Abstract
[Purpose] This study examined the relationship between craniovertebral (CV) angle and the activity of the sternocleidomastoid (SCM) during performance of the cranio-cervical flexion test (CCFT) by healthy subjects. [Subjects] Ten volunteer subjects without neck pain enrolled in this study. [Methods] SCM electromyographic (EMG) activity was recorded at five incremental levels of CCFT. Side-view pictures of each subject were taken in the sitting position to assess forward head posture by measurement of the CV angle. [Results] The CV angle was negatively correlated with activity of the SCM muscles at 30 mmHg increments of CCFT (r= -0.75). [Conclusion] Greater activity of SCM was present during the highest stage of the CCFT in subjects with small CV angle. This suggests a small CV angle influences the activity of superficial neck flexors muscles.
