Inactivity produces and progresses the signs and symptoms associated with arthritis, namely muscle weakness and atrophy, decreased flexibility and cardiovascular fitness, osteoporosis, depression and lowered pain threshold. Surgical treatments are the final therapeutic procedures to overcome the disability caused by OA knee but are not the ideal method as it increases the risk of other forms of illness, blood loss, hospital stay and prolonged rest to the joint postoperatively. The surgical options include:
Non-surgical therapy of knee OA often focuses on a pharmacological approach and includes analgesic agents or non-steroidal anti-inflammatory drugs (NSAIDs) . This type of therapy may imply serious health hazards because of adverse gastrointestinal effects. Overweight, and especially obese, persons run a high risk of OA in the knee and probably also the hips and hands, although the mechanism by which obesity causes OA is poorly understood .
According to Greene.B and Samlin.S (2003) exercise is "systematic and planned physical movements or physical activities to prevent further damage, promote functions and enhance the level of fitness and well-being". Exercise increases the mobility of joint, releases endorphins, and may help to reduce weight in conjunction with a low calorie diet. Fitzgerald PL (1985) and Ike RW et al (1989) show that there may be a significant deceleration in the disease process if a healthy lifestyle is incorporated which takes into account healthy eating appropriate to the body composition, and exercise training.
The load on the knee joint can either be reduced by reducing the overall weight of the individual or increasing the muscle mass of the quadriceps and the hamstring muscles which provide the support to the joint. In the past it was believed that rest would benefit inflamed joints and promote healing. However, recent studies have shown that people with OA of the knee can tolerate weight-bearing exercise such as walking. In fact, studies show great benefits in exercise for people with OA. A trial done for 18 months by Messier et.al (2004) found that exercise in conjunction to a low calorie diet produced significant decrease in morning stiffness and increase in physical activity level
In a randomized control trial of 439 adults living in community with knee OA O’Reilly SC, Muir KR, Doherty M (1999) compared groups that had 18 months of aerobic walking with programs of resistance exercise and of health education. Both exercise groups improved in physical performance, knee flexion strength, and decreased pain compared to the education group. The study of outcomes by percentage of sessions performed showed significant improvements in disability, pain and walk scores associated with increasing compliance.
A consequence of osteoarthritis knee there occurs limitation in the range of motion and lack of strength. The main clinical presentation of OA knee is varus deformity and grade 1 laxity of the lateral collateral ligament. So the goal should be to strengthen the muscles and tendons of hip abductors and stretching the hip adductors and this is brought about by placing the resistance on the knee rather than the ankle. During the later stages of the disease the goals should concentrate to increase the strength, range of motion, functional capacity including balance and co-ordination to prevent falls due to knee instability, and prevent osteoporosis due to non weight bearing. Activities such as stepping, resisted exercises of the knee joint, swimming, cycling, and walking should be emphasised.
Knee strengthening exercises should involve supervised exercise protocol (S. B. King, M. A. Minor 2003) for 5 weeks at a frequency of two times a week, a duration of 30 mins and the volume of 8-10 exercises; 8-12 lifts of a load of 60-80% of 1RM to produce local fatigue in 8-12 repetitions; 1-3 sets as tolerated, maximal isometric knee extensions of 24 repetitions, stationary bicycling at a moderate speed for 2 mins and functional exercises for 1-3 mins. After 5 weeks of supervised exercise protocol, home exercises for functional independence must be prescribed 2-3 exercise at a frequency of 3 days per week.