Electromyography of neck and shoulder muscles in instrumental musicians with musculoskeletal pain compared to asymptomatic controls: A systematic review and meta-analysis.

Musicians report a high prevalence of annual musculoskeletal pain (86-89%), attributed to prolonged playing times consisting of repetitive static and dynamic muscle activity. The aim of this study was to explore, compare and synthesise evidence on electromyographic (EMG) muscle activity in neck, shoulder and spinal musculature between painful and asymptomatic instrumental musicians. Ovid, Wiley, Web of Science and Scopus databases were searched in August 2016 for cross-sectional studies that compared EMG activity of neck, shoulder and spinal musculature between musicians with musculoskeletal pain and asymptomatic comparisons. An updated search was performed in May 2017, adding a further study. Two authors independently assessed papers for inclusion and then quality, determined using a modified Downs and Black Checklist. Means and standard deviations were extracted from each study to calculate effect sizes and compare results. Six studies were found to fulfil inclusion criteria. Five studies were deemed high-quality with one being low-quality. Conflicting evidence was found supporting increases in upper trapezius EMG muscle activity in musicians reporting of pain. Moderate-quality evidence indicates increased SCM activity in musicians reporting pain. There was limited evidence supporting increased activity of deltoids, lower trapezius and the upper cervical extensors in musicians reporting of musculoskeletal pain. Meta-analysis of results of three studies assessing upper trapezius activity were conflicting with these not being statistically significant. Further studies with prospective designs, larger population sizes and on broader instrumental groups are warranted.