Osteoarthritis (OA) is a common chronic disorder of the joints that predominantly affects older people but can also affect younger individuals following joint injury. In normal joints, cartilage covers the surfaces of the joints and helps to absorb shock and allows smooth movements. In OA, the cartilage of the affected joint wears down until little or none remains, and the opposing bones rub together. Extra new bone may also form around the joint surfaces. These effects cause pain and restrict joint movement. The most common joints affected by OA are those of the hips, knees, big toe, spine and hands.
A health professional can generally diagnose OA on the basis of reported symptoms and physical examination of the joint. Six key features allow a confident diagnosis including persistent knee pain, knee stiffness for less than 30 minutes, reduced function, joint crepitus, restricted motion and bony enlargement. Several tests can aid in diagnosis if necessary. X-rays may show narrowing of the joint space (from cartilage loss), bony outgrowths, thickening of the bone under the cartilage, joint misalignment or cyst formation. An MRI (magnetic resonance imaging) scan can demonstrate early changes in the cartilage that cannot be seen on X-ray, and changes in other joint structures such as bones and ligaments. A full blood count and the erythrocyte sedimentation rate (the rate at which the red blood cells settle to the bottom in a blood sample) are usually normal, but these measures can be important to rule out other inflammatory conditions. Importantly, changes seen on X-ray or MRI do not correspond well with the pain that a person may experience. For example, a person can have mild changes on X-ray, but experience severe pain, and vice versa.
All clinical guidelines recommend exercise to manage OA. Considerable research shows that exercise benefits people with a wide range of disease severities, including people with severe pain or changes seen on X-ray. Overall, exercise is as effective in relieving symptoms as are pain medications and anti-inflammatory drugs. However, exercise is safer and has fewer side effects. Exercise can help to: reduce pain, increase muscle strength, improve the range of joint motion, improve balance, prevent de-conditioning (loss of fitness and muscle wasting), improve physical function improve wellbeing.
Many types of exercise are beneficial for people with OA. The choice of exercise should take into account your age, functional ability, other health conditions and personal preference. Choose a type of exercise that you enjoy and can easily incorporate into your daily life. Strength (resistance) training and/or aerobic exercise are recommended forms of exercise.
Strength training can be performed at home or at the gym. The thigh, hip and calf muscles, which are important for daily function, are often weak in people with OA. Resistance can be applied with weights, elastic tubing or body weight.
Aerobic exercise can be performed by yourself, with a friend or as part of a group. Activities may include walking, cycling, or using a rowing machine or a seated stepper. High-impact exercises, such as jogging, place high loads on joints and therefore should be avoided. Water exercise can be useful before progressing to land-based exercise.
Other types of beneficial exercise include tai chi, balance exercises, and stretching to improve the range of joint motion and flexibility. Before starting a physical exercise program, it is recommended that you receive a comprehensive assessment by an appropriately qualified health care provider. This assessment should include clinical evaluation of your OA, and should identify any other health conditions that may be worsened by exercise.