To perform Trigger Point Dry Needling (TPDN) a trained Physical Therapist inserts extremely thin, sterile, disposable needles into the muscles that are causing pain. The needles remain in the muscle only briefly and cause the muscle to contract and relax, decreasing discomfort. Sometimes the therapist will stimulate the needles with a slight electrical charge to increase the contract-relax effect. During TPDN you generally feel nothing more than a slight twitch in the muscle. Afterward, you usually feel significant relief from pain.