Deep Neck Flexor and Sternocleidomastoid Muscle Thickness Change in Persons with No Current Neck Pain using Rehabilitative Ultrasonograpic Imaging

Abstract

Purpose: The purpose of the study was to investigate the thickness of deep neck flexors (DNF) and sternocleidomastoid muscle (SCM) bilaterally during deep neck flexor endurance test using ultrasonography images. Methods: Healthy volunteers (n= 22), 20-25 (mean 22.2) years old, were recruited for the study. Participants were asked to perform the craniocervical flexion test (CCFT) in a seated position to measure deep neck flexor endurance. The thickness of DNF and SCM was assessed bilaterally and was measured using ultrasonography images at resting, contracted, pre-terminal and terminal phases of the neck muscle endurance test. Muscle contraction pattern was also observed along with the changes in muscle thickness from the resting phase to the terminal phase. Repeated-measure ANOVA was employed to compare muscle thickness bilaterally at each phase. Results: The thickness of right and left muscles was found to be significantly different in DNF both at resting and contracted phases (p = 0.02, p < 0.01, respectively), whereas no significant difference was observed in SCM at resting or contracted phases (p = 0.59, p = 0.18, respectively). Thickness changes from resting to contracted phase were not significantly different both in DNF and SCM (p= 0.18, p= 0.22, respectively). Muscle contraction patterns in right and left muscles were shown to be similar. Conclusion:The current study, performed on (with) healthy subjects, significantly detected different right and left muscle thickness in DNF, but the muscle contraction patterns were similar in DNF and SCM bilaterally. Further study is required to investigate DNF and SCM muscle size and function in people with neck pain.

Performance of Longus Colli Muscle in Women with and without Forward Head Posture

“…Previous studies conducted on patients with neck pain reported smaller cross-sectional area (CSA) of LCo (22), altered motor control strategy including reduced activity of DNF muscles and increased activity of superficial neck flexor muscles (SCM) during CC flexion (23). Increased activity of superficial neck flexor muscles may be a compensatory mechanism for reduced activity of DNF muscles (24). In this study we used 50% of maximum isometric contraction of CC flexion because, according to the results of previous studies there was not significant changes in muscle thickness in contraction levels above 50% of maximum isometric contractions (17).…”

“…Muscle thickness change during CC flexion has been neglected in previous studies. This parameter is important because muscle thickness change can be informative about muscle contraction pattern (24) and more muscle thickness changes express more muscle activity (11). Measurement of muscle thickness change of cervical muscles can indicate stabilizing role of these muscle, because deep neck muscles are more active in contraction state relative to resting state to provide stability of the cervical spine (19).…”

“…This significant difference highlighted impairment of performance of LCo in FHP. FHP alter length and length-tension relationship of the neck muscles and can lead to decreased force production ability and weakness of LCo muscle (18,24). Previous studies indicated that FHP is associated with weakness of DNF muscles in patients with cervicogenic headache (8).…”