With acupuncture the premise was to treat an acupoint along the meridian; with biomedical dry needling it is to treat local muscle trigger point and area of dysfunction. A local area of dysfunction can prevent proper function and guarding when the muscle fibers do not contract or relax properly in that muscle belly. When this happens that is what is known as a Trigger Point or an area of focus that causes pain to originate and refer out to different regions when formed. When a needle is placed in a trigger point or along a knot in the muscle that knot or trigger point releases in what is felt as a muscle twitch response and allows the muscle to contract and extend meaning function properly after the twitch response.