The effects of knee ligament load using simulated hip abductor and hamstring muscle strengthening during cutting...

This study aimed to analyze knee ligament of load and joint moment to simulate the strengthening of the hip abductor and hamstring muscles using musculoskeletal modeling, thereby contributing to decrease of knee ligament load.

Forty participants (age: 21.85 ± 1.90 years; height: 1.76 ± 0.06 m; body mass: 68.5 ± 7.06 kg) were instructed to run at 4.5 ± 0.2 m/s from a 5 m distance posterior to the force plate, land their feet on the force plate, and perform the cutting maneuver on the left. In the musculoskeletal modeling, the hip abductor and hamstring muscles were targeted to construct a model with a 30% increase in the contraction force of the hip abductor, hamstring, and both 2 muscles. The variables were the ligament force and knee joint moment. One-way repeated measure ANOVA and Bonferroni test were used to compare the abductor/hamstring, abductor, hamstring and control models.

There were significant differences in anterior bundle of the anterior cruciate ligament (ACL) (P = .001), inferior bundle of the superficial layer of the medial collateral ligament (MCL) (P = .016), and posterior bundle of the superficial layer of the MCL (P = .022) force. The post hoc showed that the hamstring model had lower anterior bundle of the ACL and inferior bundle of the superficial layer of the MCL than the abductor/hamstring and abductor models (P < .05) and lower posterior bundle of the superficial layer of the MCL than the abductor and control models (P < .05). There was a significant difference in the adduction (P = .028) and internal rotation moments (P = .014). The post hoc showed that both moments were lower in the hamstring model than in the other models (P < .05).

The hamstring strengthening may contribute significantly to preventing ACL or MCL injury by reducing knee ligament load.