The effect of feedback respiratory exercise on muscle activity, craniovertebral angle, and neck disability index of the neck flexors of patients with forward head posture

[Purpose] This study aimed to simultaneously investigate the activities of the sternocleidomastoid muscle and scalenus anterior muscle, which are agonists of neck and breathing accessory muscles, by implementing breathing exercises. [Subjects and Methods] Thirteen subjects were selected for the experimental group, which performed feedback respiratory exercises with McKenzie exercises, and 12 subjects were selected for the control group, which performed McKenzie exercises alone. The intervention program was performed for 30 minutes a session, once a day, four times a week, and for 2 weeks before conducting the experiment. Before intervention, muscle activity was measured using surface electromyogram, and the neck disability index was evaluated. [Results] There were meaningful differences in activities of the sternocleidomastoid muscle and the scalenus anterior muscle, craniovertebral angle, and neck disability index within both the experimental group and control group after intervention. There also were meaningful differences in sternocleidomastoid muscle and neck disability index changes between groups. [Conclusion] Neck flexors as accessory respiratory muscle can affect inefficient respiratory imbalance of forward head posture patients. Multimodal intervention method should be studied continually and not be exposed to upper chest breathing patterns by preventing such phenomenon.