Differences in static balance and weight distribution between normal subjects and subjects with chronic unilateral low back pain.

Balance reactions are not routinely evaluated in patients with low back pain. The purpose of this study was to determine if there were differences in static balance and weight distribution between subjects with unilateral low back pain (N = 15) and pain-free controls (N = 15). Measurements included limits of stability (%LOS), target sway, weight distribution on each lower extremity in quiet standing, and center of gravity with measurements of maximal excursion in anterior/posterior and medial/lateral directions. Independent t tests were used to compare data between groups. Compared with control subjects, subjects with low back pain demonstrated greater anterior-posterior center of gravity excursion and total center of gravity excursion with eyes open and greater anterior-posterior, medial-lateral, and total center of gravity excursion, target sway, and %LOS with eyes closed. There was no difference in the weight-bearing distribution between groups. This study suggests that static balance in patients with chronic low back pain may be impaired and should be thoroughly evaluated and integrated into physical therapy treatment programs.