Motor imagery in people with a history of back pain, current back pain, both, or neither.

INTRODUCTION

There is mounting evidence that cortical maps are disrupted in chronic limb pain and that these disruptions may contribute to the problem and be a viable target for treatment. Little is known as to whether this is also the case for the most common and costly chronic pain-back pain.

OBJECTIVES

To investigate the effects of back pain characteristics on the performance of left/right trunk judgment tasks, a method of testing the integrity of cortical maps.

METHODS

A total of 1008 volunteers completed an online left/right trunk judgment task in which they judged whether a model was rotated or laterally flexed to the left or right in a series of images.

RESULTS

Participants who had back pain at the time of testing were less accurate than pain-free controls (P=0.027), as were participants who were pain free but had a history of back pain (P<0.01). However, these results were driven by an interaction such that those with current back pain and a history of back pain were less accurate (mean [95% CI]=76% [74%-78%]) than all other groups (>84% [83%-85%]).

DISCUSSION: Trunk motor imagery performance is reduced in people with a history of back pain when they are in a current episode. This is consistent with disruption of cortical proprioceptive representation of the trunk in this group. On the basis of this result, we propose a conceptual model speculating a role of this measure in understanding the development of chronic back pain, a model that can be tested in future studies.