Sagittal balance dynamics during gait in patients with degenerative spine disease

STUDY DESIGN: Observational Case-Control Study. PURPOSE: To evaluate the dynamics of sagittal balance during gait in patients with degenerative spine disease compared with matched controls. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.