstery and car interior. With its exceptionallybeautiful and luxurious appearance, it attracts the customer and contributesto their decision to buy the car, Fig. 1.

Figure 1. Natural leather [1]

Extremely strong natural animal skins of bulls, cows, calves,horses, pigs, goats and sheep are used to make leather car upholstery.Leather is a very durable and resistant material, but at the same time elasticand breathable. Positive properties of natural leather are high strength,elasticity, abrasion resistance, good air permeability, softness andsmoothness. Due to its high price and exceptionally good properties,genuine leather is mainly used in more expensive cars in which thecustomer wants to have special and original interior [2].

2. Properties of natural leatherAnimal skin processing belongs to the oldest human activities.

The notes on the Babylonian clay tablets dating from 1250 BC confirm this.Humankind has been using animal skin since ancient times for protection

against external influences, attacks of other humans and animals, Fig. 2. [3,4].

Figure 2. Neanderthal, Krapina [3]

Over time, the skin dried and became hard. It began to rot anddecompose when exposed to moisture. The tanning process of animalskins gives them the necessary durability. The first tanning procedures wereperformed with animal brain mass and fats, as well as smoking. Today, thetanning process is carried out in rotating barrels for 10 to 12 hours. Tanningagents can be inorganic salts, such as chromium, aluminum, and zirconiumor vegetable tanning agents, i.e. extracts of some tropical and subtropicalplants. The use of tanning agents allows the crosslinking of collagen fibers,keeping the leather soft, elastic and stronger, more resistant to rotting andless water permeable, etc.

Leather is divided by origin into natural and artificial leather;according to the natural source, it can be bovine, calf, sheep, goat, pig,horse, alligator, snakeskin, etc.; according to the purpose, it can beclassified as leather for footwear, clothing, fancy goods, automotive andaerospace industry, and for the furniture industry, etc. [4]. The appearanceand quality of natural leather is influenced by the living conditions in whichthe animal was raised. Traces on the skin are caused by insect bites,wounds, scars, veins, wrinkles, brand marks, etc., Fig. 3. [5]

Professional PaperUDK: 675.14.017:629.3.04

34

Figure 3. Traces - natural characteristics on animal skin [5]

Properties of natural leather which are important in theautomotive industry for car interior upholstery materials are abrasionresistance, mold resistance, resistance to long and cyclic stresses,elasticity, strength, shape stability, softness and comfort when in contactwith the body, breathability, non-fraying selvages and easy care [1]. Table 1gives the comparison of the properties of some materials used to make carupholstery [6].

Table 1. Comparison of the materials used as car upholstery [6]

+ Good; ++ Better; +++ Best

Table 1 reveals that natural leather in comparison to othermaterials shows very good properties. A great difference in properties isobservable when compared to suede. The reason for this difference inproperties lies in the fact that suede is made from lower layers of animalskin, which is softer but more sensitive to other influences.

3. Natural leather car upholsteryAn example of good practice is Wollsdorf Leather, a company

that specializes in the production of leather for the automotive, aerospaceand furniture industry. It is the leader in tanning natural leather withoutchromium. The company uses high-quality bovine leather, originatingmainly from the Central European region [7]. Ergonomically well-designedseats ensure optimal body posture, comfortable seating, a sense of safetyand spaciousness during long driving hours. Material selection, precisecutting and high quality making up of car upholstery cutting parts by sewingshould ensure the durability of the car upholstery for at least the duration ofan average car lifecycle. Car upholstery should have dimensional stability,color fastness to sunlight, abrasion resistance and seam stability. One ofthe most important properties of car upholstery results from proper makingup of its parts, which are often made of different materials with differentproperties, different raw materials of varying thicknesses, harnesses, etc.Car upholstery adaptation due to increasingly complex ergonomicallyadjusted seats requires a more serious structural approach that results inan increasing number of cutting parts to be joined. The number of stitchesincreases and greater importance is attached to seam quality. Acontemporary piece of car upholstery contains an average of 15 cuttingpieces sewn with a seam length of about 25 m, whereas each car has anaverage of 120 pieces with a total seam length of about 175 m. A variety ofmaterials used for making car upholstery (natural leather, artificial leather,woven, knitted and non-woven fabrics) do not allow for thermal or any othermaking up technique other than sewing. The difference in thickness andcomponents of textile laminates further complicates the joining of carupholstery cutting parts. The emergence of new, softer and more refinedmaterials with lower thickness (napped fabrics with special chemicalcoatings, a combination of fabrics and non-woven textiles with specialchemical and mechanical treatments, and various natural and artificialleathers with additional chemical treatments) favors high-quality seamjoining of car upholstery cutting parts [1].

The disadvantages or problems that are present in the use ofnatural leather are related to the size of animal skin and animal lifecycle, aswell as the natural features that developed on the animal skin in the courseof life, Fig. 3. Natural leather is of different size and irregular shape. Leatherquality control and defect marking are performed before cutting, Fig. 4.

Figure 4. Leather defect marking and marker representation [8]

A marker is composed after marking defects on leather. Cuttingrequires extreme precision. If a damage on leather, e.g. from an insect biteis overlooked, it will later significantly shorten the lifecycle of car upholstery,Fig. 5. [8].

Figure 5. Leather cutting process (Gerber cutter) [9]

One of the shortcomings is the change of leather surface inquality, color and appearance. Therefore, it is very difficult to make carupholstery of uniform coloration and quality. From another point of view, thiscan be an advantage in the uniqueness that is appreciated on the market.Successive sorting of leather makes it possible to obtain the mostappropriate leather shades that will give a special car upholstery design, butthis requires an escalation of production prices, as well as morecomprehensive knowledge of materials, patterns and colors currentlyavailable on the market.

4. Making up process of car upholsterywith a sewn seam

In the manufacture of leather car upholstery, the mostcharacteristic technological operations of sewing are performed on auniversal sewing machine using double lockstitch type 301 [10]. Accordingto the standard ISO 4916, it is very important to choose the right type of

Water Resistance Toughness Soft Touch Breathability Mildew ResistantLeather ++ ++ ++ + YesPolycotton Drill + ++ ++ ++ YesSpancer Mesh + + + +++ YesVelour + + +++ + YesNeoprene (Neosupreme) ++ + ++ + YesNeoprene (Genuine) +++ ++ ++ ++ YesLeatherette ++ ++ + + YesSuede + + +++ + Yes

35

sewing stitch. According to the standard, a sewn seam is a series of sewingstitches or a series of types of sewing stitches used on a single materiallayer or for joining multiple material layers [11]. Table 2 shows the mostcommonly used types of sewing stitches used to sew leather car upholstery.

Table 2. Types of sewing stitches and seams [10-13]

According to the standard, needle threads are numbered 1, 2, 3etc., while bottom threads are denoted in lowercase a, b, c etc. [14]. Seamtypes are standardized according to the ISO 4916 standard [11]. Seam typeconsists of five digits. The first digit represents the seam class (1 – 8), thesecond and third digits represent the arrangement of the sewing materiallayers (01 – 99), the fourth and fifth digits represent the position of the stitchor needle penetration (01 – 99) [14]. Figure 6 shows leather car upholsteryand the interior of a BMW car in natural leather. The characteristic seamtypes are highlighted [15-18].

Figure 6. Leather car seat and interior of a BMW luxury car covered withnatural leather [15-18]

Sewing car upholstery requires more robust sewing machinesadapted to sewing thicker and multi-layered materials. The sewing machineshould be able to sew materials of different raw material content andthicknesses without damaging the needle, thread and material. An exampleof a car upholstery sewing machine produced by Dürkopp Adler is shown inFig. 7. Its optimal sewing speed amounts to about 2800 min-1. Thesemachines can be made with extended head and free arm to facilitate thehandling of a larger surface material during sewing.

Figure 7. Dürkopp Adler sewing machines for sewing leather carupholstery [19]

The double presser foot is most commonly used for sewingleather-upholstered car seats. It consists of the external presser foot thatholds the material and the internal presser foot that helps transport thematerial, Fig. 8.

Figure 8. Dürkopp Adler double presser foot [20]

All the technological parameters of sewing that affect the seamquality should be harmonized, starting with the sewing material, sewingthread, sewing speed, material feed, machine equipment and needle type.Material, needle and sewing thread form a unique group that directly affectsseam quality. Each segment of the upper thread passes 25 to 60 timesthrough the needle eye until it comes into contact with the lower thread andis finally sewn into the material. Special attention should be paid to thesewing needle, namely to the needlepoint, surface treatment and thematerial that is on the surface of the needle. The needle should also haveadequate hardness and good thermal conductivity to minimize damage tothe material at the penetration site and to properly form a seam. Needleswith cutting points for cutting leather are most commonly used for sewingleather car upholstery. This reduces friction and facilitates the passage ofthe thread through the leather. The cross section of the needlepoint is notround, but usually elliptical or triangular, Fig. 9. [1, 21].

Figure 9. Needlepoint types of machine sewing needles for sewing leather[21]

The length and type of stitches, thread fineness and needle typeare selected depending on the type and thickness of the material and thenecessary seam strength. The properties of sewing thread for sewing carupholstery are usually the following: thread count: 50-105 tex, strength: 40-80 cN/tex, elongation at break: 20-30%, modulus of elasticity: 0.5-4 cN/tex,raw material composition: polyester, polyamide [22].

5. ConclusionThe technological process of sewing leather car upholstery is a

demanding and complex process. It is necessary to harmonize all theparameters in the technological sewing process in order to achieve asatisfactory seam quality. Defects when sewing leather are not tolerated,whether they occur as residual leather damage or sewing damage. Leathercar upholstery and leather interior of the car represent luxury, requiringexceptional control before cutting, sewing and installing. Natural leathercontains many residual features that cannot be eliminated, so they play animportant role in assessing the quality and utilization of leather. They mayrepresent defects to be avoided in cutting. However, some features thatsatisfy the required properties can provide originality and uniqueness of carupholstery materials. Moreover, they give the entire car interior a uniqueluxury appearance that is highly valued in the automotive industry.

Literature

1. https://www.olx.ua/obyavlenie/naturalnaya-kozha-kreyzi-horscrazy-horse-krs-IDB2HDd.html, Accessed:2019-09-22

2. Kovačević S., Ujević D.: Seams in car seat coverings: properties andperformance, Joining Textiles, Chapter No.: 16, I. Jones, G.K. Stylios(ed.), Oxford, Cambridge, UK: Woodhead Publishing Ltd, 2013., 478-506, DOI: 10.1533/9780857093967.4.478, ISBN: 078-1-84569-627-6.

3. https://edutorij.e-skole.hr/share/proxy/alfresco-noauth/edutorij/api/proxy-guest/b52a40b8 3b f7-4d5c-bb15-65a258050885/biologija-8/m01/j03/index.html, Accessed:2019-10-05

4. Mužic, M., Hitrec, P.: Preradba životinjske kože. Hrvatskaenciklopedija. Sv. 6: Kn - Mak; Zagreb: Leksikografski zavod MiroslavKrleža, str. 216-216; ISBN 953-6036-36-3, 2004.

5. https://www.leathersatchel.com/guides/care-guide/natural-leather-

36

markings/, Accessed:2019 -09-30

6. https://www.coverking.com/water-resistant-neoprene-seat-cover.html,Accessed: 2019-09-30

7. https://www.wollsdorf.com/w/hr/our_leather/production/,Accessed:2019-09-26

8. https://www.crlaine.com/media/ wysiwyg/cms/understanding-natural-leather/leather-bottom.jpg, Accessed:2019-09-29

9. https://www.boxmark.com/cutting_143.htm, Accessed:2019-09-26

10. ISO 4915:1991 Textiles — Stitch types — Classification andterminology

11. ISO 4916:1991 Textiles -- Seam types -- Classification andterminology

12. https://www.slideshare.net/umailsushant/stitch-type-thread-consumption, Accessed:2019-09-20

13. https://www.academia.edu/10367446/type_of_stitches,Accessed:2019-09-26

14. Rogale D. i sur.: Procesi proizvodnje odjeće, Zagreb, Tekstilno-tehnološki fakultet, 2011.

15. https://www.pinterest.com/pin/ 292452569524253710/?nic=1,Accessed:2019-09-30

16. https://www.pinterest.com/pin/292452569524253735/,Accessed:2019-09-30

17. http://www.thehogring.com/2013/08/09/intersecting-2-french-seams/,Accessed:2019-09-30

18. https://www.crowworks.com/upholstery/flat-felled-seam-1/,Accessed:2019-09-30

19. https://www.youtube.com/watch?v=pjFsukk6mO4, Accessed:2019-09-28

20. https://www.images-na.ssl-images-amazon.com/images/I/31fd%2BIXu-YL.jpg, Accessed:2019-09-28

21. https://leatherworker.net/forum/uploads/monthly_2017_03/58cae0c134520_LeatherNeedlePointsG-B.jpg.3ec6a76cf559cdcb9941135ebb7cdc97.jpg, Accessed: 2019-09-30

22. Ujević, D. et al.: Impact of Joined Place on the Fabric Intended forManufacturing Car Seat Covers“, 2nd AUTEX Conference, Bruges,Belgium, 1-3 July, 2002.

37

Obilježena 140. godišnjica tekstilne stručne škole

Š kola za modu i dizajn u svibnju ove godine, obilježila je 140 godinaškolovanja učenika i učenica u području tekstila od davne 1879.

godine kada je osnovana Šivaća i risačka škola pri Višoj djevojačkoj školi.

Slavlje se odvilo pod visokim pokroviteljstvom Grada Zagreba idomaćinstvom Obrtničke komore Zagreb. Djelatnici škole na čelu s v. d.ravnateljicom Majom Dadić Žeravicom i učenicima prikazali su bogatiškolski život i dinamiku strukovnih zanimanja tĳekom modne revĳe odosam modnih kolekcĳa od kojih su dvĳe predstavljale inovacĳe u tekstilu –Šestinski kišobran u novom ruhu: kao torba, ruksak ili prostirka za plažu iKombucha moda gdje su uzgojem bakterĳske kulture u kontroliranimuvjetima školskog laboratorĳa, izrađeni elementi na haljini. Posebice subili ponosni na nagrađene kolekcĳe s ovogodišnjeg natjecanja WorldSkillsCroatia koju su nazvali Bajke iz Škole za modu i dizajn budući da suinspirirane bajkama Ivane Brlić Mažuranić.

Cĳeli događaj je glazbeno popratio Školski bend Škole za modui dizajn i Upravne škole Zagreb. Skupu su prisustvovali visoki gosti iuzvanici iz svĳeta obrazovanja od kojih se istaknuo gosp Vlado Prskalo,pomoćnik ministrice znanosti i obrazovanja, gosp. Ivica Lovrić pročelnikGradskog ureda za obrazovanje i gosp. Mile Živčić, ravnatelj Agencĳe zastrukovno obrazovanje i obrazovanje odraslih. Također, podršku su pružili

članovi Hrvatske obrtničke komore, Hrvatske gospodarske komore,Udruženja obrtnika grada Zagreba, ugledni direktori hrvatskih tvrtki,ravnatelji zagrebačkih srednjih i osnovnih škola te renomirani hrvatskidizajneri na koje su djelatnici posebno ponosni jer su mnogi od njih upravonjihovi bivši učenici poput Aleksandre Dojčinović, Ivana Tandarića, MarĳeKulušić, Martine Felje i Anite Zannotti Štulec.

Vjerujemo da će se ova škola razvĳati i dalje u jednu dinamičnui modernu srednju strukovnu školu koja uspješno odgovara potrebamatržišta.

38

www.hdko.hr

Documents

VOLUMEN 68 BROJ 2/19¾a-Obuća-br-2-2019-1.2.pdf · Tradicionalne metode determiniranja morfologĳe stopala u svojem opsegu uzimanja mjera nisu dovoljne da točno definiraju oblik