Sagittal alignment patterns in forward head posture: an EOS-based head-to-pelvis correlation analysis

Area of Science:

• Orthopedics
• Biomechanical Engineering
• Radiology

Background:

• Forward head posture (FHP) is prevalent, often linked to prolonged screen time and affecting spinal alignment.
• The craniovertebral angle (CVA) alone is insufficient for assessing comprehensive sagittal spinal balance.
• Understanding head-to-pelvis alignment is crucial for evaluating postural adaptations.

Purpose of the Study:

• To evaluate head-to-pelvis sagittal balance (SB) patterns in individuals with and without FHP.
• To investigate the distribution of sagittal alignment across the spine, focusing on the upper cervical region.
• To compare SB parameters between FHP and non-FHP groups.

Main Methods:

• Retrospective radiographic study involving 201 adults with low back pain (LBP).
• EOS radiographs were used to analyze 16 SB parameters from head to pelvis.
• Participants were stratified into FHP and non-FHP groups based on a CVA threshold.

Main Results:

• Individuals with FHP exhibited increased upper cervical extension, T1 slope, thoracic kyphosis, and global sagittal vertical axis.
• Lumbar lordosis and spinopelvic parameters were comparable between groups.
• In FHP, correlations shifted from subaxial (C2-C7) to upper cervical (C0-C1, C0-C2) and cervico-thoracic parameters.

Conclusions:

• FHP is associated with a redistribution of sagittal alignment relationships towards the upper cervical and cervico-thoracic spine.
• Lumbar structural alignment is preserved in individuals with FHP.
• CVA-based assessments are limited in capturing the full scope of whole-spine postural adaptations in FHP.