Chengshan is an acupoint on the bladder meridian, and the effects and benefits of tapping Chengshan are to help relieve localized pain, abdominal pain, and some conditions of the anus, among other things. Chengshan is located at the back of the calf. When you straighten your calf, you can see the two muscle bellies of the gastrocnemius muscle, and the intersection of the muscle bellies and tendons is where the point is located. Tapping Chengshan acupoint can have the effect of stimulating the acupoint, which is useful for localized pain as well as constriction of the waist and legs; it is also useful for some diseases of the anus, such as hemorrhoids and constipation. In addition, it can also be used to relieve pain in the abdomen, hernia pain and so on. Tapping Chengshan acupoints should be moderate in strength, and too much force can easily cause spasm of the gastrocnemius muscle. Tapping Chengshan acupoints need to be guided by a doctor, do not operate blindly on your own.