This thesis investigated the relative effects of manual therapies and warm-water exercise on the health-related quality of life (HRQOL) of people with common arthritides (rheumatoid arthritis [RA] or osteoarthritis [OA]). The thesis comprised three linked clinical studies and a pilot study. The three clinical studies were randomised, unblinded, controlled, clinical trials of three or four groups with repeated measures. The Pilot Study concerned validation of the data collection tools prior to use in the clinical studies.