Stand on one leg, bend your knees 90 degrees, continue to bend your knees and lift your calves, and then return to the posture of bending your knees 90 degrees, 3 groups a day, each group 10 times. Note that in the late stage of exercise, the runner will tie a sandbag to his ankle and carry out leg lifting exercise with weight within the tolerable range of pain. 2) Resistance to knee bending?

Keep your back upright and your knees bent 90 degrees; Tie one end of the elastic band to a fixed post or object, and the other end to the right ankle; Keep your body stable and bend your right leg backwards; Repeat 15-20 times. Repeat the above actions on the other side. It is recommended to exercise 2~3 groups a day, each group 15~20 times, 2 days a week.