TY - JOUR T1 - Disrupted working body schema of the trunk in people with back pain JF - British Journal of Sports Medicine JO - Br J Sports Med SP - 168 LP - 173 DO - 10.1136/bjsm.2009.061978 VL - 45 IS - 3 AU - H Bray AU - G L Moseley Y1 - 2011/03/01 UR - http://bjsm.bmj.com/content/45/3/168.abstract N2 - Background To test whether working body schema of the trunk is disrupted in people with back pain using a motor imagery task in which one decides whether a pictured model has their trunk rotated to the left or to the right. The authors hypothesised that chronic back pain is associated with reduced accuracy of left/right trunk rotation judgements. Methods 21 Patients with back pain and 14 controls completed two tasks, each involving two trials of 40 images: a left/right hand judgement task, which was used as a control task, and the left/right trunk rotation judgement task. Two (task) × three (group: bilateral back pain, unilateral back pain and control) analyses of variance were undertaken on mean response time and accuracy. Results Response time was similar across participants and tasks (NS). Accuracy was not. The patients with bilateral back pain made more mistakes on the left/right trunk rotation task than patients with unilateral back pain, who in turn made more mistakes on that task than the controls (body part × group interaction; p<0.001). The mean (95% CI) accuracy for left/right trunk rotation judgements was 53.4% (44.5% to 62.3%) for the patients with bilateral back pain, 67.2% (60.2% to 74.1%) for the patients with unilateral back pain and 87% (75% to 98%) for the control participants. This pattern was not observed on the left/right-hand judgement task, on which all three groups made correct judgements about 83% of the time (NS). Discussion Chronic back pain is associated with disruption of the working body schema of the trunk. This might be an important contributor to motor control abnormalities seen in this population. ER -