Effects of upper cervical manipulation on the electromyographic activity of the masticatory muscles and the opening range of motion of the mouth in women with temporomandibular disorder: randomized and blind clinical trial

ABSTRACT We evaluated the effects of upper cervical manipulation on the surface electromyographic activity (sEMG) of masticatory muscles and range of motion of the opening movement of the mouth in women with temporomandibular disorders (TMD). We evaluated 10 women with myogenic a TMD diagnosis, according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and divided randomly into an experimental group (EG) n=5, which received upper cervical manipulation, and a placebo group (PG) n=5, which received maneuvers without therapeutic effects. Five interventions were performed in both groups, once a week, with performance of pre-intervention assessments, post-immediate assessments (after 1st intervention) and post-delayed assessments (48 hours after the 5th intervention). The sEMG activity was processed using the root mean square and normalized by the peak value (RMS EMGn). We used for comparison the Student's t-test and ANOVA two-way repeated measures, adopting as significance the amount of 5%, and the Cohen d for treatment effect size. We found a significant interaction of group vs time (p