Plausible impact of forward head posture on upper cervical spine stability

Abstract

The cervical spine is responsible for allowing mobility and stability to the head and neck. Any deviation to the center of gravity of the head results in an increase in cantilever loads, which can be particularly damaging to the upper cervical joints. Excessive neck bending also exaggerates stretching through the cervical spine and all of the spinal structures below. It has been reported that forward head posture (FHP) can cause a multitude of disorders including cervical radiculopathy, cervicogenic headaches and cervicogenic dizziness. Most of these conditions manifest with clusters of painful symptoms and spine dysfunctions. The purpose of this case study is to describe the radiographic imaging considerations and to illustrate the potential impacts in symptomatic adults with FHP. We randomly selected radiographs of three individuals with FHP who had undergone cervical adjustment for cervical pain. The occipito-axial (C0-C2) and atlanto-axial (C1-C2) joints were assessed via the C0-2 distance from the C2 base to the McGregor line (Redlund-Johnell criterion) and the Ranawat C1-2 index, in addition to subjective radiographic parameters. By comparing the radiographs of before-and-after intervention of each patient, a regressive joint spacing was observed from both indices. Such a long-lasting stretching concordant with FHP was assumed to be hazardous to joint stability. A definite conclusion, however, cannot be drawn due to the small sample size and a lack of convincing measurements.

Keywords: Atlantoaxial joint; cervical adjustment; forward head posture; instability; occipito-axial joint.

Conflict of interest statement

The authors have no conflicts of interest to declare.

Copyright: © 2020 Journal of Family Medicine and Primary Care.

Figures

Figure 1

X-ray comparison of pre- and post-intervention in Case 1. (a) The initial X-ray displayed a loss of cervical lordosis, backward subluxation of the C4 on C5 (red circle), and an occipital enthesophyte (white arrow). The cervical gravity line (blue dotted line) fell forward of the C7 suggestive of anterior head placement. (b) The 9 months follow-up X-ray showed the correction of both the neck curve and the forward head posture. The cervical gravity line fell within the C7 vertebra. Redlund-Johnell criterion (white dotted line) was reduced by 11.11% and Ranawat index (red dotted line) was reduced by 13.72%

Figure 2

Cervical spine lateral view of Case 2. (a) Prior to treatment lateral radiograph displayed a reverse cervical lordosis, degenerative spondylosis with ankylosis of the C7/T1 facet joints (red circle). The cervical gravity line (blue dotted line) just touched the anterior body of the C7. (b) The repeat lateral radiographs 9 months later exhibited improved general cervical lordosis. A smooth vertical alignment of each posterior body corner was noted. The cervical gravity line fell within the C7 vertebra. Redlund-Johnell criterion (white dotted line) was reduced by 6.55% and Ranawat index (red dotted line) was reduced by 8.88%

Figure 3

Open mouth radiographs of Case 2 (a) and of Case 3 (b) at initial presentation. There was symmetrical spacing of lateral zygapophyseal (C1-C2) joints and of odontoid-lateral mass intervals. Note a deviation of the C2 spinous process with respect to the alignment of the dens, a suggestive finding of C2 rotation

Figure 4

Initial and follow-up radiographs of Case 3. (a) Initial radiograph showed a loss of cervical lordosis, osteophytic lipping of the vertebrae, narrowing of the joint space of the C7/T1, and facetitis of the right C5/C6 and C7/T1 facet joints. (b) The repeat radiography 2 years later exhibited improved general cervical lordosis. There was a smooth vertical alignment of each posterior vertebral corner. Redlund-Johnell criterion (white dotted line) was reduced by 6.34% and Ranawat index (red dotted line) was reduced by 10.41% FHP (Forward head posture)