Along with particular knee exercises, emphasis should also be towards maintenance of the cardiovascular fitness and include aerobic exercises at a frequency of 3-5 days per week at 60-80% maximum heart rate for duration of 20-60 mins continuously. Range of motion exercises in the form of gentle stretching and full range flexion and extensions should be done daily to improve and maintain the full range mobility at the knee joint. Due to the laxity of ligaments around the joint there occurs instability of the knee joint leading to an increase in falls. To overcome this balance and co-ordination exercises must be incorporated in the form of line walking with or without support depending on the level of independence, tilt table exercises, and body awareness training.
As there is a strong relation between obesity and OA knee efforts must be made to loose weight and maintain a recommended BMI especially for women as they tend to be more susceptible to OA knee. For this low intensity long duration exercises at 50% of the maximum heart rate must be administered till the target weight is achieved. Interventions such as walking for 60 mins on a treadmill or on plain surface, swimming, along with a low calorie high fibre diet can be administered as exercise alone can not produce the desired effects.
The acute stage of the disease is usually associated with local inflammatory changes such as local rise in temperature, swelling and pain during weight bearing. Therefore care must be taken to avoid any resistance training during this phase of the disease and emphasis on prevention of deformity. Although isometric knee exercise every day at a frequency of 5 contractions per hour, and slow rhythmic mid range dynamic free movements can be performed depending on the level of pain. Care also is taken not to over exercise as it may lead to delayed onset muscle soreness and increase the level of pain. Walking without support must not be attempted during this phase as it may result in falls due to instability. Even a slight stumble may result in micro trauma to the ligaments surrounding the knee joint. Stair climbing and walking on elevated tread mill or uphill should also be discouraged as it may increase the level of pain.
Exercise is also strongly contraindicated if co-morbidity in the form of cancers (malignancies) and severe cardiovascular diseases, in the form of malignant hypertension or aneurysm ect. exists. Any undertaking of an exercise program should be consulted with the physician. Therefore a pre-exercise screening must be performed to rule out any hazards.
The physical barriers to exercise participation in OA knee is the pain and stiffness. This can be reduced by application of heat or cold before the exercise program. Heat induces local relaxation of muscles, release endorphins and blocks the pain gate thus reducing pain and stiffness.
Other barriers to exercises are the cost of visiting a physical therapist or a trainer for the whole exercise program. The cost of physical training can be reduced considerably by teaching the exercise, frequency and duration at one visit and instructing the patient to continue the exercises at home.
A psychological barrier to exercise is when the patient feels that exercise may worsen his/her condition. Proper education on osteoarthritis by self help courses and web site e.g. http://www.arthritis.org ; (telephone: 888-879-7890) can provide the necessary information. A study done by K R Lorig and colleagues in 1985 demonstrated that monthly telephone communications with patients were cost-effective and were associated with good clinical outcomes. In this way patient education can help them to participate actively in exercise programs.
Lastly motivation of the patient towards any exercise program may pose a barrier. The motivational status may be improved by group therapies including a number of patients with OA knees so as to socialise within group and compare the level of disabilities.
Ms Annapurna Chandani,
B.P.T (India) Msc Exercise Science, (U.K)
Physiotherapist (IAP Reg No.9636)