CPM is continuous passive activity, and CPM machine is a joint function exerciser with continuous passive activity. Based on the theory of continuous passive movement, it is an apparatus for lower limb joint function recovery training by simulating the natural movement of human body and stimulating the natural resilience of human being to play the role of tissue compensation. Precautions: Preparation: Adjust the length of the CPM machine bar according to the length of the patient’s affected thigh and calf, and tighten the knob. Place the affected limb on the CPM machine, with the foot and foot sleeve of the affected limb set solidly at 90 degrees to the horizontal line. Tie the thigh and calf to the CPM machine. Training angle: Start with a small angle (0 degrees to 30 degrees) and gradually increase the activity (10 degrees per day) until the patient’s maximum tolerance level. During the application of the CPM machine, the increase in angle should be gradual and the speed should be slow to fast, so as to be acceptable to the patient, thus reducing the patient’s discomfort. Timing of discontinuation: generally 2-3 weeks of use.