Lower limb muscle fatigue on grass and artificial turf playing surfaces among elite soccer players

[摘要] INTRODUCTION: Fatigue and hard playing surfaces have been indicated as riskfactors for injury in soccer players. Recent literature, however, has foundcontradictory results on the prevalence of injuries on different playing surfaces, aswell as regarding the interaction between fatigue and the type of playing surface.This raises the question as to the true mechanisms underlying the cause of injury ondifferent playing surfaces.AIM: The aim was therefore to compare lower limb muscle fatigue on grass andartificial surfaces in elite soccer players.METHODS: Twenty two elite soccer players (mean age 24.8 years) were included ina cross-over study design. The players were randomly allocated to two conditions.It involved exposure to the same soccer-specific fatigue protocol on a grass andartificial surface respectively. A force plate was used for pre-test and post-fatiguemeasurements on force generation, force rates and jump height. The Pearsoncorrelation coefficient was used to determine associations between baselinevariables and interpreted by means of effect sizes and p-values. The Wilcoxonsigned-ranks test was used to determine statistical significant changes from pre-testto post-test for each condition while the Chi-square test was used to compare thefindings between the two conditions.RESULTS: Statistical significant correlations were found at baseline betweenpropulsion and concentric forces (r=0.66, p<0.001); propulsion force and body mass(r=0.78, p<0.001); propulsion force and BMI (r=0.645, p<0.01); landing force andbody mass (r=0.82, p<0.001); landing and eccentric forces (r=-0.75, p<0.001); jumpheight and concentric force (r=0.84, p<0.001); and body mass and concentric force(r=0.76, p<0.05). Propulsion and concentric forces increased statistical significanceafter fatigue on the grass surface (p=0.026 and 0.005 respectively). On the artificialsurface there was a statistical significant increase in propulsion force and propulsionforce rate post-fatigue (p=0.0001 and 0.0153 respectively). Comparison of the changes from baseline to fatigue between the two conditions yielded no significantdifferences (p>0.05).CONCLUSION: Limited significant differences were found comparing forces afterfatigue on artificial and grass surfaces. The inconsistency in the behaviour of forcesin response to fatigue indicate the possible variability in adaptation strategies to copewith a speculated fatigue state. Surface-specific training could therefore berecommended in order for muscle and sport/surface-specific adaptation to takeplace, thereby decreasing the risk for injury

[发布机构] University of the Free State