The effect of physical activity on beliefs associated with adherence and pain-related disability in people with chronic low back pain

Abstract

Background. Exercise is the first step recommendation for chronic low back pain (CLBP). However, the best approach for practitioners prescribing exercise to CLBP patients is unclear, and the efficacy of exercise in reducing pain-related disability is debated. Moreover, it is unknown if any particular mode of exercise or accompanying belief about physical activity holds any effect on manipulating CLBP patient beliefs associated with adherence or pain-related disability. Aim. The aim of this thesis was to investigate how CLBP patient beliefs associated with adherence and pain-related disability are manipulated through physical activity. Therefore, this thesis aimed to observe: 1) if there are any differences between individualised and general exercise prescriptions at manipulating adherence and patient beliefs associated with adherence, 2) the influence of psychosocial variables associated with pain-related disability in a generalizable sample of people with CLBP, 3) if the belief physical activity is for CLBP manipulates psychosocial variables associated with pain-related disability, and 4) to provide preliminary results and methodological consideration to a larger longitudinal observational study. Methods. One randomized controlled trial (RCT) and one cross-sectional observational study were undertaken to address the aims of this thesis. The RCT addressed the first aim of this thesis. The RCT examined the effects of an 8-week individualised and general exercise program on clinical outcome measures, adherence, and beliefs associated with adherence. Data were collected at baseline, after the initial consultation, and at the conclusion of the exercise program. Data collection after the initial session allowed for observation of patient beliefs after the different structure and consequently information provided in the initial consultation of an individualised program, compared to a general exercise prescription. Data collection at 8-weeks allowed observation of clinical outcomes, adherence to each intervention, and if information the program was individualised compared to a general prescription for back pain changed patient beliefs. The cross-sectional observational study was designed to examine beliefs associated with pain-related disability in a generalizable sample of people with CLBP, as compared to only using participants who are already engaging with exercise interventions. This study was designed to address the second, third, and fourth aim of the thesis. Self-report measures were collected to observe if psychosocial variables associated with CLBP explain the relationship between pain and disability. Furthermore, participants were asked if they were engaging in physical activity, and if they were doing physical activity for their CLBP. Due to not providing an intervention or standardising the physical activity participants were engaging with, this allowed observation of the belief exercise was for CLBP. This design allowed comparison of clinical and psychosocial measures between participants who did and did not report engaging with physical activity for CLBP. These data were analysed to observe the effects on pain-related disability and associated psychosocial variables, and to provide preliminary results and methodological consideration to a larger longitudinal observational study. xiv engaging with physical activity for CLBP. These data were analysed to observe the effects on pain-related disability and associated psychosocial variables, and to provide preliminary results and methodological consideration to a larger longitudinal observational study. Results The RCT showed no between-group difference for clinical outcomes or beliefs associated with adherence. Moreover, both groups showed increased patient beliefs after the initial session, despite the difference in structure and information provided. Adherence was high for both groups across the 8-week intervention to both practitioner-led and home-based sessions. These results suggest both individualised and general exercise programs are feasible for mild-to-moderate levels of CLBP. The cross-sectional observational study showed psychosocial variables associated with CLBP contribute to explaining the relationship between pain intensity and lower disability in a generalizable sample of people with CLBP. Higher functional self-efficacy and lower fear avoidance beliefs were reported as important variables in explaining the relationship between pain intensity and lower disability. Furthermore, engagement in physical activity for CLBP explained the association between higher functional self-efficacy and lower disability with reporting of worst pain in the last week. Engagement with physical activity for CLBP showed reduced levels of anxiety and small effects for functional self-efficacy, pain catastrophizing, and depression compared to participants who did not report the belief their physical activity was for their back pain. Methodological considerations for difference in reporting of current and previous pain intensity and the effect of physical activity for CLBP on functional self-efficacy, pain catastrophizing, anxiety, and depression were noted for the longitudinal observational study. These considerations will allow for this future research to explore if change in these variables explain causality in pain-related disability over time.

Date of Award	2017
Original language	English