Footwear AssessmentFootwear Assessment

Ken Wong (OT)Ken Wong (OT)Price of Wales Hospital Price of Wales Hospital

IntroductionIntroductionFall risk factorsFall risk factors

•• Intrinsic factorsIntrinsic factors–– Poor lower limb Poor lower limb proprioceptionproprioception–– Visual impairmentVisual impairment–– Decreased reaction timeDecreased reaction time–– Decreased lower limb muscle strength etc.Decreased lower limb muscle strength etc.

•• ExtrinsicsExtrinsics factors factors ((MenzMenz HB et al. 2000)HB et al. 2000)–– Environmental hazards (insufficient lighting, poor Environmental hazards (insufficient lighting, poor

housekeeping etc.)housekeeping etc.)–– Unsafe footwearUnsafe footwear

•• Footwear is a potentially modifiable factor that Footwear is a potentially modifiable factor that play a role in some falls play a role in some falls (Thomson et al. 2004) (Thomson et al. 2004)

•• Inappropriate footwear has been contributed to Inappropriate footwear has been contributed to 45% of falls45% of falls ((MenantMenant J. C. 2008)J. C. 2008)

•• Shoes alter the interface between the foot and Shoes alter the interface between the foot and the groundthe ground ((MenzMenz HB et al., 1999)HB et al., 1999)

Fall (slip / trip)Fall (slip / trip)•• SlipSlip

–– a a sudden loss of gripsudden loss of grip, in the presence of liquid , in the presence of liquid or solid contaminantsor solid contaminants

–– results in results in sliding of the footsliding of the foot on a surface on a surface

•• Trip Trip –– sudden interruptionsudden interruption of the of the

foot in the swing phase by foot in the swing phase by uneven surfaces or with uneven surfaces or with obstaclesobstacles on the flooron the floor

((GronqvistGronqvist Q et al. 2001)Q et al. 2001)

Fall mechanismFall mechanism

•• Forward falls / lateral Forward falls / lateral falls (less common)falls (less common)

•• Backward falls involve Backward falls involve pelvic impact due to pelvic impact due to slipping after heel slipping after heel contact (most common)contact (most common)

A conceptual framework of a foot slide A conceptual framework of a foot slide leading to backward fallleading to backward fall

••((GronqvistGronqvist Q et al. 2001)Q et al. 2001)

Center of mass (COM)

Base of support (BOS)

•• Heel contact and toeHeel contact and toe--offoff•• Heel contact phase is more challenging for Heel contact phase is more challenging for

stability, as the stability, as the forward momentumforward momentum maintains maintains the body weight on the leading foot causing a the body weight on the leading foot causing a forward slide of foot forward slide of foot ((RedfernRedfern et a. 2001)et a. 2001)

Front and rear part of sole in contract

Heel contact

Two critical gait momentTwo critical gait moment

•• Interaction between an Interaction between an elastic elastic shoe soleshoe sole, an , an interfacial interfacial contaminantcontaminant and and the the floor surface.floor surface.

•• Preventing slip, Preventing slip, resisting resisting friction forcefriction force should be should be higher than the horizontalhigher than the horizontalcomponent of the component of the force force ((GronqvistGronqvist Q et al. 2001)Q et al. 2001)

FF

FF

V

H

N

uu >=

Friction CoefficientFriction Coefficient

((GronqvistGronqvist Q et al. 2001)Q et al. 2001)

Friction CoefficientFriction Coefficient

•• Excessive slip resistance of shoe may lead Excessive slip resistance of shoe may lead to fallto fall–– when pivoting the upper body to perform a when pivoting the upper body to perform a

ADL tasks, friction between the shoe and the ADL tasks, friction between the shoe and the contact surface restricted the feet from pivot, contact surface restricted the feet from pivot, resulting in loss of balance resulting in loss of balance (Connell BR, 1997)(Connell BR, 1997)

–– UncommonUncommon

How to select an appropriate footwear?How to select an appropriate footwear?

Boot

Slipper

Clog

Sandal

Oxford

MoccasinMoccasin

Athletic shoeAthletic shoe Canvas shoeCanvas shoe

Old people shoeOld people shoe

Features of footwearFeatures of footwear

Features of shoe design that have an Features of shoe design that have an impact on balanceimpact on balance

–– Heel heightHeel height–– HeelHeel--collar height collar height –– HeelHeel--collar stiffnesscollar stiffness–– Sole hardnessSole hardness–– BevelledBevelled heelheel–– Slip resistance of the outer sole Slip resistance of the outer sole –– Sole geometrySole geometry–– FixationFixation

Heel heightHeel height

•• High heel shoe (4.5cm) impaired balanceHigh heel shoe (4.5cm) impaired balance

–– Heel elevation shifts the body COM Heel elevation shifts the body COM anteriorlyanteriorly, , modifying posture and plantar pressure distribution.modifying posture and plantar pressure distribution.

–– Lead to lateral instability because of a smaller critical Lead to lateral instability because of a smaller critical tipping angle compared to lower heel shoestipping angle compared to lower heel shoes

Collar HeightCollar Height

•• High collar High collar •• low collar low collar

–– Circumferential ankle pressure (tactile Circumferential ankle pressure (tactile stimulus) stimulus) •• enhances joint position senseenhances joint position sense•• improve stabilityimprove stability

Robbins SE, 1995

Heel collar stiffnessHeel collar stiffness

•• Stiff heel collar assist in controlling heel movementStiff heel collar assist in controlling heel movement

Sole hardnessSole hardness•• Hard / thin sole shoes Hard / thin sole shoes

Thick / soft sole shoes Thick / soft sole shoes

–– Thick soft sole shoes Thick soft sole shoes impaired joint position impaired joint position sense and balancesense and balance•• reduce transmission of tactile sensory input to the reduce transmission of tactile sensory input to the

feet and delayed CNS to respond accordingly to feet and delayed CNS to respond accordingly to control balance. control balance.

–– Cushioning properties in the midCushioning properties in the mid--sole sole attenuate normal perception of impact and attenuate normal perception of impact and prevent normal impactprevent normal impact--moderating behaviorsmoderating behaviors

A conceptual framework of a foot slide A conceptual framework of a foot slide leading to backward fallleading to backward fall

••((GronqvistGronqvist Q et al. 2001)Q et al. 2001)

Center of mass (COM)

Base of support (BOS)

BevelledBevelled heelheel

•• BevelledBevelled heel provided a heel provided a greater coefficient of greater coefficient of frictionfriction then a shoe with a squaredthen a shoe with a squared--edged heeledged heel

•• Improve slip resistance by Improve slip resistance by increasing the surface increasing the surface contact areacontact area at heel strikeat heel strike

((MenzMenz HB et al., 1999)HB et al., 1999)

Sole geometrySole geometry•• Midsole flare Midsole flare

–– difference between the width of the midsole at the level of the difference between the width of the midsole at the level of the upper and its width at the level of the outsoleupper and its width at the level of the outsole

•• A flared sole enhanced stability byA flared sole enhanced stability by–– providing a providing a larger base of supportlarger base of support -- significantly associated with significantly associated with

lower risk of falllower risk of fall (Allan F et al., 2004)(Allan F et al., 2004)

–– longer moment arm (X) for longer moment arm (X) for eversioneversion offered better base of support offered better base of support

Larger displacement needed

(Lord SR, 1994)(Lord SR, 1994)

Tread patternTread pattern

•• Wider tread grooveWider tread groove results in higher results in higher COF values COF values

•• Shoe sole with deep cleat and Shoe sole with deep cleat and well well defined tread patterndefined tread pattern can improve can improve slip resistance slip resistance

•• Linear grooves disperse fluid from Linear grooves disperse fluid from under the shoe under the shoe

•• Wear Wear flat shoesflat shoes maximize the area maximize the area of contact with the floorof contact with the floor

•• Outsole material hardness increase, Outsole material hardness increase, coefficient of friction decrease coefficient of friction decrease

((MenzMenz HB et al., 1999)HB et al., 1999)

FixationFixation

•• Shoe without proper fixation Shoe without proper fixation promote unsteady gait and promote unsteady gait and are more likely to be are more likely to be separated from the foot when separated from the foot when walkingwalking ((MenzMenz HB et al., 1999)HB et al., 1999)

•• Lace, Lace, velcrovelcro, zip, elastic lace , zip, elastic lace with popwith pop--locklock–– Velcro is easy to fastenVelcro is easy to fasten–– Lace have more room for Lace have more room for

adjustmentadjustment

Appropriate Slippers?Appropriate Slippers?

•• Similar principles and featuresSimilar principles and features•• Slipper use at home onlySlipper use at home only

Size Size –– too large / smalltoo large / small

Slide inside slipperSlide inside slipper-- sock with slippersock with slipper-- insole materialinsole material

Humidity ~ SlipperHumidity ~ Slipper

NonNon--slip soleslip sole

VS

Size of slipper cover ~ FixationSize of slipper cover ~ Fixation

Footwear selection for elderly with Footwear selection for elderly with various foot problemvarious foot problem

Hammer toesHammer toes

•• Toes are squashed by wearing poorly Toes are squashed by wearing poorly fitting shoes for long time or high heelfitting shoes for long time or high heel

–– Toe boxesToe boxes•• SoftSoft•• spacious with sufficient width and height spacious with sufficient width and height

–– A A harder shoe soleharder shoe solereduce painful reduce painful dorsiflexiondorsiflexionat the first MTP jointat the first MTP joint

HalluxHallux ValgusValgus•• If shoes press against the bunion. The If shoes press against the bunion. The

bursa may become inflamed and painful bursa may become inflamed and painful

–– Choosing shoes with a Choosing shoes with a soft upper soft upper and medial coverand medial cover will reduce will reduce pressure and friction on the bunionpressure and friction on the bunion

–– Avoid oversized shoeAvoid oversized shoe•• prevent foot slide with rubbing on prevent foot slide with rubbing on

the bunionthe bunion

Diabetic footDiabetic foot

•• Footwear has been implicated as an extrinsic Footwear has been implicated as an extrinsic cause of foot ulcers in people with diabetes cause of foot ulcers in people with diabetes (Gayle E et al. 2002).(Gayle E et al. 2002).

•• Footwear must be Footwear must be smooth on the insidesmooth on the inside•• Individuals with sensation loss tend to buy shoes Individuals with sensation loss tend to buy shoes

that are too small because they can feel the that are too small because they can feel the shoe in fittingshoe in fitting

•• Do wear sock to fit shoeDo wear sock to fit shoe

Point to note when selecting shoePoint to note when selecting shoe•• UpperUpper

–– Soft, flexible and ideally waterproofSoft, flexible and ideally waterproof–– A smooth liningA smooth lining

•• Toe boxToe box–– Should be deep enough to allow you to wriggle your Should be deep enough to allow you to wriggle your

toetoe•• SoleSole

–– Strong and flexible for good gripStrong and flexible for good grip•• HeelHeel

–– Broad base for stabilityBroad base for stability–– Should be no higher than 4cmShould be no higher than 4cm

•• FasteningFastening–– Provide stable fit and some flexibility to allow for Provide stable fit and some flexibility to allow for

unusually shaped feet or swellingunusually shaped feet or swelling•• Try shopping for shoes later in the afternoonTry shopping for shoes later in the afternoon

Perception of elderly towards footwearPerception of elderly towards footwear

•• Oversea surveyOversea survey•• Older people based their footwear choice on Older people based their footwear choice on

comfort rather than safetycomfort rather than safety (Catherine, 2003)(Catherine, 2003)

•• In a survey of 147 subjects with fall history In a survey of 147 subjects with fall history ––73% reported that comfort, not safety was the 73% reported that comfort, not safety was the primary concernprimary concern ((MenzMenz HB et al. 1999)HB et al. 1999)

A survey on footwear among patient A survey on footwear among patient with history of fall in PWHwith history of fall in PWH

•• Local surveyLocal survey•• Selection criteriaSelection criteria

–– 68% price 68% price –– 54% non54% non--slippery performanceslippery performance–– 31% outlook31% outlook

•• 40% able to report at least 3 criteria of an appropriate 40% able to report at least 3 criteria of an appropriate footwearfootwear

•• 27% able to select an appropriate footwear in 3 demo. 27% able to select an appropriate footwear in 3 demo. shoeshoe

ConclusionConclusion

•• Inappropriate footwear is a risk factor of Inappropriate footwear is a risk factor of elderly fallelderly fall

•• Footwear is a potentially modifiable factor Footwear is a potentially modifiable factor that play a role in some fallsthat play a role in some falls

•• Education on the selection of appropriate Education on the selection of appropriate footwear should be a part of fall footwear should be a part of fall prevention program prevention program

The EndThe EndThank youThank you

ReferenceReference

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•• Thomas D et al. 2004, Footwear style and risk of falls in older Thomas D et al. 2004, Footwear style and risk of falls in older adults. JAGS, 52:1495adults. JAGS, 52:1495--1501. 1501. •• Gayle E et al. 2002, Footwear used by individuals with diabetes Gayle E et al. 2002, Footwear used by individuals with diabetes and a history of foot ulcer. and a history of foot ulcer.

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131131•• MenzMenz HB et al. 2000, The Footwear Assessment Form: a reliable clinicHB et al. 2000, The Footwear Assessment Form: a reliable clinical tool to assess footwear al tool to assess footwear

characteristics of relevance to postural stability in older adulcharacteristics of relevance to postural stability in older adults. Clinical Rehabilitation, 14: 657ts. Clinical Rehabilitation, 14: 657--664664•• Allan F et al. 2004, Biomechanical Properties of Shoes and Risk Allan F et al. 2004, Biomechanical Properties of Shoes and Risk of Falls in Older Adults. JAGS 52: of Falls in Older Adults. JAGS 52:

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