DRY NEEDLE STIMULATION OF MYOFASCIAL TRIGGER POINTS EVOKES SEGMENTAL ANTI-NOCICEPTIVE EFFECTS

摘要

Objective: To test the hypothesis that dry needle stimulation of a myofascial trigger point (sensitive locus) evokes segmen-tal anti-nociceptive effects. Design: Double-blind randomized controlled trial. Subjects: Forty subjects (21 males, 19 females). Methods: Test subjects received intramuscular dry needle puncture to a right supraspinatus trigger point (C_(4,5)); controls received sham intramuscular dry needle puncture. Pain pressure threshold (PPT) readings were recorded from right infraspinatus (C_(5,6)) and right gluteus medius (L_(4,5)S_1) trigger points at 0 (pre-needling baseline), 1, 3, 5,10 and 15 min post-needling and normalized to baseline values. The supraspinatus and infraspinatus trigger points are neuro-logically linked at C_5; the supraspinatus and gluteus medius are segmentally unrelated. The difference between the infraspinatus and gluteus medius PPT values (PPT_(seg)) represents a direct measure of the segmental anti-nociceptive effects acting at the infraspinatus trigger point. Results: Significant increases in PPT were observed in test subjects at 3 (p=0.002) and 5 (p=0.015) min post-needling, compared with controls. Conclusion: One intervention of dry needle stimulation to a single trigger point (sensitive locus) evokes short-term segmental anti-nociceptive effects. These results suggest that trigger point (sensitive locus) stimulation may evoke anti-nociceptive effects by modulating segmental mechanisms, which may be an important consideration in the management of myofascial pain.