Low back pain, physical activity, and disability in older adults: a mediation analysis

Low back pain (LBP) is a disabling condition in older adults, with a significant socioeconomic burden, globally. Physical activity (PA) has also shown to be associated with disability however, a multi-variable relationship between pain intensity, PA, and disability, has not been explored in the older population. The objectives of this thesis were to i) review current literature of PA effects in older adults with LBP, and ii) explore if PA mediates the relationship between pain intensity and disability in older adults with LBP through secondary analysis of the BACE:Chiropractic – Netherlands dataset. A three-step model was developed using structural equation modelling to estimate relationship effects between 1) the crude relationship between pain and disability, 2) the relationship between pain and disability when mediated by PA, 3) the relationship between pain and disability when mediated by PA and adjusted for confounders (age, sex, and education). The literature review found no statistically significant effects of multicomponent exercise programs, or yoga or qigong on pain and disability in older adults with LBP. The secondary analysis found PA appeared to mediate the relationship between pain intensity and disability, however this effect was not statistically significant. The total proportion of this mediation effect accounted for 30% in the model, indicating PA does play a role in the progression to disability. The results of this thesis encourage further refinement of the mediation model. Furthermore, clinical trials are critically needed to determine the effect of PA and exercise on clinical outcomes for older adults with LBP.