The effect of expiratory muscle strength training (EMST) on expiratory and submental muscle activity : a study of individuals with Parkinson’s disease

Abstract

This is a preliminary study investigating the effect of expiratory muscle strength training (EMST) on expiratory and submental muscle activity, and its relationship with speech and respiratory functions in individuals with Parkinson’s disease. Eleven adult participants were randomly assigned to the experimental group and the control group. Activity of expiratory and submental muscles, voice handicap index (VHI) score, respiratory and speech functions were measured before and after treatment. The EMST group was provided with EMST training using a device with a training load of 70% of the participant’s averaged maximum expiratory pressure, whereas the control group used a spirometry. Both groups followed the 5 x 5 x 5 protocol, providing training 5 days per week with 5 sets of 5 repetitions per day. Preliminary results revealed significant improvement in maximum phonation time and vocal loudness in both treatment groups. Significant between-group difference with respect to changes in rectus abdominis muscle activity during sustained vowel production and in VHI physical subscale score were demonstrated. These findings indicate that both respiratory muscle trainings improved speech performance. Nonetheless, EMST has its potential to induce physiologic changes in expiratory muscles and hence, improve the physiology of the respiratory mechanism to achieve speech function gains.