Methods: Thirty patients with LSS scheduled for spine surgery participated in this study. Lower limb pain was assessed using the Visual Analog Scale (VAS), and the patients were divided into two groups based on the mean scores (patients with scores above and below the mean were classified as the high-VAS and low-VAS groups, respectively). The kinematics of the spine, pelvis, and hip joints during gait were then measured using a 3D motion analysis system. Student paired t -tests were used to compare the angles of the spine, pelvis, and hip during gait between the two groups. Results: Compared to those in the low-VAS group, the spine was significantly extended and bent toward the more painful lower limb side, and the pelvis was significantly anteriorly tilted among individuals in the high-VAS group. Conclusions Patients with LSS experiencing severe pain in their lower limb tend to keep the spine in a more extended position, bend laterally toward the painful side, and have an anteriorly tilted pelvic posture. The dynamic spinal and pelvic alignment was closely related to the intensity of the lower limb pain.

Methods: Thirty patients with ASD aged ≥50 years who were admitted to our hospital between July 2016 and September 2019 were included in this study. X-ray parameters (i.e., sagittal vertical axis, pelvic tilt, and pelvic incidence minus lumbar lordosis) were evaluated from the full-length standing radiographs of the subjects. Trunk and hip extensor strength was evaluated using a hand-held dynamometer. Dynamic postural changes (i.e., sagittal trunk shift during standing, sagittal trunk shift during gait, and delta sagittal trunk shift) were assessed using a three-dimensional motion analysis system. The relationships between dynamic postural change and various X-ray parameters, as well as trunk and hip extensor strength, were examined using multivariable analysis. Results: Multivariable analysis showed that hip extensor strength is the factor most strongly associated with dynamic postural change among the X-ray parameters and physical functions assessed in this study (β=−0.41, R2=0.12). Conclusions We demonstrated the association between dynamic postural change and hip extensor strength in patients with ASD. Our results may be useful to healthcare providers treating patients with ASD. Interventions for dynamic postural change in patients with ASD should focus on hip extensor strength.