Barefoot vs running shoes – Comparing 20m sprint performance, spatiotemporal variables and foot strike patterns in schoolchildren in the Western Cape

Murphy, Ian Desmond (2017-03)

Thesis (MScSportSc)--Stellenbosch University, 2017

Thesis

ENGLISH ABSTRACT : A short anaerobic sprint test such as a 20m sprint test forms part of many fitness test batteries used by sports teams and in schools during physical education classes for fitness testing. Some of these short sprint tests are done on a hard running surface and some of the protocols do not specify or standardise the type of footwear that should be worn and participants have a choice to sprint either barefoot (BF) or in running shoes. Similarly, many children and adolescents in South African schools participate in athletics competitions that are sometimes held on synthetic athletics tracks and since most children and adolescents do not own spikes, they have to choose between competing BF or in their running shoes. In some countries such as South Africa, which has a BF culture, sprinting BF is common. Currently, there is limited research available to answer whether it is faster to sprint BF or shod. The aim of the current study was to determine the acute effects of sprinting BF and in running shoes on 10m and 20m sprint performance, spatiotemporal variables and foot strike pattern (FSP). 115 Girls and 161 boys (N=276) aged 8-19 years from randomly selected schools in the Western Cape Province were recruited for the study. Children performed two 20m maximal effort sprints from a standing start on a hard running surface in both a BF and running shoes condition in random order. For each sprint, 10m and 20m sprint times, step frequency (StepF), stride length (SL), flight time (FT), ground contact time (GCT) and swing time (SwT) were measured and FSP was determined. Sprint times were measured with electronic photocells (Brower Timing Systems, Salt Lake City, UT) and spatiotemporal variables were measured with the OptoGait system (Microgate S.r.I, Bolzano, Italy). High-speed video footage was taken with a GoPro camera (GoPro HD Hero 4, GoPro Inc., San Mateo, California, USA) at 240Hz and was analysed with video analysis software (Kinovea 0.8.15) to determine FSPs. The data of the fastest sprint in each footwear condition was used for further statistical analysis. Statistically significant differences as well as small to medium practically significant differences were found between the BF and shod conditions for children and adolescents’ 10m and 20m sprint performance and all the measured spatiotemporal variables. When BF, children and adolescents’ 10m and 20m sprint performances were significantly faster (p<0.001) but with only small effect sizes (d=0.24 and d=0.25 respectively). The faster sprint performances when BF were due to a significantly higher StepF (p<0.001) with a medium effect size (d=0.42) despite being accompanied by a significantly shorter SL (p<0.001) with a medium effect size (d=0.73). The significantly higher StepF when BF was due to a significantly shorter FT (p=0.022) with a small effect size (d=0.16), a significantly shorter GCT (p<0.001) with a medium effect size (d=0.69) and a significantly shorter SwT (p<0.001) with a medium effect size (d=0.56). All differences in sprint performance and spatiotemporal variables were due to the shoe mass effect and not due to FSP differences caused by the footwear effect. Changing from the shod to the BF condition caused a significant decrease in the occurrence of a rearfoot strike (RFS) from 57% to 27% and a significant increase in the occurrence of a forefoot-/midfoot strike (FFS/MFS) from 43% to 73% (p<0.001). The shod condition, therefore, encouraged a significantly higher rate of RFS and the BF condition a significantly higher rate of FFS/MFS. In conclusion, changing from running shoes to BF has a significant acute effect on short anaerobic sprint performance, spatiotemporal variables and FSPs of schoolaged children. Sprinting BF is only marginally faster than sprinting in running shoes over 10m and 20m but this may potentially only be applicable to habitually BF children and adolescents. Sprinting BF or in running shoes is, therefore, almost the same speed and children and adolescents can choose either footwear condition for sprint tests of fitness batteries and for athletics competitions held on synthetic athletics tracks. Caution should be taken when acutely changing to sprinting BF since it increases the risk of plantar surface injuries.

AFRIKAANSE OPSOMMING : ‘n Kort anaërobiese naellooptoets soos die 20m naellooptoets vorm deel van baie toetsbatterye wat vir fiksheid gedurende liggaamlike opvoedingsklasse en by sportspanne gedoen word. Sommige van hierdie naellooptoetse word op harde oppervlaktes gedoen. Sommige protokolle spesifiseer of standaardiseer nie met watter tipe skoene gehardloop moet word nie en het deelnemers die keuse om kaalvoet of met skoene te hardloop. Baie kinders en adolessente in Suid Afrikaanse skole neem deel aan atletiekkompetisies wat dikwels op sintetiese bane gehou word. Aangesien die meeste kinders en adolessente nie hul eie spykerskoene het nie, moet hulle kies om kaalvoet of in hul eie hardloopskoene te hardloop. In sommige lande soos Suid Afrika, wat ‘n kaalvoetkultuur het, is naellope kaalvoet algemeen. Daar is tans beperkte navorsing beskikbaar om aan te dui of dit vinniger is om kaalvoet of in hardloopskoene te nael. Die doel van die huidige studie was om te bepaal wat die akute effek van ‘n naelloop kaalvoet (KV) en met sportskoene op 10m en 20m naelloopprestasie, tyd-ruimtelike veranderlikes en voetneersitpatrone was. 115 Meisies en 161 seuns (N=276) tussen die ouderdom 8 tot 19 jaar is genader uit lukraak verkose skole in die Wes-Kaap Provinsie. Kinders het twee 20m maksimale naellope vanuit ‘n staande wegspring op ‘n harde oppervlakte gehardloop, in beide die KV en skoenkondisie. Vir elke naelloop is die tye oor 10m en 20m geneem, en treefrekwensie (TF), treelengte (TL), vlugtyd (VT), grondkontaktyd (GKT) en swaaityd (ST) gemeet en is die voetneersitpatrone bepaal. Naellooptye is bepaal met gebruik van elektroniese spoedselle (Brower Timing Systems, Salt Lake City, UT). Tyd-ruimtelike veranderlikes is met behulp van die OptoGait sisteem gemeet (Microgate S.r.I, Bolzano, Italië). Hoë spoed videomateriaal was teen 240Hz geneem met ‘n GoPro kamera (GoPro HD Hero 4, GoPro Inc., San Mateo, Kalifornië, VSA) en is ontleed met video analise sagteware (Kinovea 0.8.15) om die voetneersitpatrone te bepaal. Die data van die vinnigste naellooptyd vir kaalvoet en met skoene is gebruik vir verdere statistiese analise. Statisties beduidende verskille, asook klein tot medium prakties beduidende verskille, is gevind tussen die KV en skoenkondisies vir kinders en adolessente se 10m en 20m naellooptye en al die tyd-ruimtelike veranderlikes. Wanneer kaalvoet, het die kinders en adolessente beduidend vinniger (p<0.001) in die 10m en 20m gehardloop, maar met slegs ‘n klein effekgrootte (d=0.24 en d=0.25 onderskeidelik). Dit was as gevolg van ‘n beduidend hoër TF (p<0.001) en medium effekgrootte (d=0.42) ten spyte van ‘n beduidend (p<0.001) en medium effekgrootte (d=0.73) korter TL in die kaalvoetkondisie. Die beduidend hoër TF wanneer kaalvoet was as gevolg van beduidend korter VT (p=0.022) en klein effekgrootte (d=0.16), ‘n beduidend korter GKT (p<0.001) en medium effekgrootte (d=0.69) en ‘n beduidend korter ST (p<0.001) (medium effekgrootte, d=0.56). Alle verskille in naelloopprestasie en tyd-ruimtelike veranderlikes was as gevolg van die massa van die skoene en nie as gevolg van veranderings in VSP wat deur die skoenkondisies veroorsaak is nie. Verandering van skoene na KV het ‘n beduidende laer voorkoms van hakslag hardlooppatrone meegebring vanaf 57% tot 27% en ‘n beduidende toename in die voorkoms van voorvoet-/middelvoet voetslag (VV/MV) van 43% na 73% (p<0.001). Die skoenkondisie het dus ‘n beduidende hoër voorkoms van agtervoetneersit tot gevolg gehad en die KV kondisie ‘n beduidende hoër voorkoms van voorvoet/midvoetneersit gehad. Skoene het ‘n beduidende akute effek op kort anaërobiese naelloopprestasie, tydruimtelike veranderlikes en voetneersitpatrone by skoolkinders. Kaalvoetnaellope is effens vinniger as skoene oor 10m en 20m, maar dit kan potensieel net van toepassing wees op kinders en adolessente wat gewoond is aan kaalvoet loop. Om KV of in hardloopskoene te nael is bykans dieselfde en kan kinders kies waarmee hulle getoets wil word of hardloop op sintetiese oppervlaktes. Versigtigheid moet aan die dag gelê word by akute oorskakeling van skoene na KV aangesien die risiko van beserings aan die plantaaroppervlaktes kan verhoog.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/101324
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