Relationship of sagittal thoracic postural and inlet parameters with nontraumatic neck pain: a systematic review and meta-analysis

Abstract

Abstract Objectives Neck pain (NP) is associated with substantial disability as well as economic and psychological distress. T1 slope (T1S) and thoracic inlet angle (TIA) reflect cervical sagittal imbalance, which can have clinical/surgical implications. Evidence of the relationship between the sagittal thoracic posture and inlet parameters and pain and functional status is inconclusive. This review aimed to determine whether these parameters differ between NP and pain-free subjects and to critically appraise their correlation with NP measures. Methods The review consists of 15 studies that evaluated thoracic postural and/or inlet parameters on adult NP patients, after a comprehensive literature search from EBSCO, PubMed, Scopus, Embase, and Web of Science databases. Statistical heterogeneity, mean pooled difference (MPD), and effect size were calculated to establish a relationship among studies and to assess the correlation of thoracic postural and inlet parameters with NP measures, positional variation, and NP predictors. Sensitivity analysis was performed in case of high between-studies heterogeneity. The risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. Certainty of evidence was graded using GRADE approach. Results Only TIA had a significant MPD of 2.12 (0.48, 3.75). The other measures, namely T1S, neck tilt (NT), high thoracic angle, and thoracic kyphosis angle, were not different between NP and asymptomatic subjects. NP population had a 3.14° higher TIA, 4.12° higher NT, and 2.26° lower T1S in lying position (relative to upright). Only thoracic kyphosis and T1S predicted the presence of NP. Very low to low certainty of evidence exists for most of the outcome measures assessed. Conclusion Limited evidence is available for the association between the sagittal thoracic postural and inlet parameters in nontraumatic cervical dysfunction. Test-position differences reflect marginally lower T1S, and higher TIA, NT in lying than the upright. The existing evidence is insufficient to prove a minor, if any, association of thoracic posture with NP.