The side effects of playing closed needle, there are two main aspects: 1, closed needle inside the drug is mainly hormones and anesthetics, commonly used is prednisolone acetate, lidocaine hydrochloride injection, these hormones and anesthetics can effectively reduce local inflammatory edema, control inflammation, reduce the sense of pain. But it belongs to the treatment of symptoms but not the root cause, only to reduce the symptoms, but not to promote the injury or strain of the location of healing, will lead to anesthetic and hormone effects after the retreat, the pain may still appear. Sometimes excessive activity after pain relief will lead to further aggravation of the location of the injury, resulting in more obvious symptoms after the effect of drugs. 2, resulting in injury to the location of muscle, tendons, ligaments and other structural elasticity decline, toughness decline, become more fragile, because of closed injection and long-term local non-healing, will lead to the gradual hardening of these soft tissues, elasticity decline, in some power stretching, will lead to further aggravation of the location of the injury. will lead to further aggravation of this location damage.