Vertical and Horizontal Asymmetries are Related to Slower Sprinting and Jump Performance in Elite Youth Female Soccer Players.
Inter limb asymmetries have been shown to be greater during vertical jumping compared to horizontal jumping. Notable inter limb differences have also been established at an early age in male youth soccer players. Furthermore, given the multi planar nature of soccer, establishing between limb differences from multiple jump tests is warranted. At present, a paucity of data exists regarding asymmetries in youth female soccer players and their effects on physical performance. The aims of this study were to quantify inter limb asymmetries from unilateral jump tests and examine their effects on speed and jump performance. Nineteen elite youth female soccer players performed a single leg countermovement jump (SLCMJ) single, triple, and crossover hops for distance and a 20 m sprint test. Test reliability was good to excellent (ICC 0.81 0.99) and variability acceptable (CV 1.74 5.42% A one way ANOVA highlighted larger asymmetries from the SLCMJ compared to all other jump tests (p 0.05) Pearson's correlations portrayed significant relationships between vertical asymmetries from the SLCMJ and slower sprint times (r 0.49 0.59) Significant negative relationships were also found between horizontal asymmetries during the triple hop test and horizontal jump performance (r 0.47 to 0.58) and vertical asymmetries during the SLCMJ and vertical jump performance (r 0.47 to 0.53) The results from this study highlight that the SLCMJ appears to be the most appropriate jump test for identifying between limb differences with values ~12% showing negative associations with sprint times. Furthermore, larger asymmetries are associated with reduced jump performance and would appear to be direction specific. Practitioners can use this information as normative data to be mindful of when quantifying inter limb asymmetries and assessing their potential impact on physical performance in youth female soccer players.
Journal of strength and conditioning research