Postural control and trunk stability on sway parameters in adults with and without chronic low back pain

Background Postural sway changes often reflect functional impairments in adults with chronic low back pain (LBP). However, there is a gap in understanding how these individuals adapt their postural strategies to maintain stability. Purpose This study investigated postural sway distance and velocity, utilizing the center of pressure (COP) and center of gravity (COG), between adults with and without LBP during repeated unilateral standing trials. Methods Twenty-six subjects with LBP and 39 control subjects participated in the study. Postural sway ranges, COP/COG sways, and sway velocities (computed by dividing path length by time in anteroposterior (AP) and mediolateral (ML) directions over 10 s) were analyzed across three unilateral standing trials. Results A significant group interaction in sway range difference was observed following repeated trials (F=5.90, p=0.02). For COG sway range, significant group interactions were demonstrated in both directions (F=4.28, p=0.04) and repeated trials (F=5.79, p=0.02). The LBP group demonstrated reduced ML sway velocities in the first (5.212.43 for the control group, 4.16 +/- 2.33 for the LBP group; t=1.72, p=0.04) and second (4.87 +/- 2.62 for the control group, 3.79 +/- 2.22 for the LBP group; t=1.73, p=0.04) trials. Conclusion The LBP group demonstrated decreased ML sway velocities to enhance trunk stability in the initial two trials. The COG results emphasized the potential use of trunk strategies in augmenting postural stability and optimizing neuromuscular control during unilateral standing.