A. Lie flat on the bed with the pelvis backward, hold your right foot with both hands, keep your hips on the ground 15 seconds, repeat the action with your left leg, and keep your feet bent for 30 seconds.
B. Sit on the bed, stretch your knees back, put your knees together, and lie still with your hands behind your head for two minutes. Step by step according to your own situation can increase your time.
C. Lift your hips and extend your feet to the ground, place the book between your feet, and keep your shoulders, hips and knees in a straight line for three minutes.
D. Stretch the left leg to the ground, stretch the right leg backwards with the back, hold the right foot with the right hand and bend it to the hip for 30 seconds, and change the left leg to repeat the action.