The effects of a lumbar support on repositioning error in subjects with low back pain

Objective: To determine whether a lumbar support improves trunk repositioning error (RE), an aspect of proprioception. Design: RE was measured with and without a lumbar support. Setting: Outpatient clinic. Participants: Twenty subjects with chronic low back pain (LBP) and 20 control subjects. Intervention: Subjects wore the lumbar support for 2 hours and then testing was repeated. Main Outcome Measures: Standing with legs and pelvis immobilized, subjects moved to a predetermined target position and then attempted to replicate the position. The 3-dimensional position of the trunk was measured with a 3Space Tracker. RE was calculated as the absolute difference between the actual target position and the subject-perceived target position. Testing was performed with and without a lumbar support both before and after wearing the support for 2 hours. Results: In subjects with LBP, RE was significantly lower with a support in flexion, extension, and right lateral bending. In control subjects, RE was significantly lower when wearing the support in left bending only, and RE was significantly higher in control subjects after wearing the support for 2 hours. Conclusions: A lumbar support improves trunk RE. In subjects with LBP, this result was significant in the sagittal plane and in right lateral bending, whereas in control subjects, it was significant only in left lateral bending.