When a patient suffers an ACL rupture of the knee and is treated surgically, postoperative rehabilitation focuses on restoring flexion and extension of the knee. Specifically, the patient can be instructed to lie in the prone position, then the popliteal fossa of the knee is immobilized, and the patient is instructed to lift the heel as much as possible towards the buttocks in order to maximize the movement of the knee joint. The patient can also be instructed to sit in the sitting position, sit on the edge of the bed to immobilize the knee, and then move the lower leg down as far as possible. The patient can also be instructed to lie in the supine position, then lift the affected limb, flex the hip, flex the knee and do the bicycle movement, the purpose of which is to move the knee flexion and extension activities. In all rehabilitation processes, the patient’s movements should be slow and not overly forceful, so as not to aggravate the injury.