Osteoarthritis and rheumatoid arthritis are common causes of joint pain and deformity. Osteoarthritis is a localized degenerative disease of the joints characterized by progressive damage to the articular cartilage of the synovial joints. Rheumatoid arthritis is a chronic systemic disease of unknown etiology characterized by persistent inflammation of the synovial membranes of the surrounding joints. These diseases are usually chronic and persistent pain that is tolerated to some degree by the patient, but when acutely exacerbated, the pain is often unbearable and there is no movement at all. Exercise and rehabilitation should not be neglected in the course of medication for any type of arthritis. It is common to encounter patients with arthritis who neglect exercise therapy along with medication, resulting in relief of joint pain, but increased joint deformity and loss of function. Exercise therapy for arthritis is misunderstood by many patients, including some physicians. Exercise is the most effective long-term way to improve joint function and slow the progression of disease. Exercise increases bone density, strengthens muscles, increases joint flexibility and compliance, helps stabilize joints, reduces morning stiffness, improves balance and endurance, and controls weight, but more importantly, it improves the mechanical stimulation and nutrition of joint cartilage and subchondral bone. For patients with arthritis, reasonable exercises include swimming, biking and other non-weight bearing exercises. If your own or objective conditions do not allow, you can sit on a bed or sofa to perform knee exercises by slowly straightening the knee joint in a recumbent or seated position and holding it for a certain amount of time such as 1 minute, relaxing it after the front of the thigh feels sore and fatigued, and so on repeatedly, 3 to 5 groups per day, 5 to 10 times per exercise, and gradually increasing the amount of exercise as physical strength allows. This repeated exercise can increase quadriceps muscle strength, enhance ligament tension, stabilize the knee joint, and stimulate cartilage and bone to improve nutrition and delay degeneration. In addition, exercises such as walking and jogging are weight-bearing exercises, which are suitable for people with mild joint degeneration and pain symptoms. Climbing and going up and down steps are further exercises that can be practiced in small amounts for those without pain symptoms, but too much can aggravate existing joint pain, especially for early patellofemoral arthropathy patients, which can be done appropriately after the quadriceps muscle strength has increased and pain symptoms have disappeared through non-weight-bearing exercises. If you are in too much pain to go out and exercise, don’t forget to do some soft stretching exercises and resume exercise early and gradually increase the amount of exercise after the condition has stabilized or the pain has been relieved by taking some analgesic drugs. The principles of exercise therapy are: gradual, long-term adherence, and adjustment according to joint symptoms and physical endurance at any time.