Journal Article Ahead of print
PubMed: 42839170 DOI: 10.1007/s00586-026-10390-9
A global sagittal deviation index (GSDI-5) incorporating upper cervical alignment: initial construct validation in forward head posture.
Eur Spine J
Authors: Katterine N Ríos-Peralta, Kathleen M Curran, David B MacManus, Lukas Schönnagel, Matthias Pumberger, Hendrik Schmidt, Ali Firouzabadi
Affiliations
- School of Medicine, University College Dublin, Dublin, Ireland. Julius Wolf Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.
- School of Medicine, University College Dublin, Dublin, Ireland.
- UCD Centre for Biomedical Engineering, University College Dublin, Dublin, Ireland.
- School of Mechanical & Materials Engineering, University College Dublin, Dublin, Ireland.
- UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland.
- Julius Wolf Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.
- Center for Musculoskeletal Surgery, Charité - University Medicine Berlin, Berlin, Germany.
- Julius Wolf Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.
Abstract
PURPOSE
Forward head posture (FHP) is commonly assessed using isolated cervical measures, potentially overlooking its relationship with global sagittal alignment. This study introduces the Global Sagittal Deviation Index (GSDI-5), a composite measure integrating multiregional sagittal alignment with explicit inclusion of the upper cervical spine.
METHODS
Standing lateral EOS radiographs from 201 adults referred for evaluation of low back pain were analysed and classified into FHP and non-FHP groups. Standardized sagittal parameters across the cervical, thoracic, lumbar, and global spine were combined into a single score. Initial construct validity was examined through known-groups comparisons and convergent analyses with TPA and PI-LL.
RESULTS
Individuals with FHP demonstrated higher GSDI-5 scores. GSDI-5 showed a large effect size for differentiating FHP from non-FHP (Hedges' g = 0.85), slightly exceeding that of TPA (g = 0.81) and PI-LL (g = 0.32), with increasing severity associated with progressive changes in global alignment measures.
CONCLUSION
By integrating upper cervical alignment into a whole-spine framework, GSDI-5 summarizes cranio-cervical behaviour relevant to FHP and may serve as a complementary exploratory measure for global sagittal deviation in radiographic and postural assessment, alongside existing sagittal alignment metrics.
MeSH
Posture, Spine