[Purpose] The purpose of our study was to investigate the effects of isometric exercises
using electromyographic biofeedback (EMGBF) and ultrasound biofeedback (USBF) on maximum
voluntary 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 with
knee osteoarthritis were recruited and randomly assigned to three groups, each comprising
of 10 subjects. The Subjects in the EMGBF training and USBF training groups were trained
with the corresponding physical training exercise program targeting the vastus medialis
oblique, whereas the subjects in the control group were treated with conventional physical
therapies, such as a hot pack, ultrasound, and transcutaneous electrical nerve
stimulation. Subjects in each group were trained or treated for 20 min, 3 times a week for
8 weeks. [Results] The MVIC in the EMGBF and USBF training groups was significantly
increased compared with that in the control group, and the VAS score (for measurement of
pain) in the EMGBF and USBF training groups was significantly decreased compared with that
in the control group. Only the EMGBF training group showed a significantly increased VMO
thickness compared with before training. [Conclusion] These results suggest that USBF
training is similar to EMGBF training in terms of its effectiveness and is helpful for
treating patients with knee OA.