RESUMO
BACKGROUND: There is a relationship between low back pain (LBP) and central nervous system dysfunction. Needling therapies (e.g. acupuncture, dry needling) are proposed to impact the nervous system, however their specific influence is unclear. PURPOSE: Determine how needling therapies alter functional connectivity and LBP as measured by functional magnetic resonance imaging (fMRI). METHODS: Databases were searched following PRISMA guidelines. Studies using fMRI on individuals with LBP receiving dry needling or acupuncture compared to control or sham treatments were included. RESULTS: Eight studies were included, all of which used acupuncture. The quality of studies ranged from good (n = 6) to excellent (n = 2). After acupuncture, individuals with LBP demonstrated significant functional connectivity changes across several networks, notably the salience, somatomotor, default mode network (DMN) and limbic networks. A meta-analysis demonstrated evidence of no effect to potential small effect of acupuncture in reducing LBP (SMD -0.28; 95% CI: -0.70, 0.13). CONCLUSION: Needling therapies, like acupuncture, may have a central effect on patients beyond the local tissue effects, reducing patients' pain and disability due to alterations in neural processing, including the DMN, and potentially other central nervous system effects. The meta-analysis should be interpreted with caution due to the narrow focus and confined sample used.
RESUMO
BACKGROUND: Needling has been shown to decrease pain in the short term; however, its effects on muscle force production are unclear. OBJECTIVE: To evaluate the evidence regarding the comparative effects of needling on muscle force production. METHODS: In this systematic review, an electronic search was performed using key words related to needling. Methodological quality of articles was appraised and effect sizes were calculated. The strength of evidence was determined, and meta-analysis was performed when similar methods were used in studies for similar conditions. RESULTS: Twenty-one studies were included in this review, of which 9 were deemed to be of high quality (greater than 6/10 on the Physiotherapy Evidence Database [PEDro] scale), 11 of fair quality (5 to 6/10), and 1 of poor quality (less than 5/10). Three meta-analyses were performed. There was moderate strength of evidence and medium effect sizes for needling therapy to enhance force production in those with neck pain, and very low strength of evidence of no effect for individuals with nonspecific and postoperative shoulder pain and those with lateral epicondylalgia. Other studies not included in the 3 meta-analyses demonstrated no significant effect of needling on force production. These studies included individuals with carpal tunnel syndrome, knee osteoarthritis, ankle sprains, knee arthroscopy, or delayed-onset muscle soreness. CONCLUSION: The majority of studies suggest no effect of dry needling on force production. High-quality studies with adequate power that control for the placebo effect and follow accepted reporting standards could make valuable contributions to the literature. This study was registered with the International Prospective Register of Systematic Reviews (PROSPERO, CRD42017080318). LEVEL OF EVIDENCE: Therapy, level 1a. J Orthop Sports Phys Ther 2019;49(3):154-170. Epub 30 Nov 2018. doi:10.2519/jospt.2019.8270.