Jumping Asymmetries Are Associated With Speed, Change of Direction Speed, and Jump Performance in Elite Academy Soccer Players

Abstract

Jumping asymmetries are associated with speed, change of direction speed, and jump performance in elite academy soccer players. J Strength Cond Res 35(7): 1841-1847, 2021-The aim of this study was to establish interlimb asymmetries across different age groups in elite academy male soccer players and to examine any relationships between asymmetry and measures of physical performance. Fifty-one players from an English Premier League soccer academy were split into under-23 (n = 21), under-18 (n = 14), and under-16 (n = 16) groups and performed bilateral and unilateral countermovement jumps, 5-, 10-, and 20-m sprints, and a 505 change of direction speed tests. All tests showed low variability (coefficient of variation # 2.5%) and good to excellent reliability (intraclass correlation coefficient = 0.80-0.99). A 1-way analysis of variance showed that the under-23 group was significantly faster than the under-16 group during the 20-m sprint (2.90 vs. 2.98 s; p = 0.02; effect size = 0.94). No other significant differences were present between groups. Interlimb asymmetry was quantified from the single-leg countermovement jump, and no significant differences in the magnitude of asymmetry were present between groups. However, multiple significant correlations were present in each age group between asymmetry and physical performance tests, all of which were indicative of reduced athletic performance. Results from this study show that although interlimb asymmetry scores are comparable across age groups in elite academy soccer players, differences as low as 5% are associated with reduced physical performance during jumping, sprinting, and change of direction speed tasks. This study suggests the importance of monitoring jump height asymmetries in elite academy soccer players.

Jumping-based Asymmetries are Negatively Associated with Jump, Change of Direction, and Repeated Sprint Performance, but not Linear Speed, in Adolescent Handball Athletes

“…Although the correlations between jumping asymmetries and physical performance (Table 3) do not show an overall negative influence on the performance of the different tested capabilities, probably because of the taskdependent nature of asymmetries, some negative correlations should stand out. In this sense, negative correlations between jump height asymmetries and jump performance in the SLCMJ ND (r = -0.47) were found in the present study, and similar results have been recently shown at different ages (under-16, r = -0.51, -0.54; under 23, r = -0.52, -0.77 and under-18, r = -0.58, -0.40) in elite academy soccer players (Bishop et al, 2019). Related to jump distance asymmetries, no meaningful correlations were found between SLBJ and jump performance in our study, which is in agreement with previous research using this test in youth female soccer players (Bishop el al., 2018c) and youth tennis players (Madruga-Parera et al, 2019a).…”

“…Furthermore, strength asymmetries have not been related to sprint performance as well (Lockie et al, 2017). These results contrast with others studies in female and male soccer players, where correlations between SLCMJ height asymmetry and reduced sprinting performance were found (Bishop et al, 2018c(Bishop et al, , 2019. The disparity of these data could be explained by the importance of correctly selecting tests to determine asymmetries based on age, gender, sport and positional differences where applicable.…”

“…Although useful, reporting their prevalence alone does little to further our understanding of whether their reduction is needed. For this, investigations into the effects of asymmetries on physical performance represent a useful starting point in understanding their importance (Bishop et al, 2018d;Bishop et al, 2019;Madruga-Parera et al, 2019a;Maloney, 2018). When looking at the effects on performance, jump testing has been a common line of investigation, most likely because of its time-efficient nature and relatively easy test procedures (Bishop et al, 2017).…”

Strength, Jumping, and Change of Direction Speed Asymmetries Are Not Associated With Athletic Performance in Elite Academy Soccer Players

“…For example, Bishop et al (2018b) showed that jump height asymmetries from the unilateral countermovement jump (CMJ) were associated with slower 5-m (r = 0.49), 10-m (r = 0.52), and 20-m (r = 0.59) sprint times in elite youth female soccer players. Additionally, in elite academy soccer players of multiple age groups, ranging from younger than 16 to younger than 23 years old, Bishop et al (2019b) showed that jump height asymmetry (again from the unilateral CMJ) was associated with slower times in 5-(r = 0.60-0.86), 10-(r = 0.54-0.87), 20-m (r = 0.56-0.79) sprints, and it also affected performance in the 5-0-5 test in either limb (r = 0.61-0.85). In contrast, Lockie et al (2014) reported jump height and distance asymmetries during the unilateral CMJ (10.4%), lateral jump (5.1%), and broad jump (3.3%) tests in male collegiate athletes.…”

Interlimb asymmetry thresholds that negatively affect change of direction performance in collegiate American football players

“…Interest in the effects of interlimb asymmetry, with respect to successful sports performance, has increased in recent years. Literature highlights associations between lower extremity neuromuscular function (e.g., unilateral power production capability) and performance in sport-related tasks such as jumping, 1 sprinting, 2 and change of direction (CoD), 1,3,4 but literature attests that asymmetries do not appear to bring clear influence on athletic performance measures. 5 Research focused on the magnitude of asymmetry that may meaningfully affect sports performance is lacking, and we have suggested that identifying meaningful asymmetry thresholds are necessary to offer evidence-based targets for practitioners looking to assess and reduce asymmetries that may negatively affect sport performance.…”