Spino-pelvic- lower extremity balance during walking in elderly patients with spinal kyphosis.

BACK GROUND: Patients with spinal kyphosis were radiographically evaluated while standing. However, the spino-pelvic alignment during walking is different. This study examined the spino-pelvic-lower extremity alignment during walking by a three-dimensional (3D) motion analysis.

METHODS: Twenty-six patients with a sagittal vertical axis of ≥4 cm (male: female, 5:21; average age, 66 years) were evaluated. Using a 3D motion capture system, the trunk and pelvic anterior inclination angles, hip and knee joint angles were measured during a 3-min walk. The correlation coefficient between the change of the trunk anterior inclination angle and each parameter at the beginning of walking was calculated, and those parameters were compared with radiographic measurements.

RESULTS: The patients were divided into two groups according to the change of the trunk anterior inclination angle: the large change group included 14 patients with an increase of ≥5° between the beginning and end of the 3-min walk; the small change group included 12 patients with an increase of <5°. The pelvic anterior inclination angle showed a significant difference between the two groups at the first gait cycles. The pelvic anterior inclination angle and the hip joint angle in the large change group showed a significant difference between the first and last cycles. The correlation coefficient revealed a significant association between the change in the trunk anterior inclination angle and the pelvic anterior inclination angle at the beginning of walking. There were no significant differences between the two groups in any radiographic spino-pelvic parameters.

CONCLUSIONS: There were two types of patients with spinal kyphosis: patients with a small pelvic anterior inclination angle at the beginning of walking showed slight progression in their trunk anterior inclination, whereas those with a large pelvic angle showed a large degree of progression in their pelvic and trunk inclination during walking.