Osteoarthritis (OA) is a chronic prevalent condition that affects the synovial joints and can lead to disability. There is no single treatment that is known to cure OA. Most treatments have aimed at reducing symptoms or slowing the progression of the disease and its consequences. Exercise therapy is a common intervention in treating OA, with primary aims of improving functional movement and managing the problems associated with abnormal functional movement. We review the underlying process of exercise treatment and its importance for OA disability. A brief description of OA disease and an OA disability model are introduced, and then the importance of exercise and trends in prescribing exercises for OA are discussed. Finally, future directions and suggestions for research in this field are described.