Researchers from the Karolinska Institute have compared high-dose exercise therapy versus low dose in patients with symptomatic knee osteoarthritis. The study published in the journal Annals of Internal Medicine shows that both groups had similar results. However, high-dose exercise therapy produced superior results related to function in sports and recreation in the short term, with results tapering off at six months.
Osteoarthritis of the knee joint is associated with chronic pain, stiffness, reduced function and reduced quality of life. The treatment of choice is exercise, but few studies have investigated the optimal dose of exercise.
The hypothesis of the study was that a high dose is better than a low dose. The study was designed as a randomized multicenter superiority trial. 189 patients at four different centers, two in Norway and two in Sweden, were included in the study.
Patients randomized to the high-dose group performed eleven graded exercises lasting 70 to 90 minutes, and patients randomized to the low-dose group performed five graded exercises lasting 20 to 30 minutes. All patients received three treatments per week for twelve weeks.
The main outcomes were measured using the Knee Injury and Osteoarthritis Outcome Score (KOOS) every two weeks for three months and then again at six and twelve months. At all follow-up periods, KOOS scores improved in both groups, results that did not support the authors’ hypothesis.
The only differences favoring high-dose exercise were in the area of knee function during sports and recreation at the end of treatment and six months after the intervention and in the quality of life domain after six months.
The authors note that high-dose therapy could be preferable to low-dose therapy in the long run for people who lead active lives. Adherence could be an issue, however, as those in the low-dose group had almost perfect adherence to the intervention, while the high-dose participants had a higher dropout rate.
About half of the participants in both groups improved. Pain, quality of life and knee function improved. Because oyour study was designed as a superiority trial, meaning that although we could not show that high-dose treatment is better than low-dose, our results do not suggest that a low-dose exercise regimen is as beneficial as a high-dose regimen. “
Tom Arild Torstensen, physiotherapist and associated researcher at the Department of Neurobiology, Nursing and Society at the Karolinska Institutet and first author of the study
The study is funded by the Arthritis Association and has been carried out in collaboration with researchers at the University of Dalarna, Region Dalarna and the Norwegian University of Science and Technology.
Torstensen, TA, et al. (2023) High- versus low-dose exercise therapy for knee osteoarthritis A randomized controlled multicenter trial. Annals of Internal Medicine. doi.org/10.7326/M22-2348.