The Effect of Exhalation Breathing Exercise on Respiratory Synergist Muscle Activity and Pulmonary Functions in Patients with Forward Head Posture

Purpose: The aim of this study is to suggest an intervention method for clinical use in the future by analyzing the effect of breathing exercise on activity of sternocleidomastoid muscle and scalenus anterior muscle, which are respiratory synergist muscles, and pulmonary functions in patients with forward head posture. Methods: Prior to the experiment, 12 patients (experimental group) performed feedback exhalation exercise along with conventional deep neck exercise, and 11 subjects (control group) performed feedback deep neck exercise along with conventional deep neck exercise. The intervention programs were performed for 40 minutes once a day (three times a week for four weeks). Results: Before intervention, %RMS was measured for surface electromyography (sEMG), and FVC, FEV1, and FEV1/FVC were measured using a spirometer. After four weeks, these items were re-measured under the same condition and analyzed. In within-group comparison of the experimental group, activity of sternocleidomastoid muscle and scalenus anterior muscle showed a significant decrease (p<0.05) (p<0.001), and forced vital capacity (FVC) showed a significant increase (p<0.05). In within-group comparison of the control group, activity of sternocleidomastoid muscle and scalenus anterior muscle showed a significant decrease (p<0.05), and in between-group comparison, there were significant differences in activity of sternocleidomastoid muscle and FVC (p<0.05). Conclusion: Long-term forward head posture restrains exercise performance of the neck and leads to exercise avoidance of the neck during daily activities, thus restraint factors might be created even while breathing. To cut off this link, a constant effort is required and diversified research on the correlation between neck functions and breathing should be conducted.