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

A Prospective Randomized Study Comparing the Outcome of Electrical Stimulation of Vastus Medialis Obliquus Muscle and Physical Therapy Vs Only Physical Therapy but No Electrical Stimulation in Patients with 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.

Inclusion Criteria:

• Bilateral/unilateral anterior knee pain for more than 3 moths
• Age of patient 18 to 40 years
• At least 3 of the 4 following criteria present: pain associated with prolonged sitting with knees bend, pain with going downstairs, kneeling and squatting or sports activities
• No h/o injury
• No h/o surgery to the knee

Exclusion Criteria:

• H/o patellar dislocation or subluxation
• Associated bursitis, tendinitis in periarticular area
• Ligamentous problems
• Intra-articular pathology
• Pregnancy (patient reported pregnancy, in case of doubt patient will be referred to their OBG/GYN physician to exclude the pregnancy)
• H/o knee surgery
• Oral or intraarticular administration of steroid medication with in last 3 months
• Patients with implanted devices like pacemaker