Lifting capacity is associated with central sensitization and non-organic signs in patients with chronic back pain

Abstract

Purpose: To analyze the associations between lifting capacity, and central sensitization (CS) and nonorganic signs (NOS) in patients with chronic back pain (CBP) attending vocational rehabilitation. Materials and methods: Cross-sectional observational multicenter study among patients with CBP undergoing a return to work assessment within care as usual. Main analyses: step 1: partial correlation between lifting capacity, and CS, NOS, and additional variables; step 2: multiple regression in stepwise forward method for dependent variable lifting capacity, and for independent variables CS and NOS, and additional variables significant (p < 0.05) at step 1. All analyses were controlled for sex. Results: Fifty-six patients of mean age 42.5 years and 59% women participated in the study. Correlations between lifting capacity and CS and NOS were r ¼ -0.53 and r ¼ -0.50, respectively. CS and NOS, as well as age and sex, contributed significantly to the final regression model, which explained 57.6% of variance. Conclusions: After controlling for confounders, CS and NOS were negatively associated with lifting capacity in patients with CBP. Explained variance was substantially higher than previously reported studies. ä IMPLICATIONS FOR REHABILITATION The identification of central sensitization and non-organic signs (NOS) in patients with chronic back pain can alert clinicians about central nervous system being in a hypersensitive state and about pain behavior. Central sensitization and NOS are relevant determinants of lifting capacity. Better understanding of the factors affecting lifting capacity lead to better design and tailoring of interventions, resulting in optimized vocational rehabilitation programs and faster return to work. ARTICLE HISTORY

Central sensitization and functioning in patients with chronic low back pain: A cross-sectional and longitudinal study

“…There is some evidence of the association between CS and limited functioning [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], however, these studies utilized limited and diverse CS indicators and functioning measures. Specifically, more self-reported CS-related symptoms [ 12 , 13 , 18 , 20 ], decreased parasympathetic/vagal activity [ 14 , 15 ] , or altered somatosensory responses [ 16 , 17 , 19 ], were associated with higher self-reported pain-related disability and/or lower physical function.…”

“…There is some evidence of the association between CS and limited functioning [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], however, these studies utilized limited and diverse CS indicators and functioning measures. Specifically, more self-reported CS-related symptoms [ 12 , 13 , 18 , 20 ], decreased parasympathetic/vagal activity [ 14 , 15 ] , or altered somatosensory responses [ 16 , 17 , 19 ], were associated with higher self-reported pain-related disability and/or lower physical function. But the indicators of CS varied in the associations; also if somatosensory responses were assessed the associations varied per body site of testing, stimuli and type of tests performed; and functioning was mostly measured with self-reported measures.…”

Detection of Changes on Parameters Related to Heart Rate Variability after Applying Current Interferential Therapy in Subjects with Non-Specific Low Back Pain

“…In this sense, there are NOS that have been related to back pain, such as aerobic functional capacity or somatosensory and/or autonomic function. Among the latter, heart rate variability (HRV) has been considered as a noninvasive, feasible diagnostic tool that evaluates different symptoms and clinical reference signs indicative of persistent pain [ 7 , 8 , 9 ].…”

“…Specifically, detection of changes in HRV have been considered an important diagnostic measure of neurogenic homeostatic regulatory capacity in subjects with low back pain [ 10 ]. Similarly, this measure of autonomic control/balance has been previously proposed as a measure of return-to-work decision making in subjects with musculoskeletal disorders [ 7 ].…”

“…Evidence-based guidelines about the management of chronic low back pain highlight the importance of recognizing that chronic pain can alter the autonomic balance, with increased sympathetic activity reflected in altered HRV [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. These findings show a solid influence of the sympathetic and parasympathetic nervous systems in pain regulation.…”