A myofascial trigger point is a hyper-irritable spot within a skeletal muscle, often felt as a small, firm knot or taut band of muscle fibers. This localized contraction is a tiny area of muscle that remains chronically contracted, unlike a typical muscle spasm. Trigger points cause localized pain and tenderness, and they can also cause pain that radiates to distant parts of the body. Treatment techniques like manual therapy or dry needling aim to release this contracted area to alleviate the associated pain and dysfunction.
The Physical Mechanism of Release
The sustained contraction of a trigger point is often explained by the “energy crisis” model, where a localized section of muscle fibers is unable to relax. This microscopic contracture is driven by an abnormal, excessive release of the neurotransmitter acetylcholine, causing the muscle fiber segments (sarcomeres) to shorten and stay locked. The continuous contraction severely compresses local blood vessels, restricting blood flow. This vascular compression creates oxygen deprivation (localized ischemia), preventing muscle cells from producing the energy molecule adenosine triphosphate (ATP) necessary for relaxation.
The lack of oxygen and ATP prevents the muscle from efficiently removing calcium ions, leading to a buildup of metabolic waste products and inflammatory mediators. These accumulated chemicals irritate local pain receptors (nociceptors), generating the tenderness and referred pain characteristic of a trigger point. When pressure is applied, the mechanical stimulus forces the contracted sarcomeres to lengthen, interrupting this vicious cycle. This action causes a temporary increase in blood flow (vasodilation) into the formerly restricted area. This influx of fresh, oxygenated blood flushes out the accumulated chemicals, allowing the muscle tissue to regain the metabolic capacity to relax.
Immediate Sensory and Systemic Reactions
One of the most distinct physical signs of an effective release, particularly with dry needling, is the local twitch response. This is a quick, involuntary contraction of the muscle fibers that occurs when mechanical stimulation contacts the trigger point. The twitch is thought to be the abrupt depolarization of the abnormal motor endplate, signaling the disruption of the sustained contracture. Experiencing this twitch often correlates with a greater immediate reduction in pain intensity.
As pressure is applied, the patient commonly feels the referred pain pattern associated with that specific trigger point. The pain may seem to travel or spread away from the treatment site, which is a temporary but important confirmation that the practitioner has located the correct hyper-irritable spot. This referred sensation typically dissipates quickly once the technique is complete. The body’s nervous system also reacts systemically to the sudden shift in muscle tension and pain input.
Some individuals may experience temporary systemic effects, known as an autonomic response, suggesting the nervous system is transitioning from a stressed state. These reactions can include sudden flushing or warmth in the skin, temporary lightheadedness, or involuntary yawning. An immediate, temporary increase in heart rate can also occur as the body adjusts to the change in muscle tone. These responses are transient and represent the body’s shift toward a more relaxed physiological state.
Post-Release Recovery and Care
Following the release of a trigger point, the treated area often feels noticeably sore, similar to the deep ache felt after an intense workout. This post-treatment soreness is a normal inflammatory response to the mechanical disruption of the tight tissue. The discomfort generally peaks within 12 to 24 hours and typically resolves entirely within 48 hours.
The muscle needs time to adapt to its newly achieved, relaxed resting length and restored circulation. Proper self-care is important for maximizing treatment benefits and minimizing lingering soreness. Staying well-hydrated helps the body flush out the metabolic byproducts released into the bloodstream.
Applying gentle heat, such as a warm compress or bath, assists in maintaining improved blood flow to the area. Gentle, non-strenuous stretching of the treated muscle is recommended to encourage the muscle fibers to retain their new, longer state. While some relief may be felt immediately, the full therapeutic effect is often a gradual process as the muscle tissue heals and the nervous system calms down.