Regional lumbar motion and patient-rated outcomes: A secondary analysis of data from a randomized clinical trial

Objective: The purpose of this study was to examine the relationship in change scores between regional lumbar motion and patient-rated pain of the previous week and back-related function in chronic low back pain patients enrolled in a randomized clinical trial and treated with either exercise therapy or spinal manipulation using 6 different motion parameters. Methods: Regional lumbar motions were sampled using a 6 degrees of freedom instrumented spatial linkage system in 199 participants at baseline and 12-week follow-up. The regional lumbar motion data were analyzed as a total cohort as well as relative to subgroup stratifications; back pain only vs back and leg pain, and treatment modality. For identifying clinically meaningful improvements in the measurements of back pain and back-related function, we used a 30% threshold. Results: The relationship between change scores in patient-rated outcomes and objective measures of regional lumbar motion was found to be weak. In contrast, distribution of pain and treatment received affected associations between motion parameters and patient-rated outcomes. Thus, stronger correlation coefficients and significant differences between clinically relevant improved vs no clinical relevant change were found in some motion parameters in the subgroup with back pain only and the treatment group receiving spinal manipulation. Conclusion: Overall, changes in regional lumbar motion were poorly associated with patient-rated outcomes measured by back-related function and back pain intensity scores. However, associations between regional lumbar motion vs patient-rated pain and back-related function were different in relative subgroups (back pain only vs back and leg pain and treatment).