MedicalResearch.com Interview with:
Carsten Juhl, PhD, MPH
Forskningsenheden for Muskuloskeletal Funktion og Fysioterapi (FoF)
Institut for idræt og biomekanik
MedicalResearch.com: What are the main findings of the study?
Dr. Juhi: The main findings of this study including 48 RCTs with more than 4000 patients were that
-  exercise therapy programs focusing on a single type of exercise were more efficacious in reducing pain and patient-reported disability than those mixing several types of exercise with different goals within the same session;
-  the number of supervised sessions enhances the benefits of the aerobic exercise;
-  exercise focusing on the knee extensor muscle strength only, may increase the benefits of resistance training and
-  exercise seems to be effective therapy for knee osteoarthritis, regardless of age, sex, BMI, radiographic status or baseline pain.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Juhi: It was actually surprising that interventions with different type of exercise within the same exercise session were less effective than sessions with only a single exercise type and I think that this should be investigated further in direct comparisons. Furthermore we expect that increasing intensity of strength training had an impact on reduction of pain and disability, but this was not confirmed in the study and the one study comparing strength with high and low intensity.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Juhi: In order to achieve the best effect of exercise therapy for patients with knee osteoarthritis exercise interventions should focus on a single type of exercise. In patients with poor aerobic capacity and muscle strength, aerobic exercise and strength training should be performed on different days in order to achieve the best effect. These exercise programs should be supervised and carried out at least three times a week.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Juhi: The above recommendation should be confirmed in trials with a direct comparison on single versus multiple exercise type; exercise two versus three times or more a week..
· Furthermore the dose-response relationship in exercise for knee osteoarthritis should be investigated in individual patient data meta-analyses
· In order to investigate the impact of different exercise program characteristics it is important that future exercise interventions are described in details concerning intensity, length of exercise program, number of supervised sessions, duration of individual supervised sessions, and number of sessions per week.
Impact of exercise type and dose on pain and disability in knee osteoarthritis: A systematic review and meta-regression analysis of randomized controlled trials
Arthritis Rheum. 2013 Dec 18. doi: 10.1002/art.38290. [Epub ahead of print]
Juhl C, Christensen R, Roos EM, Zhang W, Lund H.