Effects of Vocalization on Upper Extremity Muscle Activity during Reaching Task in Patients with Hemiplegia

Abstract

This study examined the effects of vocalization on upper extremity muscle activity during reaching task in patients with hemiplegia. Thirteen persons with right brain stroke performed reaching to a cup under four concurrent speech conditions of vocalizing the word "Ah" with hemiplegic side. These four conditions are self-vocalization, external vocalization, imaginary vocalization, and no vocalization. The muscle activity(Biceps brachii, Triceps brachii, Middle deltoid, and Upper trapezius) were measured using MP150. Muscle activity was significantly higher under self-vocalization and external vocalization conditions compared to the muscle activity under imaginary vocalization and no vocalization conditions on triceps brachii muscle.(p<0.05). Triceps brachii muscle was highly correlated with biceps brachii muscle(r=0.777, p<0.05). The results suggest that self-vocalization and external vocalization can be used in facilitating upper extremity movements in patients with stroke. When working with patients with right hemispheric stroke, therapists might explore possibilities of using patient's self-speech to enhance the quality of upper extremity movement performance.