Dry Needling and Shoulder Muscle Blood Flow, Motions, and Pain Sensitivity in Individuals with Shoulder Pain

Shoulder pain is one of the most common reasons people consult with their primary health care provider, and 40-50% of these patients with shoulder pain continued to complain of persistent symptoms after 6 to 12 months. It has been suggested that the presence of myofascial trigger points (MTrPs) may contribute to the chronicity of shoulder symptoms. An MTrP is a hyperirritable taut band of tissue within a muscle that produces pain when stimulated MTrPs are common in patients with shoulder disorders and occur most often in the infraspinatus muscle of a painful shoulder MTrPs were associated with an acidic biochemical environment with elevated levels of inflammatory mediators, neuropeptides, and proinflammatory cytokines such as bradykinin and calcitonin g-related peptide. It was hypothesized that metabolic demands on muscle and capillary constrictions may contribute to the development of MTrPs. To date, only a few studies have examined the vascular environment of MTrPs and surrounding areas before and after dry needling. No studies have yet examined whether dry needling would change blood flow in patients with shoulder pathology. Therefore, the purpose of this pilot study is to examine the effect of dry needling on blood flow of the infraspinatus muscle using color Doppler imaging in individuals with shoulder pain. The secondary purpose is to examine the effect of DN on shoulder motion and sensitivity to pressure in individuals with shoulder pain.