Taijiquan is a traditional fitness sport in China. With the popularity of mass sports, more and more people like to play taijiquan, but there are also more and more people who play taijiquan induced or aggravated knee disease, playing taijiquan in the end to strengthen the body is not helpful? First of all, we need to analyze the characteristics of Taijiquan: Taijiquan is a full-body exercise, the basic purpose of which is to exercise the muscles and joints of the whole body, which is characterized by slow movements, mostly semi-squatting movements. For many people, it can be very difficult to complete a standard set of taijiquan movements because of the excessive half squatting or static squatting movements. The human knee joint consists of the distal femur (thigh bone), the proximal tibia (calf bone) and the patella (kneecap). The distal femur and proximal tibia constitute the knee joint in the narrow sense (femoral-tibial joint), and it is the femoral-tibial joint that we rely on when walking on a flat road, and when this joint area becomes diseased, pain will occur when walking on a flat road. The patella and the distal femur constitute the patellofemoral joint, and the patellofemoral joint both bears and transmits stress during squatting. Once this joint is damaged, it will cause the inability to go up and down stairs, go up and down slopes, squat or stand up after squatting. The inner and outer sides of the kneecap are held by soft tissues (called the medial and lateral patellar support bands respectively) to maintain its stability, and connected to the proximal side of the kneecap are the quadriceps muscles including the medial femoral muscle, the middle rectus femoris and the middle femoral muscle, and the lateral femoral muscle. When we squat, stand, or extend the leg, the quadriceps acts on the tibia through the patella to produce the stress of extending the leg or standing up. The knee joint generally begins to “age” at about 45 years of age, initially mainly due to softening and wear of the articular cartilage. The patella is prone to contracture due to the fibrous component of the lateral femoral muscle. In addition, the contracture of the lateral patellar support band will cause the patella to shift laterally and be semi-dislocated, so the early patellofemoral joint cartilage wear is mainly in its lateral part. For the knee joint, the half-squat movement will significantly increase the stress on the structures within the joint. First of all, for the femoral-tibial joint, the stress transmission changes from linear to torsional when the joint is fully standing, and the stress is significantly increased, while the contact area of the femoral-tibial bone decreases during the half squat, and the stress (compression) on the local cartilage increases, which can cause premature cartilage degeneration. For the patellofemoral joint, half squatting than daily walking stress to increase 3-4 times, half squatting force will even increase to more than 10 times, for the joint has potential pathological changes, each half squatting activity is obviously a blow, will accelerate the breakdown of cartilage. Therefore, for the elderly, you should reduce the number of stairs, up and down slopes, half squats and other activities, not to mention these activities as a form of exercise, otherwise it will be counterproductive. For the elderly, in order to exercise the knee joint and prevent premature aging, you can do the following health exercises: a. non-weight-bearing activities exercise: such as swimming, cycling, etc.; b. non-squatting activities: such as scattering, jogging, time to not cause knee pain; c. straight leg raise exercise in the case of external rotation of the lower leg: can increase the muscle strength of the medial femoral muscle, relieve the patella to the lateral deviation, slow down the The patella is pushed inward horizontally from the lateral patella, which can relieve the contracture of the lateral patellofemoral support band and reduce the pressure on the lateral patellofemoral joint.