Association between sensorimotor function and lower limb biomechanics during a single-leg forward hop in athletes after ACL reconstruction.

OBJECTIVES

To compare sensorimotor function and single-leg forward hop biomechanics between return-to-sport (RTS)-cleared athletes after anterior cruciate ligament reconstruction (ACLR) and healthy controls, and to examine sensorimotor-biomechanics associations in ACLR.

DESIGN

Cross-sectional laboratory study; paired/independent t tests and Pearson correlations.

SETTING

Human movement biomechanics laboratory.

PARTICIPANTS

Twenty-four athletes after ACL reconstruction (mean time since surgery: 19.7 ± 6.8 months) who had been cleared for return to sport (RTS), and twenty-four healthy controls.

MAIN OUTCOME MEASURES: Knee strength limb symmetry index (LSI), joint position sense absolute error (30° and 60°), and quadriceps/hamstrings force-sense error assessed using an isokinetic dynamometer, as well as hop-landing kinematics and kinetics assessed using a three-dimensional motion-capture system and force plate.

RESULTS

Compared with controls, ACLR athletes showed greater quadriceps force-sense error (P = 0.011). The involved limb demonstrated lower peak knee flexion, knee flexion moment, and knee flexion power, and greater knee internal rotation angle than the uninvolved limb and controls (P < 0.0167). In the ACLR group, hamstring force-sense error was correlated with greater knee valgus angle (r = 0.670) and lower knee flexion moment (r = -0.445), quadriceps LSI was correlated with greater knee flexion moment (r = 0.559) and lower knee internal rotation power (r = -0.532), and hamstrings LSI was correlated with lower knee valgus angle (r = -0.479).

CONCLUSIONS

Residual sensorimotor deficits persist after RTS clearance and are associated with landing biomechanics, supporting inclusion of sensorimotor testing in RTS evaluation.