Background: Chronic non-specific neck pain (CINP) is common, but the etiology remains unclear. This study aimed to examine the relationship between cervical muscle composition (cervical multifidus and longus capitis/longus colli), morphometry, range of movement, muscle function, and disability severity (Neck Disability Index) in patients with CINP. Methods: From September 2020 to July 2021, subjects underwent cervical MRI and clinical tests (cervical range of motion, cranio-cervical flexion test, neck flexor, and extensor muscle endurance). MRI analysis comprised muscle cross-sectional area, volume, and fat infiltration of multifidus and longus colli between C4 and C7 levels. Results: Twenty-five participants were included. Multiple linear regression analysis indicated that NDI was positively correlated with the volume percentage of fat infiltration of the multifidus (B = 0.496), negatively correlated with fat-free muscle volume of the multifidus normalized by subject height (B = −0.230), and accounted for 32% of the variance. There was no relationship between neck disability and longus capitis/longus colli morphology. We also found no relationship between neck disability scores, neck flexor or extensor muscle endurance, or the outcome motor control test of craniocervical flexion (p > 0.05). Conclusions: Neck disability was moderately correlated with the percentage of fat volume in the multifidus muscle and fat-free volume of the multifidus. There was no relationship between NDI scores and muscle function test outcomes or any fat or volume measures pertaining to the longus colli muscle.
Objective To investigate the frequency and clinical aspects of patients with neck pain who responded and did not respond to scapular repositioning and to determine the clinical features associated with a positive response. Design Cross-sectional study. Setting Research unit, Department of Physical Therapy, Chiang Mai University. Participants Volunteers with non-specific neck pain aged 18–59 years were recruited between May 2020 and February 2021 from hospitals, clinics, university and community. Outcome measures Clinical data documented were neck pain (intensity, duration and disability), the presence of headache, type of scapular dysfunction, cervical musculoskeletal impairment (range of motion (ROM), flexion rotation test (FRT) and location of any symptomatic cervical joint dysfunction), upper limb functional limitation and self-reported disability. Manual scapular repositioning was performed on the side of neck pain. Participants were categorised as responsive or non-responsive based on a change in pain and/or cervical rotation range. Results A total of 219 people with neck pain responded to advertisements, of which 144 were eligible. Of the eligible participants, 107 (74.3%) demonstrated a clinically relevant improvement in either neck pain or rotation range or both following the scapular repositioning and 37 (25.7%) had no relevant improvement. The responsive group had a high incidence of scapular downward rotation, greater neck pain intensity, headache and cervical musculoskeletal impairment (reduced ROM, positive FRT and symptomatic C1-3 dysfunction) compared with the non-responsive group (p<0.05). A logistic regression model revealed that features strongly associated with a positive response were the presence of headache (Exp(B)=6.0, 95% CI 2.3 to 15.8), scapular downward rotation (Exp(B)=5.3, 95% CI 2.3 to 12.6) and a positive FRT (Exp(B)=4.0, 95% CI 1.5 to 10.6). Conclusion Almost 75% of neck pain patients with altered scapular alignment responded to scapular repositioning. The predominance of upper cervical dysfunction with a downwardly rotated scapular in this group suggests a role of poor axioscapular muscle function which might benefit from rehabilitation.