Determine the effect of dry needling using a 32 gauge needle on active trigger points in subjects with chronic myofascial pain.

Participants will receive treatment for active trigger points (3 on successive weeks) and will have pain, status of the trigger point and functional measures assessed at baseline, after treatment and eight weeks later.

Chronic myofascial pain syndromes, such as pain associated with myofascial trigger points (MTrPs), are prevalent yet poorly understood. Our long-term goal is to determine the pathogenesis and pathophysiological mechanisms of chronic pain associated with trigger points, eventually leading to the development of objective diagnostic criteria and effective pain management strategies. We propose to achieve this goal using a new and unique integrative methodology combining microanalytic biochemical assays, ultrasound technology (imaging) and mathematical modeling. An additional component of the study plan is to learn if a standard treatment for MTrPs is associated with the biochemical and ultrasound changes we will be measuring This project has the following specific aims: 1) To understand the viscoelastic soft tissue neighborhood and vascular physiology of affected muscle at a macroscopic level using ultrasound imaging, elastography and Doppler blood flow imaging; 2) To understand the pathophysiology of myofascial trigger points at a nanotechnological level through assays of biochemical milieu using a microdialysis technique; 3) To develop mathematical models of underlying pathophysiological mechanisms based on experimental observations for quantitative hypothesis testing; 4) To determine if dry needle therapy, a standard of care for MTrPs, changes the macroscopic and/or microscopic measurements and leads to resolution of the trigger point and secondarily associated pain symptoms.. Our hypothesis is that pathogenesis of myofascial pain syndrome involves local trauma to the muscle fibers, and the biochemical response to the injury leads to sustained muscle contracture, compression of blood vessels and a local energy crisis that causes tissue hypoxia and the expression of pain-producing substances at myofascial trigger points. Relieving the trigger point through dry needle therapy

Inclusion Criteria:

• spontaneous soft tissue pain in shoulder and neck region

Exclusion Criteria:

• recent fracture, neurological injury or history of stroke, use of opioids