Study Design. A cross-sectional observational design study was conducted to determine lumbar repositioning error in 15 subjects who had chronic low back pain with a clinical diagnosis of lumbar segmental instability and 15 asymptomatic participants.
Objective. To determine whether individuals with lumbar segmental instability have a decreased ability to reposition their lumbar spine into a neutral spinal position.
Summary of Background Data. Proprioception of the lumbar spine has been investigated in individuals who have low back pain with variable results. The testing procedure’s lack of sensitivity and the nonhomogeneity of groups may be responsible for the conflicting findings.
Methods. Repositioning accuracy of the lumbar spine was assessed using the 3Space Fastrak to determine error in 15 participants with lumbar segmental instability and 15 asymptomatic subjects. The participants were assisted into a neutral spinal sitting posture and then asked to reproduce this position independently over five trials separated by periods of relaxed full lumbar flexion.
Results. Lumbosacral repositioning error was significantly greater in participants with lumbar segmental instability than in the asymptomatic group (t  = 2.48;P = 0.02. There also was a significant difference between the groups at each individual sensor.
Conclusions. The results of this study indicate that individuals with a clinical diagnosis of lumbar segmental instability demonstrate an inability to reposition the lumbar spine accurately into a neutral spinal posture while seated. This finding provides evidence of a deficiency in lumbar proprioceptive awareness among this population.
From the Curtin University of Technology, School of Physiotherapy, Shenton Park, Western Australia.
Acknowledgment date: March 7, 2002.
First revision date: August 8, 2002.
Acceptance date: October 11, 2002.
Device status/drug statement: The submitted manuscript does not contain information about medical devices or drugs.
Conflict of interest: No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this article.
Address correspondence and reprint requests to Peter B. O’Sullivan, PhD, Curtin University of Technology School of Physiotherapy, Selby Street, Shenton Park, Western Australia 6008.