Search

This study assessed whether trunk flexor and extensor strength were predictors of time to stability (TTS) and center of pressure (CoP) during hop and hold tasks in children. Seventeen boys (age, 10.1 ± 1.6 years; height, 1.45 ± 0.11 m; mass, 26.7 ± 7.83 kg) undertook isokinetic strength assessments of concentric and eccentric trunk flexors/extensors at 60°/s, and anterior/medial hop tasks. Hierarchical multiple regressions determined whether concentric and eccentric trunk flexor/extensor peak torques predict TTS using a composite score (Comp[subscript X] Comp[subscript Y] Comp[subscript Z]) and CoP[subscript X] and CoP[subscript Y]. Concentric trunk flexors were the strongest predictor for TTS Comp[subscript XY], with concentric flexion and eccentric extension predicting TTS Comp[subscript Y]. All muscle actions were also strong predictors for CoP[subscript Y] during hop tasks. These findings have implications for the assessment of trunk musculature strength and measures of postural control within a young healthy population. The development of trunk musculature strength may aid improvements in dynamic balance tasks in children, with implications for fall and injury risk. To improve trunk musculature strength and the potential to maintain postural control, a combination of concentric and eccentric exercises with other training modalities appears relevant due to the increased relevance to the demands of balance maintenance.

The purpose of this study was to assess whether dynamic torque ratios (DCR) from isokinetic strength assessments of eccentric knee flexors (eccKF) and concentric knee extensors (conKE) display differences when stratified into specific angle-specific DCR (DCRAST) groups. Fifty-two professional female soccer players (age 21.30 ± 4.44 years; height 166.56 ± 5.17 cm; mass 61.55 ± 5.73 kg) from the English Women's Super League completed strength assessments of both lower limbs on an isokinetic dynamometer at 60°∙s−1. Angle-specific torque (AST) were used to calculate DCRAST to create sub-groups using clustering algorithms. The results identified for the dominant side that the Medium DCRAST group elicited significantly higher conKE AST when compared to Low and High DCRAST groups at increased knee extension (P ≤ 0.05). For the non-dominant side, the High DCRAST group had significantly higher and lower eccKF and conKE AST compared to the Low DCRAST group at increased knee extension (P ≤ 0.05). This study highlights that the inclusion of AST data may subsequently help practitioners to prescribe exercise that promotes strength increases at targeted joint angles. In turn, these approaches can be used to help reduce injury risk, identify rehabilitation responses and help inform return to play. [ABSTRACT FROM AUTHOR]