Sagittal balance dynamics during gait in patients with degenerative spine disease

Observational Case-Control Study.

To evaluate the dynamics of sagittal balance during gait in patients with degenerative spine disease compared with matched controls.

33 patients with pathological sagittal balance parameters on standing radiographs and 31 matched controls underwent three-dimensional motion capture analysis during a six-minute walking assessment. Data were collected across five phases: pre-walk, initial-walk, mid-walk, end-walk, and post-walk. Spino-pelvic (pelvic angle, lumbar lordosis, thoracic kyphosis) and sagittal balance parameters (sagittal trunk shift and angle, global tilt), as well as lower limb joint angles were assessed.

The greatest decrease in sagittal balance occurred during the transition from standing to walking, with significantly larger changes observed in the study group (C7-L5-sagittal trunk shift increasing from 69.1 ± 50.6 mm to 138.7 ± 51.9 mm) compared to controls (increase from 20.9 ± 18.8 mm to 69.2 ± 19.7 mm; p = 0.020). The decrease was primarily due to increased thoracic kyphosis and, in some cases, reduced pelvic retroversion. During continued walking, sagittal balance remained stable at the group level, with only a subgroup in both groups demonstrating a notable decrease. No significant differences in changes during walking were found between groups. After walking, parameters largely returned close to baseline in a standing position, indicating an almost complete recovery of sagittal balance.

Compensatory mechanisms for maintaining sagittal balance are significantly more effective in a standing position than during walking. While sagittal balance remains stable in most patients during short-term walking, a notable decrease occurred in several individuals. Therefore, further research is needed to identify prognostic factors associated with a decrease in sagittal balance during walking.