The patient’s calf bends backward, can be corrected by the following methods: First, strengthen the exercise: strengthen the muscle strength training behind the knee joint, such as the biceps femoris, triceps calf muscle, hamstring muscle, mainly resistance calf flexion exercises, exercise time of not less than 30 minutes a day, adhere to the obvious therapeutic effect of 3-6 months, can reduce the calf bends backward clinical symptoms. Second, surgical treatment: If there is knee instability, when the calf bends backward, surgical treatment should be considered, usually choose arthroscopic posterior cruciate ligament reconstruction surgery, to restore joint stability, to correct the deformity of the calf bends backward. Postoperative muscle exercises are also needed to maintain knee stability. Once a patient develops backward bending of the calf, it is important to pay close attention to it. Prompt treatment can provide complete relief of clinical symptoms and prevent serious degeneration of the joint.