First, double upper limb stretching training. Standing position, hands together behind the body, both upper limbs straight, backward and upward, parallel to the ground, when the back and both upper limbs feel a significant pull. Hold for 5 seconds, slowly put down. Second, double lower limb stretching training. Sitting, one side of the lower limbs straight, the other side of the flexion, the palm of the foot on the side of the straight leg, hands on the knee, the body bent forward, pulling the straightened side of the lower limbs. Both sides alternately. Third, back stretching training. Prone position, both lower extremities together, both upper extremities backward, outward extension, lumbar back force, lift the back of the neck off the ground. Stretch the low back muscle groups.