RESUMEN
OBJECTIVE: The objective of this study was to compare trigger point (TrP) dry needling, TrP electroacupuncture and motor point electroacupuncture of the trapezius muscle for the treatment of myofascial pain syndrome (MPS). METHODS: This randomised clinical trial included 90 patients divided into three groups. Group 1 was treated with dry needling of TrPs, group 2 with intramuscular electrical stimulation of TrPs, and group 3 with electroacupuncture of motor points and/or the spinal accessory nerve. Each group received seven treatment sessions. The outcomes were the pain score measured by visual analogue scale (VAS) and quality of life evaluated by the 12-item short form (SF-12) health questionnaire. We compared the pain outcome over serial time points using growth curve analysis methods. RESULTS: Participants in the three groups experienced significant improvements in pain scores over time. The average pain level of participants in group 3 across the repeated assessments was 0.98 units lower than in group 1 (mean difference (95% confidence interval (CI) = 1.74-0.23)), p = 0.012). There were no significant differences in pain scores between participants in groups 1 and 2, and there were no significant differences in quality of life across the three groups at the end of the treatment period. CONCLUSION: Our results provide evidence that electrical stimulation of motor points and/or of the spinal accessory nerve may be superior in terms of pain relief (but not quality of life) to dry needling and possibly electrical stimulation of trigger points for the management of MPS involving the trapezius. TRIAL REGISTRATION NUMBER: TRIAL-RBR-43R7RF (Brazilian Clinical Trials Registry).