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 (2 trials)
- strength training (9 trials)
- combined aerobic/strength training (5 trials)
The author of this paper raised a number of issues -
- clearly clinicians will want to know what type of exercise to prescribe - strength training or aerobic training or a combination? The author points to a key paper that suggests that both strength and aerobic training should be prescribed.
- another issue is whether or not the exercise programme should be combined with a weight-reduction programme in the obese patient. The author points to a recent trial that does support this.
- which is more efficient - a home-exercise programme or a centre-based programme? Among the studies reviewed there were several that examined this issue - again there was variability in the findings. This author concluded that although in general both resulted in improvements in pain, the cost of a centre-based exercise programme and the fact that most older adults prefer a home-based programme point to a home-based programme being preferable, as long as there is some sort of structured support and education involved. Better still seems to be starting a programme in a centre and later transferring the patient onto a home-based programme.
- to what extent can pain improvements be translated into functional improvements? The studies again varied widely in answering this question, and this author suggests that the different scoring systems used might again be confounding the true answer.