Though hyperthermia by microwave is widely used towards knee OA, there is little evidenceregarding the efficacy. Radiofrequency hyperthermia has beenprimarily used for malignanttumorsand is known for its effectiveness both in removing cancerpain and in minimizingtumors. The purpose of this study is to compare and investigate the therapeutic effect ofhyperthermia using radiofrequency treatment and hyperthermia by administering microwavestowards knee OA.Objectives: Sixteen cases of knee OA patients (Kellgren and Lawrence grade II and III)were divided into a radiofrequencyhyperthermia therapy group (RFgroup: n = 9) and anmicrowave hyperthermia therapy group (MW group: n = 3).Methods: Electromagnetic radiation was conducted on the OA knee3 times in 1-weekintervals at 8 MHz, 200 W, for 20 min using a Thermotron-RF8 (manufactured by YamamotoVinita, image) for the RF group and at 2.45 GHz, 100 W, 10 min using a MicroradarKTM-250 (manufactured by Ito Physiotherapy and Rehabilitation) for the MW group. Clinicalevaluation was conducted using the Lequ