Static stretching exercises, as the name implies, refer to stretching exercises with constant posture. There is only one lacing action or posture in the whole process, and then it is maintained for a certain time. The practice of static lacing is to make the muscles (or muscle groups) that want to stretch under certain stretching pressure through a certain lacing posture. Antagonistic muscle group and active muscle group are in a relaxed state; Then apply pressure to the muscles (or muscle groups) to be stretched. Then keep this posture for a while and stretch the target muscle group. During static stretching, it takes at least 20 seconds for muscles to relax and start stretching, and the effect begins to weaken after 45 ~ 60 seconds. Static lacing is very safe and effective, with almost no risk of injury. It is a good choice for beginners and people who don't like sports. Passive (or auxiliary) lacing is very similar to static lacing, but it needs the help of a companion or auxiliary equipment. Because of the intervention of external force, the muscles are stressed, so the risk of this stretching exercise is slightly higher than the first one. Remind you, you must choose solid auxiliary equipment. In addition, when you have a partner to help you, never push too hard or suddenly. Remember to choose your partner carefully, because when doing this stretching exercise, the safety of muscles and joints is completely in the hands of your partner. Passive stretching helps to further expand the range of motion of muscles and joints, but the risk will be higher. This stretching method is a good choice for rehabilitation and relaxation exercise. The active lacing and stretching movement does not need the help of external forces such as instruments or companions. This tendon stretching method uses the strength of the opposite muscle (antagonistic muscle) to stretch the target muscle group (active muscle). Antagonistic muscle contraction can help the relaxation of active muscles. The most typical action is to lift one foot forward as far as possible without the assistance of peers and instruments, and keep this posture for a period of time.