Therefore, discuss your program with someone. Once you have full motion in bending and straightening then you need to work on quadriceps muscle and hamstring muscle flexibility. The calf, illiotibial band, and hip are three other areas that commonly get tighter. If you had a regular stretching program before the injury most of these should be continued. Any sideways stresses on the knee should be avoided.
Many people use activities that allow full motion but are controlled.
Deep water workouts are one example of this. Although the entire lower extremity is affected by the knee injury, the quadriceps muscles on the front of the thigh are the most affected. Also, the hamstring muscles on the back of the thigh are of particular importance because they stabilize the knee. Start early with cycling, progress to interval training. Progress gradually as symptoms improve to lunges, eccentrics, and gentle plyometrics.