Comparing the Outcome of Electrical Stimulation and Physical Therapy in Patellofemoral Pain Syndrome

The purpose of study is to evaluate the efficacy of the electrical muscle stimulation (EMS) device in patients with patellofemoral pain known as anterior knee pain. Usual treatment for it is physical therapy (PT). We want to evaluate and see if adding the electrical muscle stimulation will fasten the recovery and improved outcome in patellofemoral pain syndrome. Half of participants will receive EMS and PT while other half will receive PT only.

The patellofemoral pain syndrome also known as anterior knee pain is a common entity in young athletic population. In patellofemoral knee syndrome, one of the theory is that the vastus medialis obliquus muscle is weak. To strengthen the muscle, physical therapy exercises are commonly used. This study evaluates addition of the electrical muscle stimulation device.The electrical muscle stimulation device "Flex MT Plus" (Electrostim Medical Services Inc. Tampa, FL) is a FDA approved device and has been used in knee for other conditions like treating for weakness associated with knee injuries or after knee surgeries. It has shown to improve the outcomes in above mentioned conditions. Its efficacy has been tested in patellofemoral pain syndrome but in smaller sample size. We intend to test it in larger sample size patient population. Bily et al (2008) (reference #1) published their results on patellofemoral pain syndrome comparing EMS +PT to PT only and found that overall significant improvement in outcome score in all patients but when compared between the groups there was no difference. But there sample size was 19 patients in each group. Small sample size was one of the limitation of their study. We intend to collect 46 patients in each group to find significant difference based on power analysis.