The role of calf muscle strength in shaping proximal joint mechanics during jump-landing in female athletes with and without dynamic knee valgus.

backgroundDynamic knee valgus (DKV) leads to changes in the mechanics of the lower limbs and can disrupt neuromuscular control. Understanding how calf muscle strength affects landing patterns is crucial, as it can offer important insights into the compensatory strategies used by individuals both with and without DKV. Therefore, this study examines the relationship between the isokinetic strength of the calf muscles and lower limb kinematics during jump-landing in female athletes with and without DKV.

methodsThis controlled laboratory study included female athletes with DKV (N = 15) and without DKV (N = 13). The jump-landing kinematics and strength of the plantar flexor muscles were measured with 10-camera motion analysis (Santa Rosa, USA) and the Biodex isokinetic (Biodex, USA), respectively. An independent t-test was used for group comparisons, and Pearson and Spearman correlation coefficients were applied to examine relationships between variables.

resultsIn the group of non-DKV athletes, we found significant correlations between knee adduction and abduction angles and various strength measures. Specifically, there were significant relationships with peak eccentric dorsiflexor torque at 120°/s (p = 0.015), average power of concentric plantarflexors at both 30°/s (p = 0.002) and 120°/s (p = 0.004), as well as eccentric plantarflexor strength at 30°/s (p = 0.001) and 120°/s (p = 0.015). Furthermore, hip internal and external rotation angles showed a positive correlation with the average power of plantarflexors during eccentric contractions at 30°/s (p = 0.046) and concentric contractions at 120°/s (p = 0.043). In contrast, the DKV group revealed only one significant association, which was between hip flexion and extension angles and eccentric plantarflexor power at 120°/s (p = 0.039).

conclusionsThis study highlights how important calf muscle strength, especially the plantarflexors, is for the mechanics of proximal lower-limb joints during single-leg landings in female athletes. For those without DKV, stronger and more powerful plantarflexors were linked to better alignment of the knee and hip joints, suggesting effective distal-to-proximal coordination within the lower limb. However, in the group with DKV, this connection was significantly weaker, suggesting that movement specialist should pay attention to alignment when designing the corrective exercise program.