The effect of glenohumeral sustained glide on scapular muscle activity ratio in asymptomatic individuals

Sustained postero-lateral glide at the glenohumeral joint is a manual therapy technique used for treating patients with shoulder pain. The aim of this study was to assess the effect of sustained glide on scapular muscle activity ratio. We used surface electromyography to monitor activity of three scapular muscles: upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA). Participants performed 10 repetitions of shoulder abduction at baseline, intervention and follow-up. At baseline and follow-up, there was not glide applied to the shoulder. During intervention, a clinician administered the sustained glide. Muscle activity levels were measured at baseline, intervention and follow-up time points. A univariate model for repeated measures of analysis of variance was used to assess differences in scapular muscle activity ratio (UT/LT, UT/SA and LT/SA) between each time point. Our findings suggest there were no differences in ratio of scapular muscle activity between time points.