I. Normal physiological movement of the knee joint The normal physiological movement of the knee joint is the longitudinal flexion and extension movement. In Taijiquan movement to avoid gravity on the knee joint. When transferring the center of gravity, the soles of the feet should be exerted and the knees outwardly supported, and gravity will naturally be transferred to the hips, which is the principle of human mechanics. In taijiquan exercise you have to learn to think taiji first and change the usual habits of exertion. This is a very important step. Second, the correct practice of taijiquan to prevent knee injuries 1, in the practice of the entire process of taijiquan, the knee is not to be stressed, the force should be placed in the crotch. The knee joint is only a point of force, not a point of force. Avoid twisting the knee to shift the center of gravity. If the knee has old problems or injuries, be more careful. 2, the direction of movement of the knee joint is directly to the direction of the toe, but not over the toe. Its main method is to collect the hips, otherwise the front point of the knee joint will easily cause pain. 3, the exercise process, such as the knee sore feeling, do not be too heavy psychological burden, do not be afraid, after rest, the discomfort will disappear. If it is a strain or sprain of the knee joint, it is a stinging sensation. 4, if there are old problems, to strengthen the maintenance of the knee joint, before practicing boxing to fully move the knee joint, do enough warm-up exercises. Note after practicing boxing Do not wash with cold water or wind blowing, to hot compress and massage. The correct way to practice, not only will not cause injury, but also heal old knee problems. 5, do not be afraid of knee pain when practicing boxing. First of all, during the practice of boxing must always pay attention to the requirements of posture, such as loose hips, knee and toe direction to be consistent, etc.. Second, practice boxing slowly, relaxed practice. Mental tension can easily cause tension in action. Furthermore, at the beginning stage, you should pay attention to the right amount of exercise and improve gradually. The main reasons for knee pain: 1, the boxing practice process, the boxing frame under the plate does not meet the correct requirements, so that the knee stress. 2, the practitioner’s own lower limb muscle weakness, especially in the lack of endurance and control, resulting in knee sprain. 3.Exercise too much.