Agreement between Inter-Limb Asymmetries in Single and Triple Unilateral Hops, and Associations with Bilateral Jumping and Sprint Performance in U17 and U19 Soccer Players

Abstract

The purpose of this study was to investigate the agreement regarding the direction of interlimb asymmetry (ILA) between different horizontal jumping tests, to examine the differences in ILA between different age categories and to assess the relationship between ILA and sprint and jump performance. The sample included 38 elite youth male soccer players from two distinct age categories (U17 and U19). The testing procedure consisted of a 10 m sprint test, unilateral and bilateral broad jumps, and unilateral and bilateral triple hops. The results showed moderate correlation and fair agreement in the direction of ILA between single broad jumps and single-leg triple hops (κ = 0.42; p = 0.014). The magnitude of ILAs tended to be larger in the unilateral triple hop (5.41 ± 5.25%) compared to the unilateral single hop (3.54 ± 2.67%). Furthermore, the older group had smaller ILA magnitudes in both jumping tests, with significant differences between age groups being observed only in single hops (p = 0.46; d = 0.78). Additionally, significant associations were found only between the ILA unilateral triple hop with bilateral single jump (r = −0.39) and sprint performance (r = 0.40), while ILA in the broad jump showed no significant associations with performance metrics. Based these results, the unilateral triple hop could be recommended as the preferred horizontal jump variation for screening soccer players. Furthermore, in line with the literature, mean ILA in horizontal jumps were far below the commonly used threshold of >10–15% (mean ILA 3.5–6.5%), which suggests that the ILA threshold for horizontal jumps should be reconsidered.