Comparative analysis of ground reaction forces and spatiotemporal gait parameters in older adults with sway-back posture and chronic low back pain: a cross-sectional study.

Background: Gait alterations associated with postural deviations are a significant factor contributing to functional limitations in older adults. Among these, sway-back posture has been linked to chronic low back pain (CLBP), defined as pain persisting for more than three months. This study aimed to analyze ground reaction forces (GRFs), loading and unloading rates, spatiotemporal gait parameters, and the asymmetry index (ASI) in older adults with sway-back posture and CLBP (SBCLBP) without adjusting for walking speed.

Methods: A total of 36 older adults were included and categorized into three groups: 12 with SBCLBP, 12 with CLBP without sway-back posture, and 12 without CLBP. GRFs and spatiotemporal gait parameters-including stride time, cadence, stride length, gait speed, and stance phase duration-were recorded for all participants. GRFs were analyzed at the anteroposterior peaks during heel contact (Fx1) and push-off (Fx2) phases, as well as at the vertical force peaks at heel contact (Fy1), mid-stance (Fy2), and push-off (Fy3) phases. Additionally, mediolateral force peaks (Fz) during heel contact were assessed. The ASI was calculated for all participants. Between-group differences were examined using one-way ANOVA and ANCOVA.

Results: Cadence, stride length, gait speed, and Fy2 values were significantly lower in the SBCLBP and CLBP groups compared to the control group. Additionally, these parameters were significantly lower in the SBCLBP group than in the CLBP group. However, the loading rate demonstrated greater variability across participants. No significant differences in ASI were observed among the groups.

Conclusions: Older adults with SBCLBP exhibit distinct gait characteristics compared to those with CLBP alone and those without CLBP. These differences may be attributed to structural postural alterations, distinguishing this subgroup from individuals with isolated CLBP. These findings underscore the need for targeted rehabilitation strategies tailored to the specific biomechanical alterations observed in this population. Future research should focus on optimizing intervention protocols to enhance stability and mitigate pain-related gait impairments associated with aging.

Trial registration: Current Controlled Trials using the UMIN Clinical Trials Registry website with ID number of, UMIN000055653 "Retrospectively registered" at 27/09/2024.