ANarrativeReviewofEffectsandUnderlyingMechanismsofNeedlingTherapyforTreatingMyofascialPainandMusculoskeletalDisorders

Musculoskeletal (MSK) disorders affect nearly 1.71 billion people worldwide and are the leading contributor to disability according to the World Health Organization. About 85% of low back pain and 30-85% of other MSK disorders are caused by myofascial pain. While traditional treatments like exercise, psychosocial interventions, and medications show effectiveness, the high prevalence of MSK disorders suggests additional treatment approaches are needed. Needling therapy (NT), including both acupuncture and dry needling, has gained popularity due to growing evidence of its effectiveness.

However, the mechanisms behind these treatments remain unclear and scattered across the literature, making it difficult for practitioners to understand how and why these treatments work.

The researchers conducted a narrative review to synthesize and categorize the effects and mechanisms of needling therapy for myofascial pain and MSK disorders. They searched four major medical databases (AMED, CLINAL, Cochrane Library, and Medline) from 2005 to 2025, looking for studies that reported effects or mechanisms of acupuncture or dry needling for treating myofascial pain or MSK disorders. They excluded studies involving wet needling (injection of substances) and focused only on dry needle insertion techniques. The review aimed to organize NT effects according to different anatomical levels of the human body and link each effect to its specific underlying mechanism using modern scientific terminology rather than traditional Chinese medicine concepts.

The review identified 27 studies and categorized four main effects of needling therapy based on anatomical levels: (1) Myofascial effect occurs at the muscle tissue level, where needling suppresses motor end plate activity by reducing acetylcholine release, breaking the cycle that creates trigger points; (2) Supraspinal effect happens in the brain, where needling activates the descending inhibitory system, releasing natural opioids that travel down the spinal cord to reduce pain perception; (3) Spinal effect occurs at the spinal cord level, where needling triggers presynaptic inhibition through the gate control mechanism, essentially "closing the pain gate" to block pain signals; (4) Local effect happens at the needle insertion site, where controlled micro-trauma triggers axon reflex, causing vasodilation and increased blood flow that promotes tissue healing.

This review provides practitioners with a scientific framework for understanding how needling therapies work, moving beyond traditional explanations involving "Chi" and "meridians" that are difficult to validate with modern science. By organizing the mechanisms into four clear categories based on anatomy, clinicians can better explain to patients why needling therapy might help their condition and make more informed treatment decisions. The review suggests that needling therapy works through multiple simultaneous mechanisms - reducing muscle tension at trigger points, activating the brain's natural pain control systems, blocking pain signals at the spinal cord, and promoting local tissue healing. This comprehensive understanding could help improve treatment outcomes and patient acceptance of needling therapies for myofascial pain and musculoskeletal disorders.