Stretch your knees with straight legs: when preparing, people sit on the bed or chair, and naturally straighten their lower limbs, and then stretch their knees as much as possible with the strength of their thighs. At this time, you can see that the hip bone moves towards the thigh with strength. Keep overstretching for a few seconds, and then relax. This is 1 time, 50 times in a row ×3, only once a day. Then gradually increase the number of times and finally keep it at 300×3.

"Ma bu" or "Ma bu" refers to the "Ma bu" in martial arts. Beginners can slide backwards against the wall, squat slowly, and try to keep their thighs level. Keep this posture 1-2 minutes and practice 1-2 times a day, but there are many adverse reactions. If you feel relaxed, you can keep your back away from the wall and do this for 1-2 minutes. Note that as long as your back is not on the wall, let the wall play a protective role; Don't go too far, lest you fall. Old people or people in poor health may not do this sport.

Exercise bike:

1. Before riding a bike, you need to prepare a comfortable and elastic garment, preferably elastic shorts, and then you need to prepare a pair of sports shoes with thick soles and relative air permeability, preferably a pair of riding gloves.

2. The height and position of the car should be correct, and the riding speed should not be too fast. It is recommended to wear protective pants to protect the lower body.

Note: If the knee itself is damaged, it is recommended not to choose the exercise mode of riding a spinning bike.