Effects of isometric exercise using biofeedback on maximum voluntary isometric contraction,pain, and muscle thickness in patients with knee osteoarthritis

[Purpose] The purpose of our study was to investigate the effects of isometric exercisesusing electromyographic biofeedback (EMGBF) and ultrasound biofeedback (USBF) on maximumvoluntary isometric contraction (MVIC), pain assessed by the Visual Analogue Scale (VAS),and vastus medialis oblique (VMO) thickness in patients with knee osteoarthritis (OA).[Subjects and Methods] Thirty females over 65 years of age who had been diagnosed withknee osteoarthritis were recruited and randomly assigned to three groups, each comprisingof 10 subjects. The Subjects in the EMGBF training and USBF training groups were trainedwith the corresponding physical training exercise program targeting the vastus medialisoblique, whereas the subjects in the control group were treated with conventional physicaltherapies, such as a hot pack, ultrasound, and transcutaneous electrical nervestimulation. Subjects in each group were trained or treated for 20 min, 3 times a week for8 weeks. [Results] The MVIC in the EMGBF and USBF training groups was significantlyincreased compared with that in the control group, and the VAS score (for measurement ofpain) in the EMGBF and USBF training groups was significantly decreased compared with thatin the control group. Only the EMGBF training group showed a significantly increased VMOthickness compared with before training. [Conclusion] These results suggest that USBFtraining is similar to EMGBF training in terms of its effectiveness and is helpful fortreating patients with knee OA.Key words: Conventional physical therapy, Electromyographic biofeedback, Ultrasound biofeedback