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118 Abstracts / Journal of Science an

he dependent variable. Boys and girls were analysed sepa-ately.

Results: Fitness performance varied with weight statuscross all fitness tests (p < 0.001). Jumping performanceended to decline as weight status increased, except in thetanding broad jump where thin boys performed worse thanheir normal weight peers. For sprint and endurance running,he very thin, thin and normal weight youths displayed sim-lar performances, with progressively poorer performancesbserved for overweight and obese youths respectively. Forndurance running performance, distinct sex differences werepparent, with the very thin and thin boys performing moreoorly, and the very thin and thin girls performing better thanheir normal weight peers.

Conclusions: Contrary to expectations, the thin youngeople performed well compared to their peers. The fitness-erformance of thin youth was broadly similar to that oformal weight youth and significantly better than obeseouth. Weight status affects both the supply and demandomponents of fitness performance. Therefore, the factorsssociated with thinness (e.g. reduced fat, muscle and bodyass) may account for the positive performances of thin

outh when compared to those from other weight statuses.iven these findings, no specific health-related fitness inter-entions are indicated for thin Australian youth.

oi:10.1016/j.jsams.2009.10.242

42

assing and goal scoring characteristics in the Australian-League

. Johnson ∗, A. Murphy

University of Technology, Sydney

Introduction: The global development of football and itsncreasing level of professionalism has lead to a greateremand for detailed information regarding all aspects oferformance. Nonetheless, very little is known regardinguccessful strategies and tactics in Australian Football. Theajor aim of the current study was to determine if shorter

assing sequences (four or less passes) are a more effectiveethod of scoring goals than longer passing sequences (more

han five passes).Methodology: Data regarding the number of passes per

ossession were collected on all regular season matches dur-ng the 2007–2008 A-League Association Football (soccer)ompetition. Eighty four matches were coded by Sportsdataty Ltd ©using a computerised video analysis system, Theootball Analyst (Analyzer - SDSF 70654 V4.01.510).

Results: A total 49662 possessions were analysed, result-

ng in 220 goals. A higher proportion of goals are scored fromonger passing sequences producing an average of 13 goalser 1000 possessions compared to 6 goals per 1000 posses-ions from shorter passing sequences. Notably, 46% of team

ottw

cine in Sport 12 (2010) e1–e232

ossessions were zero length passing possessions. This per-entage is considerably higher than the figure reported inxisting literature (approximately 25%).

Conclusions: The current study found that longer passingequences are a more efficient way of scoring goals comparedo shorter passing sequences in elite Australian football. Theigher percentage of zero length possessions could be a resultf different football styles, a lower perceived value of retain-ng possession of the ball and/or a lower skill level of players,esulting in an inability to control the ball and maintain pos-ession. This information can be utilised by coaches andlayers to identify the most successful tactics and strategiesor creating goal scoring opportunities during the 2007–2008-League season and compare the A-League competition tother national and international competitions. These resultslso highlight a requirement for A-league coaches to developraining programs designed to increase the number of passeser possession and reduce the number of zero length passingossessions.

oi:10.1016/j.jsams.2009.10.243

EFSHAUGE LECTURE

43

otational analysis: Establishing stable performance pro-les in A-League football

. Johnson, A. Murphy ∗, R. Bower

University of Technology, Sydney

Introduction: To ensure the reliability and validity of infor-ation generated via notational analysis it is important to

stablish stable performance profiles; otherwise any state-ents regarding the performance may not be valid. Previous

otational analysis studies have employed relatively smallample sizes presenting an inherent danger of producingesults that are unrepresentative of the way the team typicallylays. The aim of this study was to investigate the numberf matches required to be examined (sample size) prior tostablishing a stable performance profile for three importanterformance indicators in Australian football. Methodology:he performance indicators examined in this study included

he number of shots at goal, goals scored and passes peream per match. This data were collected on all regulareason matches during the 2007 - 2008 A-League Asso-iation Football (soccer) competition. Eighty four matchesere coded by Sportsdata Pty Ltd ©using a computerisedideo analysis system, The Football Analyst (Analyzer -DSF 70654 V4.01.510). The establishment of the stablerofiles was determined by examining the cumulative means

f each variable over consecutive matches for each team inhe competition. The first point (number of matches) wherehe cumulative mean consistently lay within set limits of erroras recorded as the establishment of a stable profile for that

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Abstracts / Journal of Science an

erformance variable. The limits of error were set as a ±5%eviation about the overall data mean. Results: The numberf matches required to be notated to achieve a stable pro-le for shots for goal ranged from 8 to 20, with an averagef 15 matches. A stable profile for the number of goals peratch was reached after analysing between 15 to 21 matches

average 18 matches). The number of matches required to beotated to achieve a stable profile for passing ranged fromto 7, with an average of 4 matches. Therefore, the num-

er of matches required to be analysed is dependent on theeam and variability of the performance indicator between

atches. Conclusion: Knowledge of the minimum numberf matches required to be notated prior to the establishmentf a stable performance profile may improve the efficiency,eliability and validity of the notation and analysis proce-ures. It is recommended that at least 16 matches are notatedrior to establishing stable performance profiles of elite Aus-ralian football teams. Moreover, studies that have reportedata on less than this number should be viewed with caution.

oi:10.1016/j.jsams.2009.10.244

EFSHAUGE LECTURE

44

usculoskeletal health of male and female apprenticeockeys

. Wyner

Australian Catholic University

Abstract: The typical jockey is small in stature and light ineight. In order to remain within specific weight limits, jock-

ys often engage in unhealthy weight-loss behaviours thately on rapid, short-term weight loss and have an increasedropensity to engage in disordered eating. Engaging in activ-ties and behaviours that restrict the attainment of peak bone

ass during growth produces deleterious musculoskeletalffects in later life. Musculoskeletal responses to prolongedemands of elite physical performance in young adults whoegularly experience energy drain from physical activity andisordered eating are relatively unknown. Delayed growth,oupled with intensive training, may predispose apprenticeockeys to repetitive microtraumatic injury to the muscu-oskeletal system. Purpose: (i) to profile the musculoskeletalealth of male and female apprentice jockeys and less active,ge- and sex- matched peers (control group). Methods: Tworoups of 25 young adults (n = 50) (age range 15 - 38 years)omprised of male and female apprentice jockeys, and malend female controls. Peripheral Quantitative Computeredomography (pQCT) was used to assess musculoskeletal

ealth of the distal tibia and distal radius. Trabecular areand density, cortical area and density, and stress strain indexas calculated. Results: After covarying for limb length andeight, apprentice jockeys displayed lesser tibial cortical area

(i2c

cine in Sport 12 (2010) e1–e232 e119

nd stress strain index at 14%, 38% and 66% sites mea-ured distally (p = 0.001). No differences between groupsere found in cortical density, trabecular area, and trabecu-

ar density at the tibia. Apprentice jockeys displayed greaterrabecular density at the ultra-distal radial site (p = 0.001)nd greater stress strain index at 66% site measured distallyp = 0.01). Control participants showed greater cortical areat 66% radial site (p = 0.03) and greater stress strain index athe ultra-distal radius (p = 0.006). Conclusions: Apprenticeockeys displayed compromised musculoskeletal health at theistal tibia and radius compared to control participants. Onlyrabecular density at the ultra-distal radius and stress strainndex at radial mid-shaft was greater in apprentice jockeys.

oi:10.1016/j.jsams.2009.10.245

45

istory of amenorrhoea compromises some of thexercise-induced benefits in trabecular bone in retiredymnasts

. Ducher 1,∗, P. Eser 2, B. Hill 1, S. Bass 1

Centre for Physical Activity and Nutrition Research, Deakinniversitydepartment of Rheumatology and Clinical Immunol-gy/Allergology, University Hospital Bern, Bern, Switzerland

Introduction: Female gymnasts frequently present withvert signs of hypoestrogenism, such as late menarche orenstrual dysfunction. The objective was to investigate the

mpact of history of amenorrhoea on the exercise-inducedkeletal benefits in bone geometry and volumetric densityn retired elite gymnasts. Methodology: 24 retired artisticymnasts, aged 17–36 years, who had been training for ateast 15 h/week at the peak of their career and had beenetired for 3–18 years were recruited. They had not beenngaged in more than 2 h per week of regular physical activ-ty since retirement. Former gymnasts who reported historyf amenorrhoea (‘AME’, n = 12: either primary or secondarymenorrhoea) were compared with former gymnasts (‘NO-ME’, n = 12) and controls (‘C’, n = 26) who did not reportistory of amenorrhoea. Primary amenorrhoea was defineds the failure to menstruate by the age of 15 years. Sec-ndary amenorrhoea was defined as the absence of mensesor 3 months or more after menarche. Bone mineral con-ent and bone size were measured by peripheral quantitativeomputed tomography (pQCT) at the radius and tibia (4%,6%), femur (4%, 25%) and humerus (25%). Trabecularolumetric density (TrD) was measured at the 4% sites.ndices of bone strength were calculated at each skeletal site.esults: AME had delayed menarche compared to NO-AME

16.4 ± 0.5 yrs vs. 13.3 ± 0.4 yrs, p < 0.001) and higher train-ng volume at the peak of their career (29.9 ± 2.1 h/week vs.1.3 ± 1.6 h/week, p < 0.01). Age at menarche was positivelyorrelated with training volume at highest level (r = 0.67,