What is Dry Needling?
By: Brice Heinen, PT, DPT, Cert. DN
Tools and Techniques
How is it different than acupuncture?
While the needle is the same in both disciplines, the theory is not. Dry Needling is part of modern Western medicine principles, and supported by clinical research with insertion directed at anatomical points to stimulate physiological and mechanical reactions. Acupuncture is traditional Eastern medicine with the goal of regulating the flow of qi and blood by making “holes” along pathways or meridians of the body2.
What does Dry Needling do?
Intramuscular insertion of dry needling is often aimed at trigger points or TrP’s. Trigger points are hyperirritable spots found in taught bands of skeletal muscle that are identifiable by palpation as being localized, hard, and produce local/refereed pain upon compression1,3, 4. They are categorized as active trigger points: larger, decreased circulation, significantly lowered pH, and spontaneously painful; or latent trigger points: painful upon palpation and alter muscle activation patterns during AROM4, 5. Both active and latent TrPs present with local ischemia and hypoxia.
Factors contributing to trigger point development mechanically include increased muscle fiber contraction and recruitment, or injury, which leads to capillary constriction with resultant ischemia and increased metabolic demand causing pain. This is usually in response to muscle overload from repetitive and prolonged muscular contractions6. Physiologically, an increase in acidic pH, acetylcholine, CGRP, cytokines, inflammatory mediators, and neuropeptides increases motor end plate noise and the stimulation of nociceptiors6, 7.
Dry needling of trigger points has been shows to elicit a local twitch response that reduces the presence of nociceptive and inflammatory chemicals, relaxes taught bands, alleviates local and referred pain, improves ROM, normalizes pH, and returns circulation4.
Insertion into musculotendinous junctions is often for the same reasons as at trigger points, intramuscular pressure and damage increases significantly at muscle origin and insertions with low-level concentric and sustained eccentric contractions potentially leading to similar environments6,7. Stimulation of tendons or osteotendinous junctions has been shown to increase collagen proliferation, promoting blood flow through vasodilation, and increase oxygen saturation levels9.
Insertion into osteoligamentous junctions or “periosteal pecking” stimulates large A delta fibers blocking pain signals by irritating the periosteal nerve endings which arouses pain inhibiting mechanisms in the central nervous system8. Twisting the needle results in fibroblasts realigning in a lamellar shape, increasing collagen synthesis, and cell proliferation that remodeling scar tissue and fascia4. Peri-neural stimulation has been shown to reduce pain, improve sensory and motor conduction velocities, as well as stimulate microcirculation in mild to moderate carpal tunnel syndrome9.
Is it effective?
While not appropriate for every patient, Dry Needling has been shown to reduce endplate noise at TrPs, improve local circulation, reduce TrP pain sensitivity, and improve ROM4, 5. Diagnoses treated include radiculopathies, joint dysfunction, disk pathology, tendonitis, temporomandibular dysfunction, migraines, carpal tunnel syndrome, postural/whiplash injuries, and spinal dysfunction4. After a throughout physical therapy evaluation and along with other manual and neuromusculoskeletal interventions, dry needling can be effective at alleviating pain and dysfucntion returning patients to a restriction free lifestyle.