Dry Needling Alters Trigger Points in the Upper Trapezius Muscle and Reduces Pain in Subjects With Chronic Myofascial Pain

Myofascial pain syndrome (MPS) is a common condition affecting 15% of general medical visits, causing significant functional limitations and reduced quality of life. While dry needling is frequently used to treat active myofascial trigger points (MTrPs), the relationship between pain reduction and changes in trigger point status has never been studied systematically. This research addresses a fundamental question in myofascial pain treatment: does successful dry needling both reduce pain and change the physical characteristics of trigger points?

Researchers conducted a prospective study of 52 adults with chronic neck/shoulder pain lasting more than 3 months and active trigger points in the upper trapezius muscle. Participants received three weekly dry needling treatments targeting a single active trigger point. Two experienced clinicians with demonstrated inter-rater reliability performed all evaluations and treatments using standardized techniques. Pain was measured using three different tools: visual analog scale (VAS), Brief Pain Inventory (BPI), and pressure pain threshold (PPT).

Trigger points were classified as active (spontaneously painful), latent (painful only when pressed), or resolved (no palpable nodule). Secondary measures included cervical range of motion, mood questionnaires, and disability assessments.

The results were striking: 41 of 52 participants (79%) showed improvement in trigger point status from active to either latent or completely resolved. Pain reduction was significant across all measures, with VAS scores dropping by an average of 2.87 points in responders versus only 1.00 points in non-responders (p<0.001). The Brief Pain Inventory scores improved significantly in responders but not non-responders. Cervical range of motion improved, particularly rotational asymmetry and side-bending.

Participants also showed significant improvements in mental health, physical functioning, and disability scores. The study demonstrated a clear correlation between trigger point status change and pain reduction.

This landmark study provides the first objective evidence that dry needling not only reduces pain but actually changes the physical status of trigger points. The findings support the theory that trigger points are legitimate treatment targets, not just areas to needle for pain relief. For patients, this means dry needling offers both immediate pain relief and lasting structural changes to problematic trigger points. For clinicians, the study validates the importance of targeting specific trigger points and suggests that successful treatment should result in both pain reduction and trigger point resolution.

The research also highlights the value of using multiple pain assessment tools and tracking objective changes in trigger point status to evaluate treatment success.