Date Approved


Graduate Degree Type


Degree Name

Physical Therapy (M.S.)

Degree Program

Physical Therapy


Patellofemoral Pain Syndrome (PFPS) is a major cause of knee pain and is caused by lateral patellar tracking. Treatment consists of strengthening the vastus medialis obliquus (VMO). While many exercises strengthen the VMO, simultaneous vastus lateralis (VL) strengthening often occurs and patellar malalignment remains. The VMO must, therefore, be strengthened independently or to a greater extent than the VL. Thus, the VMO:VL ratio of activity must be considered rather than VMO activity alone. This study compared isometric knee extension electromyographically at 0, 20, 60, and 90 degree angles to determine which angle produced the greatest VMO:VL ratio of activity. Results of this study indicated no significant differences among angles tested for VMO:VL ratio during isometric knee extension. Further research is needed to investigate the possibility of significant associations between VMO:VL ratios and gender, pathology, and angles not included in this study.


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