The functional activities of limbs, including the movements of joints, bones and muscles, are dominated by the liver and kidney.

Therefore, there is a saying that "the kidney dominates the bone, and the bone is the kidney". People who are good at keeping in good health should insist on physical exercise in winter, so as to achieve the effects of nourishing tendons and strengthening the kidney, relaxing tendons and activating collaterals, dredging qi and enhancing their own resistance, thus achieving the purpose of tonifying kidney and strengthening the body.