Modeling the neuromotor capacities of professional soccer player with a lower-limb injury during a Countermovement Jump

This study investigated the effects of lower-limb injuries on neuromotor capacities in a cohort of professional soccer players. Three injuries were assessed: chondropathy (CH, n = 10), thigh muscle-strain (MI, n = 15) and ACL-ruptures (ACLR, n = 15). Muscle activation, kinematics and kinetic parameters were recorded during a single-leg and double-leg Countermovement-jump. Values were compared to the dominant-leg of a healthy professional soccer players cohort (CT, n = 22). Results showed that ACLR was the most impactful injury particularly for kinetic variables: Reactive-Strength-Index-modified ( p < 0.001, d = 1.1), jump height ( p < 0.001, d = 1.1), rate-of-force development ( p < 0.001, d = 1.0). CH was the second most impactful pathology ( p < 0.001, d : 0.9–1.1) while results in MI were similar to CT ( p > 0.05). Regarding kinematic variables, compensations were observable and dependent upon injury type. ACLR and CH were more impacted by compensation than MI using superior trunk-flexion and lateroflexion, lower knee-flexion in push-off and higher knee-flexion in landing. Concerning muscle activation, CT active more the semitendinous ( p < 0.05, d = 0.6) and vastus-medialis ( p < 0.05, d = 0.5). CH activated the most gastrocnemius-medium ( p < 0.05, d = 0.6) and biceps-femoris for ACLR ( p < 0.01, d = 0.7). Kinetics and muscle activation analysis during a vertical jump-test showed that CH and ACLR injuries were most impacted. It is useful to model the specific injury impact and manage rehabilitation and return-to-play processes.