According to a report presented by the researchers of Istanbul University-Cerrahpasa and Mustafa Kemal University, strengthening QFM training alone found to reduce pain and improve function among knee osteoarthritis (KOA) patients, but in combination with Russian electrical stimulation or other electrotherapy modalities the outcomes are even better.

As the KOA patients have atrophy of the muscles, including the knee joint, the primary focus of exercise programs should be on the strengthening of quadriceps femoris muscle (QFM). To evaluate a particular exercise that improves the strength of the QFM and to explain the aspects of the training schedules was the primary purpose of the analysis and to find whether the strengthening of the QFM alone shows any significant efficacy among KOA patients was the secondary purpose of the study. 

A total of 1128 articles were selected by searching Cochrane, PubMed and PEDro. Ten studies with a moderate-to-high level of evidence were included for the analysis. Training groups exhibited no significant difference in the comparison of various strengthening exercises of the QFM. Although, strengthening of the QFM exercise training was better as compared to proprioceptive training. The added hot packs along with transcutaneous electrical nerve stimulation or shortwave diathermy or ultrasound showed an advantage over the isokinetic strengthening of the QFM alone. The only additional approach revealed a significant difference compared with the strengthening of the QFM exercise was the Russian electrical stimulation. Most of the selected studies showed that strengthening of the QFM exercises exert a considerable effect on the improvement of function and pain reduction.