Inter-limb asymmetries and kicking limb preference in English premier league soccer players

Abstract

The aims of this study were: (1) to quantify interlimb asymmetries in EPL soccer players in the context of kicking limb preference and (2) to establish the relationship between interlimb asymmetries and measures of physical performance. Twenty-two players (age: 21.8 ± 4.4 years) from an EPL club performed a running gait assessment (20 km/h) and unilateral countermovement jumps, a CoD assessment (modified 505 test), and an isokinetic knee extension/flexion protocol using each leg. Asymmetries were quantified using the percentage difference method and Pearson's correlations were used to quantify the association between variables. Players displayed the greatest level of asymmetry in isokinetic strength measures (5.9–12.7%) and lower levels of asymmetry in gait (1.6–7.7%), jump (0.9–7.0%) and CoD (1.9–3.5%) assessments. The influence of the preferred kicking limb was most evident in the isokinetic assessment with the players showing dominance in the preferred limb for knee flexor strength and in the non-preferred limb for knee extensor strength. These manifested in the asymmetry values calculated for the hamstring:quadricep (H:Q) ratios at 60°/s (8.80 ± 7.82%) and 240°/s (11.22 ± 7.04%) and in the functional H:Q ratio (12.67 ± 8.25%). The asymmetry values for peak extensor moment at 240°/s showed a significant correlation (ρ = −0.55, p = 0.034) with 10 m time in the CoD assessment. These findings provide benchmark asymmetry data for soccer practitioners and reveal that kicking limb preferences may bring about interlimb differences in the H:Q ratio which raises important considerations in the design of testing batteries and injury reduction interventions.

Recommendations for the Isokinetic Test of Female’s Soccer Players Knee: A Systematic Review

“…It was found that male professional soccer players of the English premiere league displayed a greatest level of inter-limb asymmetry in isokinetic strength measures (5.9-12.7%. This measure is consistent with gait asymmetry (1.6-7.7% varia-bility in running stride length between the two legs) and jump asymmetry (0.9-7.0%) [33]. Considering the psychology, isokinetic testing is strictly depended on sincerity of effort [1].…”

Changes in hamstring contractile properties during the competitive season in young football players

“…Lateral asymmetry within the same muscle group ( e.g ., right BF vs . left BF) has the potential to negatively affect balance in both legs and may be associated with risk factors for muscle injury ( Gil et al, 2015 ; Nicholson et al, 2022 ). However, in football, complex movement tasks have been performed that may mask muscle asymmetry as they involve interaction with the movement of other muscles ( Macgregor, 2016 ).…”

“…In the pursuit of effective injury prevention, a thorough assessment of athletes’ health and neuromuscular function is paramount. Research suggests for example, that asymmetry in muscle function, particularly within the stretch-shorten cycle, could be a potential risk factor for injuries ( Gil et al, 2015 ; Nicholson et al, 2022 ). While various methods, including isokinetic assessments and electromyography (EMG), have been investigated for predicting injury risks, they often pose practical challenges in terms of time and equipment requirements ( Torres et al, 2020 ; Konieczny, Pakosz & Witkowski, 2020 ).…”

Intra- and inter-limb strength imbalance and asymmetry in soccer: A comparison of elite senior and junior players

“…An isokinetic dynamometer also enables reliable assessment of the muscular strength imbalance of the lower limbs, both bilateral (inter-limb asymmetry) and unilateral (intra-limb imbalance or flexor-extensor muscles ratio or intra-limb ratio) [4,[11][12][13][14][15]. Muscle strength asymmetries may negatively affect specific performance [3,[16][17][18][19], and soccer-related abilities [20,21], thus significantly limiting the players' sporting performance [14,18,21]. In addition, muscle strength imbalance and asymmetry is a particularly important predictor of many different injuries in soccer players [2,11,12,14,15,[22][23][24][25].…”