Inter-limb asymmetry in youth elite soccer players: Effect of loading conditions

Abstract

The presence of inter-limb asymmetries can influence strength performance and represent an injury risk factor for team sport athletes. The present study aimed to investigate the effects of changes in resistance loads using different assessment modalities on the magnitude and the direction of inter-limb asymmetry within the same leg. Fifteen young elite soccer players from the same professional academy performed rear-foot-elevated-split-squat-test at different loading conditions (body mass with no overload, 25% of body mass, 50% of body mass 50%), isokinetic knee flexor (concentric 30°·s-1, concentric 60°·s-1, eccentric 90°·s-1) and extensor (concentric 60°·s-1, eccentric 60°·s-1). The outcomes from the agreement analyses suggested moderate level agreement between body mass vs body mass 25% (Kappa = 0.46), with no agreement or fair agreement for the other between-assessment comparison. Our results demonstrated that the magnitude and direction of within-limb strength imbalances were inconsistent when compared within the same assessment under different resistance load conditions.

Relationships of lower extremity and trunk asymmetries in elite soccer players

“…Reducing something may not necessarily result in injury prevention, as current scientific evidence is not in agreement with the baselines. However, the majority of research on elite soccer players suggests that strength asymmetries can impact performance, particularly in short sprints and dynamic tasks, and increase the risk of injury, especially hamstring strains and muscular imbalances (Lehance et al, 2008;Fousekis et al, 2010a;Sannicandro et al, 2011;Bishop et al, 2021;Ascenzi et al, 2022;Stella et al, 2022).…”

Musculoskeletal Asymmetries in Young Soccer Players: 8 Weeks of an Applied Individual Corrective Exercise Intervention Program

“…A previous study from our laboratory, for example, examined the effect of postural asymmetries on some exercise performance parameters, and suggested that kyphotic and scoliotic postural asymmetries deteriorate neuromuscular explosiveness performance and diminish lower limb flexibility in young internationallevel soccer players [7]. Other recent studies suggested that the presence of inter-limb asymmetries may negatively affect dynamic task performance and represent an injury risk factor in male soccer players [47], and that the magnitude and direction of withinlimb strength imbalances were inconsistent when compared within the same assessment under different-resistance load conditions in youth elite soccer players [48]. Using also Y-Balance-Test scores, González-Fernández et al (2022) [49] examined postural stability and inter-limb asymmetry in the anterior, posteromedial and posterolateral directions in youth and mature semi-professional soccer players with different competitive levels and playing positions, revealing that inter-limb asymmetry showed higher values in lower age categories, and center-backs were worse than wingers and forwards.…”