The pain on the back of the thighs may be caused by lactic acid accumulation, which can be stretched by means of leg press, forward body flexion and seated forward body flexion to promote the consumption of lactic acid and relieve the pain. 1. Leg press: You can stretch the back of your thighs by pressing your legs. When you press your legs, keep one leg in front of the other, keep the other leg bent at the knee, and press your hands on the leg that is bent at the knee, and pay attention to the fact that you need to press both legs alternately. 2. Bending forward: when standing, let the legs open slightly, keep the legs in an upright state, the upper body bends down to the patient’s hands can touch the ground. 3. Seated forward bending: when sitting, keep the legs straight and bend down, touch the ankle or toe area with both hands. The pain in the back of the thigh may also be related to muscle strain, cold, etc. At this time, attention should not be stretched to avoid aggravating the strain. Whether you can stretch or not should be decided according to your doctor’s advice. If the pain in the back of the thigh persists, you should go to the hospital for examination and treatment.