Physical activity and joint health: Implications for knee osteoarthritis disease pathophysiology and mechanics.

Knee osteoarthritis is experienced by hundreds of millions of people worldwide and is a major cause of disability. Although enhancing physical activity levels and the participation in exercise programmes has been proved to improve the debilitating illness of osteoarthritis, many do not engage in recommended levels of physical activity. One of the reported barriers to exercise engagement is the perception that physical activity can damage joint health and is attributed to the incorrect perception of 'wear and tear'. We posit that these perceptions arise from uncertainty and ambiguity generated from conflicting research findings. In this review, we explore the complex relationship between knee osteoarthritis and physical activity. We demonstrate how factors contribute to the uncertainty around the effects of physical activity on joint tissue metabolism, structure and function. The aim of this review is to demonstrate how a nuanced approach to the relationship between physical activity and knee osteoarthritis can help to dispel misconceptions, leading to better management strategies and improved quality of life for patients.