The effects of transcutaneous electrical nerve stimulation on muscle activity pattern in professional voice users with muscle tension dysphonia using surface electromyography data: A pilot study.

ABSTRACT

OBJECTIVES: Muscle Tension Dysphonia is a voice disorder, which results in stiffness in the laryngeal extrinsic muscles, intense collision, painful contractions, and vibrations of the vocal cords. Due to the multifactorial identity of Muscle Tension Dysphonia, its therapeutic approach must be multidisciplinary. METHODS: The participants were divided into two groups a control group (5participants) that received Circumlaryngeal Manual Therapy (CMT) + Placebo Transcutaneous Electrical Nerve Stimulation and an experimental group (5participants) that received Transcutaneous Electrical Nerve Stimulation + CMT. Both groups received 10 sessions of treatment, twice a week, for 40 min each. Before and after treatment, participants were assessed using the Dysphonia Severity Index (DSI) and surface electromyography for their ability to sustain the vowels /e& u/and count from 20 to30. RESULT: After therapy, there were substantial improvements in the DSI (2.72 ± 0.55, P < 0.05) and muscle electrical activity in the control group. The DSI (3.66 ± 0.63, P < 0.05) and muscle electrical activity were also significantly improved in the experimental group after treatment. The findings of the between-group comparison after treatment revealed a significantly greater increase in the Dysphonia Severity Index in the experimental group compared with the control group (P = 0.037). Although there was no significant difference between the two groups in terms of muscle electrical activity, clinically significant changes were more noticeable in the experimental group when compared with the control group. CONCLUSIONS: Positive results were seen in both groups. The results demonstrate that both approaches relax vocal tract muscles. As a result, Transcutaneous Electrical Nerve Stimulation was recommended as a complementary treatment for clients with Muscle Tension Dysphonia.