In the human body, the skeleton rotates around the joint axis under the action of muscle tension, and its function is the same as that of lever. There are three forms of bone lever movement in human body:
1, balance bar: the fulcrum is between the stress point and the center of gravity. For example, head-up and head-down movements.
2. Labor-saving lever: the point of gravity action is between the fulcrum and the point of force action. For example, the action of raising the heel when walking, this lever can overcome the heavy weight.
3. Speed lever: the point of force is between the point of gravity and the fulcrum. Such as the activity of elbow joint, this activity must overcome the smaller gravity with greater strength, but the movement speed and amplitude are very large.
Extended data:
Precautions:
1, the amount of exercise should not be too large at a time, and attention should be paid to gradual progress, from easy to difficult, from less to more, from light to heavy.
2. According to the user's physical condition, control the appropriate amount of exercise and stick to it for a long time.
3. Be prepared, relax and prevent injury and muscle strain.
4. The number of push-ups should be 20 per minute, and the total number can be about 30. You can add it slowly. Do more and more in the future.
5. At the same time, standard push-ups are not recommended. You can choose high push-up exercises, that is, practice on the wall, with your feet shoulder-width apart, one arm off the wall, standing on the wall, and your palms on the wall, and then do elbow flexion and extension exercises.
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