An investigation of the relationship between movement and pain

Abstract

Pain is associated with altered movement (or motor adaptation) that, despite short-term benefit, has been hypothesised to be a contributor to the transition from acute to chronic pain. However, data supporting this theory have been drawn primarily from cross-sectional studies, with limited longitudinal investigations. Characterising motor adaptation over time, in the transition from acute to sustained pain, is essential in order to understand the role of motor adaptation in the development of chronic pain. Further, the physiological basis of motor adaptation to pain is poorly understood. While proprioception and psychological factors have been proposed as key mechanisms underlying motor adaptation, the influence that pain has on proprioceptive function is not well known, nor is it known how psychological factors interact with adaptations in the primary motor cortex (M1), a key area of the brain involved in movement. While the influence of pain on movement may have implications for the development of chronic pain, movement through exercise is considered a first-line intervention for pain. However, despite exercise being recommended in all current clinical practice guidelines, no information exists as to whether exercise should be performed pain-free or into pain. Given the lack of evidence-based guidance for the pain-provoking nature of exercise, this raises the question of how this issue is managed in clinical practice. Research to date has not examined how Australian health professionals prescribe exercise (type and pain provoking nature) for the treatment of musculoskeletal pain. Therefore, the broad aim of this thesis was to enhance our understanding of the relationship between movement and pain. This thesis includes eight chapters, beginning with an introduction (Chapter 1) that presents a review of the literature that pertains to the research questions covered, followed by five research papers (Chapters 2-6), a discussion (Chapter 7) that evaluates the findings of the studies as a whole and makes recommendations for future research, and a reference list (Chapter 8) that pertains to the in-text references cited throughout this thesis. Please note that of the five research papers, four have been embedded in their published format, and one embedded according to the journal it has been submitted to, which is under review. Each published manuscript has independent numbering of pages, figures, and tables, and an independent reference list. The page numbering of this thesis therefore excludes the pages containing embedded published manuscripts. Ethical approval for the studies reported in Chapters 2, 3, 4, 5, and 6 was obtained from the Western Sydney University Human Research Ethics Committee. An organisational chart that outlines the studies conducted and the chapters to which each relates is included on the following page.

Date of Thesis submission	2020
Original language	English