The influence of body posture on cervical alignment measured in the sagittal plane on conventional radiographs: a systematic review

Esther van Santbrink; Valérie Schuermans; Ank van de Goor; Rob de Bie; Toon Boselie; Henk van Santbrink; Anouk Smeets

doi:10.1016/j.spinee.2025.01.037

The influence of body posture on cervical alignment measured in the sagittal plane on conventional radiographs: a systematic review

Spine J. 2025 Jan 29:S1529-9430(25)00074-9. doi: 10.1016/j.spinee.2025.01.037. Online ahead of print.

Authors

Esther van Santbrink¹, Valérie Schuermans², Ank van de Goor³, Rob de Bie⁴, Toon Boselie⁵, Henk van Santbrink², Anouk Smeets⁵

Affiliations

¹ Dept. Of Neurosurgery, Maastricht University Medical Centre, Maastricht, The Netherlands; Dept. Of Neurosurgery, Zuyderland Medical Centre, Heerlen, The Netherlands; CAPHRI Institute for Public Health and Primary Care, Maastricht University, Maastricht, The Netherlands. Electronic address: esther.van.santbrink@mumc.nl.
² Dept. Of Neurosurgery, Maastricht University Medical Centre, Maastricht, The Netherlands; Dept. Of Neurosurgery, Zuyderland Medical Centre, Heerlen, The Netherlands; CAPHRI Institute for Public Health and Primary Care, Maastricht University, Maastricht, The Netherlands.
³ Faculty of Psychology and Neurosciences, Maastricht University, Maastricht, The Netherlands.
⁴ CAPHRI Institute for Public Health and Primary Care, Maastricht University, Maastricht, The Netherlands; Department of Epidemiology, Maastricht University, Maastricht, The Netherlands.
⁵ Dept. Of Neurosurgery, Maastricht University Medical Centre, Maastricht, The Netherlands; Dept. Of Neurosurgery, Zuyderland Medical Centre, Heerlen, The Netherlands.

PMID: 39890026
DOI: 10.1016/j.spinee.2025.01.037

Abstract

Background context: Cervical sagittal balance parameters are an important aid in surgical decision-making and influence outcome in cervical spine surgery. In current literature, the normative values of these parameters vary highly within and between patients. This variability might be attributed to body posture.

Purpose: The primary aim is to review the literature on the influence of body posture, including studies that compare sitting or standing positions possibly varying in arm positions, on cervical alignment measured in the sagittal plane on X-rays.

Study design: A systematic review was performed.

Methods: PubMed, Embase, Cochrane Library, Web of Science, and CINAHL were systematically searched for articles published up to and including May 2024. The primary outcome was variability in cervical alignment in the sagittal plane as measured in altering body postures on X-rays. Quality of the included articles was assessed with the QUADAS-2 tool.

Results: Out of 17,628 screened articles, 8 were eligible for inclusion. Articles were excluded based on irrelevant outcomes (n=10,372), duplicates (n=4,315), wrong study design (n=1,462), or the influence of body posture was not described (n=612). Overall cervical alignment ranged from 33.3 degrees lordosis to 3.5 degrees kyphosis. In all studies, statistically significant differences in T1 Slope (T1S), C2C7 Sagittal Vertical Axis (SVA), McGregor Slope (McGS), or C7 SVA were observed with respect to body posture. The observed differences between postures for cervical alignment ranged from 1 to 16.6 degrees.

Conclusions: Body posture significantly influences cervical alignment values measured in the sagittal plane on X-rays. Studies investigating this influence are scarce and vary highly in investigated body postures. Standardization of body posture is imperative to enable optimal comparison of cervical sagittal balance parameters within and between patients, but also between studies. Moreover, the high variability observed raises questions about the comparability of measured values in previously published studies.

Keywords: Body posture; C2-C7 Cobb angle; Cervical alignment; Cervical sagittal balance parameters; Cervical spine; Conventional radiograph; Position; X-ray.

Publication types

Review