Compared to controls, subjects who had undergone anterior cruciate ligament reconstruction (ACLR) had significant inter-limb differences in medial hamstring electromyographic (EMG) activity during the single-leg hop test.

Also, the volume of the biceps femoris short head and semitendinosus was smaller in the operated leg. However, it was the semimembranosus volume which showed an association with subjective knee function scores.

These findings indicate that inter-limb differences in hamstring function and morphology can affect the ACLR outcomes even multiple years after surgery.