Osteoarthritis of the knee: Why does exercise work? A qualitative study of the literature

► Literature was systematically reviewed for models explaining exercise effects in OAk. ► 73 Key points were identified which were subdivided into 16 theoretical concepts. ► Concepts were ordered as neuromuscular, peri-/intra-articular, psychosocial and health. ► We provide some recommendations when designing exercise therapy in OAk patients.