Includes bibliographical references.

Introduction / Joost Dekker -- Epidemiology, pathogenesis, and clinical aspects of knee and hip osteoarthritis / Diana C. Sanchez-Ramirez, Joost Dekker, and Willem F. Lems -- Therapeutic options in osteoarthritis of the hip or knee / Martijn Gerritsen, Ramon E. Voorneman, Joost Dekker, and Willem F. Lems -- Risk factors for functional decline in osteoarthritis of the knee or hip / Marike van der Leeden, Cindy Veenhof, Leo D. Roorda, and Joost Dekker -- Neuromuscular mechanisms explaining functional decline / Martin van der Esch and Joost Dekker -- Behavioral mechanisms explaining functional decline / Jasmijn F.M. Holla, Martijn Pisters, and Joost Dekker -- Regular exercises in knee and hip osteoarthritis / Marike van der Leeden, Wilfred Peter, and Joost Dekker -- Exercise therapy targeting neuromuscular mechanisms / Jesper Knoop, Martijn P.M. Steultjens, and Joost Dekker -- Exercise aiming at behavioral mechanisms / Cindy Vennhof, Martijn Pisters, and Joost Dekker -- Comorbidity, obesity, and exercise therapy in patients with knee and hip osteoarthritis / Mariëtte de Rooij, Willem F. Lems, Marike van der Leeden, and Joost Dekker -- Summary and future directions / Joost Dekker.