This is the editor's interpretation of the above paper published in the orthopaedic literature in 2006 - our attempt to make relevant medical articles accessible to lay readers. If you want to read the original it is easy to ask your librarian to obtain a reprint for you from any medical library.
The author notes that knee OA affects about one third of all older adults in the USA, with pain being the principle symptom affecting their quality of life. The inactivity consequent on the pain leads to muscle weakness, wasting and deconditioning, and some researchers postulate that the muscle weakness itself can further exacerbate the pain, suggesting that if the pain is successfully managed then people would suffer less decline in their ability to undertake their daily activities as they get older.
The author notes that as medication and surgery have been found to yield mixed success attempts have increasingly focused on identifying and developing more effective pain management strategies. Of these, exercise therapy is getting considerable interest as several groups of researchers had demonstrated significant improvements in pain symptoms and physical function in older adults with OA of the knee.
A problem, however, has been that despite these positive findings most older adults with knee OA remain sedentary, and even when they are persuaded to enter an exercise programme there is a high pull-out rate. This author set out to try and find out why this was so. He reviewed many studies and decided to focus on 18 trials where people of 50 years plus and with knee OA had been entered into a regular, structured, repetitive exercise programme lasting several weeks to several months. These trials had included:
Aerobic training, strength training or a combination were all found to improve pain symptoms, although the magnitude of the improvement varied across the 18 trials. The author suggests that one reason for this might be that the studies varied in the parameters withing the pain-scoring systems used to evaluate the pain.
The author of this paper raised a number of issues -