(313) Association between Measures of Function and Pain Perception in Older Adults with Chronic Low Back Pain

Abstract

This investigation examined the association between measures of function and pain perception in older individuals with chronic low back pain (CLPB). Data from eight subjects older than 65 were analyzed. Measures of function included the 2-minute walk test (2-MWT) and the Oswestry Disability Index (ODI). Pain perception was examined by pressure pain threshold (PPT). Clinical pain was obtained with the visual analogue scale (VAS). PPT was assessed bilaterally at T12, L5, and S2. Values obtained during PPT were averaged together to quantify local PPT. Descriptive statistics were collected and Pearson correlation moment was performed to identify correlations. A stepwise regression model was used to identify the stronger predictor of PPT, (PPT was used as the dependent variable and ODI and 2-MWT were entered as the independent variables). Results showed that local PPT was significantly correlated with both objective and subjective measures of function (2-MWT r2=0.800, p=0.017, ODI r2=-0.866, p=0.005). Correlation analysis showed that clinical pain measured with the VAS scale was not associated with measures of disability used in this study (p>0.05). Stepwise regression model revealed that ODI alone was responsible for 70% of the variability in PPT (r2=0.708, β=-0.866, p=0.005). 2-MWT explained an additional 22% of the variability in PPT (r2=0.923, β=0.502 p=0.008). Results from this modest sample of participants with CLBP suggest that perception of disability and level of activity as evaluated by the 2-MWT have a strong influence in experimental pain perception. Surprisingly, clinical pain was not associated with measures of disability which indicates that the use of the VAS alone may not be enough to assess pain in older individuals with CLBP. Moreover, the 2-MWT could be a simple and easy way to assess changes in physical activity in older individuals.