Dry needling is a method of using a fine acupuncture style needle in the clinical management of muscular pain by inactivating Trigger Points, including neural and biochemical effects that can contribute to pain relief.
Key Features of Myofascial Trigger Points
A tight band within a muscle
Local and referred pain
Decreased range of motion
Lack of muscle endurance
Decreased blood flow
Causes of Trigger Points
There is a general agreement that the most common reason for the development of trigger points are muscle overload, such as sustained low level muscular contractions or direct trauma.
Trigger points may develop during sport, occupational or recreational activities when a muscles capacity to adequately recover is exceeded.
Dry needling techniques may also be used to target joints, fascia, tendons, scar tissue and sports injuries.
Acupuncture and Dry Needling
These two treatment terms are often confused and used interchangeably. Acupuncture is firmly based in Traditional Chinese Medicine (TCM), whereas Dry Needling is based on a Western Biomedical model.
Dry needling requires extensive training and practice including a firm knowledge of anatomy in order to develop the sensitivity and appreciate subtle changes in tissue compliance to find and deactivate trigger points.
There is a large body of research on the effects of dry needling. Level 1 evidence suggests that dry needling is more effective than sham or placebo for a large range of musculoskeletal conditions.
The local reduction in the pain threshold with an increase of responsiveness by peripheral pain fibers (nociceptors) is termed as peripheral sensitization.
Myofascial trigger points are not merely a peripheral phenomenon, nociceptive input from MTP’s leads to effective segmental sensitization and hyper-excitability of dorsal horn neurons in the spinal cord (Mense 2010) Researchers (Hong et al 1996) found that pressure sensitivity is higher in the Trigger Point site than at other control points in the muscle.
Findings revealed a local concentration of bio-chemicals that increase pain sensitivity such as (substance P, CGRP, Tumor necrosis factor, Interleukins 6 & 8, 5-HT and nor-epinephrine), these were all higher in the MTP’s zone compared to control points (Shah et al 2005).
These pain-producing chemicals may be released from the locally sensitized nerve fibers (nociceptors) but also from the muscle contraction within the tight band (Gerwin 2008).
Local Twitch Response (LTR)
When a clinician strums across active muscle fibers and it responds with a sudden reflex contraction, it is called a Local twitch response. The LTR has been correlated with the degree of sensitization within the muscle. Eliciting an LTR with needling has shown to have a positive therapeutic effect in releasing the local tension and downgrading the concentration of pain producing chemicals.
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Dommerholt J, C Fernandez-de-las Peñas. 2013. Trigger Point Dry Needling. An Evidence and Clinical-Based Approach. Churchill Livingstone.
Gerwin R.D. 2008. The taught band and other mysteries of the trigger point: An examination of the mechanisms relevant to the development and maintenance of the trigger point. Journal of Musculoskeletal Pain 16, 115-121
Hong C.Z. 1996. Pathophysiology of myofascial trigger points. J. Formos. Med Assoc. 95, 93-104.
Mense S, Simons G. 2001. Muscle Pain. Understanding its Nature Diagnosis, and Treatment. Lippincott, Williams and Wilkins
Mense S. 2010. How do muscle lesions such as latent and active trigger points influence central nociceptive neurons? Journal of Musculoskeletal Pain.
Shah JP, Phillips TM, Danoff JV, Gerber LH. An in vivo micro analytical technique for measuring the local biochemical milieu of human skeletal muscle. J Appl Physiol. 2005; 99(5): 1977–84
Simons D, Travell JG, Simons LS.1999. Myofascial pain and dysfunction. The trigger point manual. Upper half of body. 2.: Lippincott, Williams and Wilkins.