Resistance exercises (RX) are known to be an effective intervention both for reducing pain and for enhancing physical function and self-efficacy. It is also helpful in restoring muscle strength and joint mechanics. However, there is lack of evidence showing the methodological quality of resistance training interventions for knee osteoarthritis (OA) management.

Review studies published up to August 10, 2015, were searched on MEDLINE, PubMed, Embase, and Physiotherapy Evidence database. Osteoarthritis, knee, and muscle resistance exercise were the terms used for searching the studies. The criteria for inclusion of studies was muscle resistance training as the primary intervention, randomized controlled trial design, the presence of a muscle conditioning intervention and a non-exercise group and patients with knee OA. 34 studies met the inclusion criteria.

Article screening was done independently by two reviewers. The methodological quality was estimated based on the principles of resistance training and separately for the reporting of adherence using a specifically devised scoring system. Rating for each article was done accordingly. A total of 34 studies reported a strength training focus of the intervention; but, the principles of resistance training were illogically used and incompletely described in all the studies. 28 studies included methods for adherence monitoring, but only 13 reported adequate detail to assess the average dose of exercise.

The efficacy of muscle resistance exercise in the management of knee osteoarthritis cannot be adequately explained due to these findings. These findings may pose a great challenge for clinicians and healthcare professionals to understand whether these findings are due to lack of effectiveness of muscle resistance interventions, or due to deficiencies in treatment prescription and patient adherence. Adequately designed future studies are needed to be conducted with an aim to establish the effectiveness of resistance training interventions in knee OA patients.