Surface electromyographic biofeedback for behavioral dysphonia in adult people: a systematic review

ABSTRACT Purpose To review systematically the literature and to analyze the effectiveness of surface electromyographic biofeedback in the rehabilitation of adults with behavioral dysphonia. Research strategies Two authors performed an independent search in the following databases: Clinical Trials, Cochrane Library, Embase, LILACS, PubMed, and Web of Science. A specific search strategy was developed for each database. Selection criteria The review included studies that examined the effectiveness of surface electromyographic biofeedback compared to other direct vocal therapy intervention in adults with behavioral dysphonia. There were no restrictions in regard to language or date of publication. Data analysis Analysis of the risk of bias, heterogeneity, quantitative and qualitative data, sensitivity, subgroups, and publication bias. Results 51 studies were identified, but only two cohort studies remained as prospects for analysis. The studies showed 100% uncertain risk of selection, performance, and detection bias. There was a high degree of clinical heterogeneity. The descriptive analysis showed a reduction in muscle electrical activity and improvement in vocal self-assessment using electromyographic biofeedback; however, it was not possible to calculate the effect size of the interventions. The present study was limited by the fact that it was unable to show a consensus for the majority of data analyzed. Conclusion The available literature does not support a conclusive finding about the effectiveness of surface electromyographic biofeedback compared to other direct interventions used in the rehabilitation of adults with behavioral dysphonia. The studies analyzed vary widely in their clinical procedures and methodology, making it impossible to determine the procedure's effectiveness