The immediate effect of dry needling on multifidus muscles' function in healthy individuals

BACKGROUND: Dry needling of muscles is mainly used for the management of pain in musculoskeletal disorders. Yet, the association between dry needling and motor performance of muscles is still unclear. OBJECTIVE: To investigate the immediate effect of dry needling on lumbar multifidus muscles' function in healthy subjects. METHODS: Twenty-eight volunteers were divided randomly into: study group (13 subjects) and control group (15 subjects) who underwent no intervention. Study group received dry needling to the lumbar multifidus muscles using a deep insertion technique with 4 needles (2 on each side of the spine). The needles were left in situ for 10 minutes. Ultrasound imaging was used to measure multifidus muscles' thickness, pre and post-procedure during rest in a prone position and during contralateral active straight leg extension. RESULTS: Significant difference was found in the percentage of change of muscle activation post needling between groups on the right side at level L4-5. A slight increase in the percentage of muscle activity, post procedure was observed in the dry needling group compared with the control group, although not significant in other segments examined. CONCLUSION: An improvement of back muscle function following dry needling procedure in healthy individuals was found. This implies that dry needling might stimulate motor nerve fibers and as such increase muscle activity.