Abstract
[Purpose] The purpose of this study was to investigate the influence of cervical spine joint mobilization on sternocleidomastoid muscle activity and thickness and longus colli muscle thickness at the time of craniocervical flexion exercise using surface electromyography and ultrasonography. [Subjects and Methods] The subjects of this study were 42 healthy men (mean age: 26.5 years). They were randomly divided into cervical spine distraction mobilization, cervical spine flexion mobilization, cervical spine distraction and flexion mobilization, and sitting rest groups. [Results] After cervical spine distraction and flexion mobilization, the sternocleidomastoid muscle activity and thickness rate of change decreased significantly, and the longus colli muscle thickness rate of change increased significantly. [Conclusion] These results suggest that cervical spine mobilization in the distraction and flexion directions influences cervical flexor muscle activity and the rate of change of muscle thickness at the time of craniocervical flexion exercise.
