Changes in Isokinetic Muscle Strength of the Lower Extremity in Recreational Athletes With Anterior Cruciate Ligament Reconstruction

Objective: To investigate changes in muscle strength in the lower extremity after ACL reconstruction. Design: Prospective case series. Dependent Variables: Isokinetic muscle strength measured in 6 movements (hip extension/flexion, hip adduction/abduction, knee extension/flexion) and circumference of the thigh/calf. Setting: Clinic and home. Patients: 44 (24 men, 20 women) between the ages of 16 and 47 years with an ACL rupture. All underwent reconstruction via a semitendinosus autograft. Main Outcome Measures: The peak torque for each joint movement was recorded. Repeated-measures ANOVA and power analysis were conducted to detect significant interaction effects. Results: The decline of muscle strength after ACL reconstruction remained not only in the knee extensors and flexors but also in the hip adductors. Conclusion: Rehabilitation programs that address the behavioral patterns and physiological characteristics of an ACL injury will benefit the athlete’s whole body and lead to a full recovery.