medwireNews: Patients with low back pain who also have pain in their chest, abdomen or groin experience greater levels of pain and disability, shows research that suggests a need for specific management of such patients.
Although unable to determine the underlying mechanisms, the researchers speculate that visceral referred pain may explain the association.
“[N]eural convergence of visceral afferent fibres with somatic afferent fibres in the spinal cord can cause pain perceived to arise from somatic structures,” lead researcher John Panagopoulos (Macquarie University, Sydney, New South Wales, Australia) and colleagues explain.
This visceral referred pain is then likely to contribute to the pain caused by low back pain, they add.
A total of 2974 patients with back pain participated in the study, 583 of whom had anterior trunk pain, in either the chest, abdomen or groin.
These patients experienced significantly worse pain than those without trunk pain, with an average score across three 11-point pain rating scales of 6.0 versus 5.5, where 0 signifies no pain and 10 or above the worst pain imaginable.
Disability was also significantly worse for those with trunk pain, with average baseline Roland-Morris Disability Questionnaire scores of 66.4 versus 60.2 out of a possible 100.
The differences in pain and disability remained significant at the 3- and 12-month assessments and trunk pain was still significantly associated with disability after confounding factors, including widespread body pain, had been accounted for.
The association between trunk pain and low back pain disappeared on multivariate analysis, but in a post hoc analysis adjusting only for widespread pain the effect of anterior trunk pain remained significant, indicating some independent impact.
The researchers acknowledge, however, that the effect of trunk pain on low back pain may differ for each of the specific areas and separate analyses are warranted.
The presence of trunk pain did not affect the rate of recovery of low back pain or disability, explaining less than 1% of variance in outcome.
Although their study was not designed to provide evidence of treatment need, the researchers suggest in Pain that “patients with low back pain and anterior trunk pain represent a clinical subgroup requiring specific management.”
They add that distinguishing between visceral pain and musculoskeletal pain in the anterior trunk could be of potential clinical importance.
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2014
By Lucy Piper, Senior medwireNews Reporter