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 judgement tasks, a method of testing the integrity of cortical maps.
Methods: One thousand and eight volunteers completed an online left/right trunk judgement 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 healthy 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.
(C) 2014 by Lippincott Williams & Wilkins