Osteoarthritis pain occur during activity in weight bearing joints such as hip and knee. This will lead to physical inactivity. As osteoarthritis is very common this will lead to significant public health concern. Physical inactivity lead to increased risk for heart disease and for obesity.Exercise capacity is poor in those with osteoarthritis of knee joint.
There is weakness of muscles over the knee joint in osteoarthritis. Since adequate muscle power is needed for joint protection muscle weakness results in further damage to the joint and decreases the exercise capability. Degree of weakness correlate with severity of joint disease and degree of limitation of mobility of joint.
Causes of muscle weakness
1.Decrease strength with age
2.As pain occur during activity ,there is tendency for physical inactivity this will lead to disuse atrophy
3.Alteration in gait as a protective mechanism decreases the load on affected joint and further decreases the muscle power.
Exercise program in osteoarthritis
For knee and hip joint osteoarthritis exercise improves the power and reduces the pain.
Effective exercise program are
1.Aerobic exercise
2.Resistance training
Resistance training is aimed at strengthening of muscle power. Exercise is maximum effective if the affected people are trained for their daily activities. Certain exercise increases the pain in joints they should be avoided. Strengthening of muscle by repeated bending of knee against resistance. It is done by flexing and extending the knee joint. Low impact exercise such as water aerobics and water resistance training is also found to be useful. This is better tolerated than loading exercise such as running. For getting maximum benefit from exercise patient should be referred to an exercise class or to a therapist to plan individual home based exercise regimen.
Major challenge in exercise program is lack of compliance. Trial showed 30 to 50 percentage of people stopped exercise after 6 months and less than 50 percentage continued after one year. Previous history of successful exercise is the strongest predictor for continued exercise in a given patient.
Role of physician
1.At each visit he should reinforce the exercise prescription.
2.Help the patient to identify obstacles in continuing exercise.
3.Identify convenient time for exercise daily.
It is also observed that calorie restriction along with exercise is very effective in decreasing pain. It is shown that early exercise and muscle strengthening help to improve the cartilage function on joint by MRI study.
