According to the actual situation of the injury, refer to the N cord muscle rehabilitation program, choose the appropriate stretching and muscle strength training methods. Stretching training 1, sitting knee extension training: sitting on the ground or training mat, legs as straight as possible forward, body sitting straight, you can feel a partial pulling sensation at the back of the thigh. Each time for 3-5 minutes, but do not hold the position for a long time. 2, standing position N rope muscle extension training: the affected leg heel placed on a bench about 40cm above the ground. Keep the affected foot straight, body leaning forward, when you feel a pulling sensation in the back of the thigh can be appropriate to bend the hip joint. Keep the neck and shoulders do not rotate when training, the waist position leaned forward, pulling induction from the back of the thigh rather than the calf, we are pulling the back of the thigh N rope muscle. Continuous pulling 15-30 seconds, 3 times a day. 3, against the wall N rope muscle stretching training: lying flat on the ground, buttocks near the edge of the wall, the affected leg straight lift on the wall, the other leg near the corner of the wall straight forward, the two legs are roughly 90 degrees. Make the affected leg against the wall and lean hard. At this point, you will feel a pulling sensation at the back of the thigh. Continue pulling for 15-30 seconds, 3 times a day. (As shown in the figure) 4, standing gastrocnemius extension training: training facing a wall, hands forward to push the wall and the level of the eyes flush. The affected leg is behind, normal in front; the affected leg is properly tucked in, and the heel is on the ground as a support leg. As your body slowly approaches the wall, the gastrocnemius muscle at the back of the calf feels tense. The pulling sensation can be adjusted by straightening and flexing the knee joint of the affected leg. Each pulling movement lasts about 15-30 seconds. 5 sets of 3 reps each time. (As shown) 5, static N rope muscle stretching training: internal rotation position: the affected leg straight, the other leg slightly bent to sit. Make the straightened leg rotate inward, then bend the hip joint so that the body leans forward and feel the pull on the muscles behind the thigh (as in Figure 1). Continue the pulling action for about 30 seconds. 4-5 times a day. External rotation position: straighten the affected leg and sit with the other leg slightly bent. Rotate the straightened leg outward, then bend the hip joint so that the body leans forward and feel the pull on the posterior thigh muscles (Figure 2). Continue the pulling action for about 30 seconds. 4-5 times a day. 6, dynamic stretching training: one hand side support, use the affected leg off the ground, swing back and forth, lift off the height gradually increase (Figure 4 & 5). About 10-15 round trips. Do this every morning after waking up to regulate the length of the muscle fibers, stimulate the muscle shuttle receptors, and get a full day of rest and relaxation, but please do not push too hard. Dynamic stretching is not easy to do in the early stages of an injury, as it can easily cause pain. Dynamic stretching takes advantage of the properties of the myofibrils in the muscle fibers. We know that the muscle tissue contains the myosin, which is a receptor that senses the pulling stimulus of the muscle. By gradually elevating the affected leg, the muscle shuttle is stimulated to lengthen the muscle fibers in a moderate and safe manner. However, if the muscle tissue is stretched excessively by an external force, the detrusor reflex is stimulated to cause shortening of the muscle fibers. This change is called impact pulling and can cause muscle fiber damage. Dynamic stretching exercises play a very important role in restoring normal physical performance and movement. This is especially true when speed exercises are required. Muscle tissue needs to be able to obtain full mobility contraction in speed exercises, not just static stretching. 7, proprioceptive neuromuscular facilitation training (PNF) PNF stretching training techniques involve the detrusor reflex. These exercises increase muscle fatigue and therefore should not be performed early in the injury. Training methods are as follows: first warm-up exercises, you can moderate sprints or straight leg down resistance pushing 20 times in the flat position. Training method: lying down, with the help of an assistant straight leg lift the affected leg to pull the posterior thigh N rope muscle, slow and gentle movements, as far as possible until the pull can not. Feel the pulling sensation at the back of the thigh, but keep pain-free to tolerate under. (1) resistance action: the affected limb is straightened, the assistant pushes upward with 50% resistance, while the affected limb is pushed downward. The resistance must be high enough that the leg cannot move significantly. Continue for about 10 seconds. (2) Relaxation maneuvers: Active straight leg raise with active contraction of the quadriceps muscle in front of the main thigh. Repeat these movements until they can be done easily without any difficulty. Plyometric training 1, standing knee flexion training: without causing pain, the training can be started early in the injury. Depending on the degree of injury, mild injuries can start training from the first day after the injury, more serious injuries can be delayed. Training method: Stand facing the wall and slowly flex the knee joint, keeping both knees side by side (as shown in the figure). Each set of 10 times, each time 3 sets, and then a short rest. (As shown) 2, prone position knee flexion training: training, prone lying flat, legs straight. Then bend the knee joint, so that the heel as close to the hip. Continue for 5 seconds, then relax back to the starting position. Perform 3 sets of 10 reps each. When you can easily complete without any difficulty, you can tie a sandbag to the ankle to increase the load exercise. 3, straight leg raise training: (1) prone position, legs straight, using the hip muscles to lift the affected leg upward, lift the height to feel no discomfort, generally at least 20cm or so. Keep the elevated state for about 5 seconds each time; then relax to the starting position and rest briefly. 3 sets of 10 reps each time. (2) In the supine position, with the legs straight, raise the affected leg straight, and the healthy leg can be assisted by bending the knee. Hold the elevated state for 5 seconds at a time, then relax to the starting position. 3 sets of 10 reps each time.