The Effects of Closed Kinetic Chain Exercise Using EMG Biofeedback on Functional Characteristics of PFPS Patients` Lower Extremity Muscles

This study aimed to examine the effects of closed kinetic chain exercise using electromyography (EMG) biofeedback for selective strengthening of the vastus medialis oblique (VMO) on functional characteristics of lower extremity muscles in patellofemoral pain syndrome (PFPS) patients. The subjects of this study were 30 PFPS patients and they were equally and randomly assigned to a control group (I), a closed kinetic chain exercise group (II), or an EMG biofeedback closed kinetic chain exercise (III). They received intervention three times per week (for 30 minutes per each time) for six weeks. EMG was used for measurement. According to the study result, there were significant differences groups II and III compared to group I in median frequency (MDF) and the VMO/the vastus lateralis (VL) muscle activity ratios (p<.05). According to the result, PFPS patients’ improvement in muscle control and response ability using EMG biofeedback during closed kinetic chain exercise enhanced their muscle functions.