The authors of this study examined psychological readiness to return to sport in 18 athletes after surgical repair of the anterior cruciate ligament. They also measure strength and single-leg landing biomechanics.

Greater movement of the knee in the frontal plane, and lower movement of the hip in the same plane, were associated with a greater readiness to return to sport.

The full paper is available at https://www.clinbiomech.com/article/S0268-0033(18)30715-0/fulltext