Isokinetic strength and functional capacity in soccer players 24 months after anterior cruciate ligament reconstruction
Abstract
Study aim
This cross-sectional study aimed to compare inter-limb differences in isokinetic peak torque (PT), hop performance, and dynamic balance in soccer players 24 months post-ACLR, and secondarily to examine associations between PT and functional test performance.
Methods
Twenty-four soccer players who had undergone ACLR 24 months prior were assessed. Isokinetic PT of the knee extensors and flexors was measured at 60, 180, and 300°/s. Functional performance was evaluated using the single hop for distance, the 30 s side hop (SH), and the Y-balance test (YBT). Paired-samples t-tests assessed inter-limb differences; Pearson correlation analysis SHD examined associations between PT and functional outcomes.
Results
Significant inter-limb differences were found in knee extensor PT at all velocities and in flexor PT at 60°/s. Mean inter-limb differences ranged from 10.25 to 17.08 Nm for knee extensors and were 7.54 Nm for knee flexors at 60°/s (Cohen’s d = 0.45–0.65). No differences were found in hop or YBT scores. A substantial portion of participants did not meet the symmetry threshold for isokinetic strength or SH performance. SH performance was significantly associated with extensor and flexor PT at specific velocities, while extensor PT was also associated with selected YBT directions and the composite score.
Conclusions
In this sample of male soccer players, strength asymmetries may persist 24 months post-ACLR, although group-level differences in hop and YBT performance were not observed. SH and selected YBT outcomes may complement, but not replace, isokinetic evaluation.
© 2026 Konstantinos Chatzilamprinos, Eleni Semaltianou, Dimitrios Lytras, Vasileios Georgoulas, Ioannis Algiounidis, Evaggelos Sykaras, published by University of Physical Education in Warsaw
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