A few classic exercise methods: half squat against the wall This method is suitable for all patients who have no restrictions on the weight of the lower limb, if there is cartilage damage to the affected limb, and in the exercise will produce pain, you can avoid the injury zone by fine-tuning the angle up and down, and try to make the exercise does not occur within the pain arc. If the strength reaches a certain level, you can increase the difficulty and the fun of the exercise by changing the way you squat in order to strengthen the effect and practicality of the exercise. Back against the wall, feet and knees shoulder width, toes forward, squat to the tip of the knee and toe line vertical ground (the tip of the knee can not exceed the toe, otherwise it will cause pressure on the patellar cartilage, meniscus), the center of gravity on the affected foot, their own squat depth (pain-free angle, about 45 ° bent knee), each time to maintain a half squat 20 seconds, and then rest 20 seconds for a time, 10-20 consecutive groups (gradual ), 3 groups of days. If you want to increase the difficulty, you can place a soft ball between your back and the wall and perform the same standard exercises. Resistance knee extension This exercise can also be performed on the healthy side, but care should be taken to increase the range and load to differentiate. It is generally indicated for patients with early injury to the non-extending devices of the lower extremity (quadriceps, patella, patellar tendon). If the active extension of the affected limb is limited, emphasis should be placed on strengthening the resistance knee extension exercises in the range of hyperextension to 30° of flexion, strengthening the medial femoral muscle, with no change in the standard of movement. The fact is that the last 30 degrees of joint control is the most significant in a person’s daily work physical exercise. The strength of the medial femoral muscles in this area accounts for more than half of the strength of the entire muscle group, so in most cases the focus should be on exercises in this range of motion. Sit on the edge of the bed (chair or apparatus), tie one end of the elastic band to the foot of the bed and the other end to the ankle of the affected side, perform resistance knee extension exercises in the range of full extension up to 70 degrees, when the knee is extended to the very end, stay for 5 seconds, then rest for one time, 30-50 consecutive sets (progressively), 3 sets of days, the weight of the elastic band chosen to reach full fatigue within 10-15 repetitions and not produce If fatigue and pain conflict, prioritize pain control and extend the pause in the movement to enhance the training effect. The purpose of this exercise is to strengthen the posterior thigh group (N cord muscle). As an antagonist of the anterior group of quadriceps, the posterior group of muscles plays an important role in maintaining the balance of the entire joint and the controllability of joint movements, so it is important to pay attention to it. Patients with posterior cruciate ligament rupture and reconstruction of the knee joint should not do this exercise for 3 months after surgery. The exercise is basically suitable for other patients and does not cause increased pressure on the patellofemoral joint surface, even in patients with more severe degenerative osteoarthrosis. The weight, movement specifications and number of straps used are the same as for the “resistance knee extension” exercise above. This method is suitable for those who do not have any contraindications to weight bearing on the lower limb. Stand with the affected side of one limb fully extended, thigh muscles fully contracted, knee joint “back to the top”, chest up, abdomen, hips and head up, maintain balance, when it reaches a stable standing 1-2 minutes without falling, you can try to take off the abduction. Generally stand for 5 minutes / time, rest interval 10 seconds, 2-3 times / group, 1-2 groups / day. When standing for more than 5 minutes and still able to ensure a smooth body, you can transfer to the balance board to continue this exercise, the standard remains the same. You can also practice 0-45° half squats when your strength increases. Straight leg raise This method can be used for almost any lower extremity injury except for knee extension device injuries. In the sitting or lying position, with the thigh muscles fully contracted, after locking the knee joint, raise the straight leg until the heel is 15 cm above the bed and hold it until exhaustion, with an interval of 10 seconds, 10 times/group, 3-5 groups/day. Side leg raises are also possible. The key to this exercise is to fully straighten the knee joint, the effect of a slight bending exercise is greatly reduced. Modified quadriceps isometric contraction (pinch pillow) This exercise method of extension is still applicable to patients with knee extension device injuries, and it is sufficient to stick to pain-free levels of strength during the exercise, while other patients can practice to the best of their ability. This method of exercise has another significance: contracting the muscle triggers movement of the patellofemoral joint. The movement of the patellofemoral joint maintains the flexibility of the patella after the injury and has a greater effect on preventing stubborn adhesions in the joint. It also ensures the normal elasticity of the muscles and has a greater role in the flexibility of the entire knee joint, which is recommended to be practiced diligently by patients with various injuries. In a seated position, with a straight back and both knees flexed at 90°, place a pillow between the knees and hold the pillow by tensing and relaxing the thigh muscles. Do as many as possible without increasing pain. (More than 500 times/day) Place your hands on your thighs, especially slightly medial to the lower thighs, and experience the contraction of the medial femoral muscles, making sure that each contraction is clearly felt.