INTRODUCTION: Lumbar degenerative kyphosis has dynamic changes which are closely associated with the motion of pelvis. We verify the availability of radiography and gait analysis in order to analyze the changes of pelvic tilt before and after gait in patients with LDK.
METHODS: We analyzed 18 lumbar degenerative kyphosis patients who didn't have multiple vertebral compression fractures, past history of spinal surgery or surgery for degenerative arthritis of knee or hip, and obesity which makes a marker error in gait analysis. Pelvic tilt was evaluated statically utilizing radiographs and dynamically utilizing gait analysis. Linear parameters of gait cycle and kinematic datas were obtained in gait analysis.
RESULTS: The mean walking velocity was 80.7cm/s, and it decreased largely to 65%, compared with normal value. The cause of decreased walking velocity was decrease of stride length, not decrease of cadence. The mean static pelvic tilt in gait analysis was –1.3 ± 8.0°, and there were 8 cases of anterior tilt and 10 cases of posterior tilt. The mean pelvic tilt during gait was 12.5 ± 8.2°, and there were 17 cases of anterior tilt and 1 case of posterior tilt. It was statistically significant difference (p
DISCUSSION: Though there was no statistical significance, we observed anterior pelvic rotation after gait on radiographs. As fatigue of pelvic extensor muscles increases during gait, anterior pelvis tilt increases with statistical significance in gait analysis. Therefore gait analysis is thought to be useful for evaluate the dynamic change of pelvic tilt in patients with LDK.