Analysis of cervical and upper thoracic spinal segmental rotation angles during end-range neck rotation: Comparison with and without neck pain

Background: Neck pain is a common manifestation of musculoskeletal disorders of the cervical and thoracic spine. Manual therapy interventions to the thoracic spine are recommended for treating patients with several types of neck pain. However, only a few studies have investigated the thoracic spine mobility associated with neck movement. Objectives: Compare cervical and upper thoracic rotation angles in subjects with and without neck pain. Methods: The subjects included nine individuals who experienced neck pain (pain, Group P) and 11 who did not (non-pain, Group N). The rotation angle was measured using MRI. The imaging limb position was at 90% of the maximum neck rotation. The MR images were analyzed using image analysis software to calculate the rotation angle of C1 to Th3. The rotation angle of the segment was then calculated by subtracting the rotation angle corresponding to the lower vertebra from that corresponding to the upper vertebra. The total rotation of each segment was calculated as the sum of the right and left rotation angle. Then, the segmental rotation angles were compared between groups. Results/findings: The rotation angles of C3-C4, C7-Th1, and Th1-Th2 were significantly smaller in Group P than in Group N, and C5-C6 and C6-C7 were significantly larger in Group P than in Group N. There was no statistical difference in rotational angle at all other spinal levels measured. Conclusions: The results of this study indicate subjects with neck pain had hypermobility of the lower cervical spine and hypomobility of the cervico-thoracic junction and upper thoracic spine compared with subjects without neck pain. These results add to current understanding of biomechanical factors that may be related to neck pain.