A Phase 3 interventional study of EMS and Physical therapy in Patellofemoral Pain Syndrome, sponsored by Northwell Health. Recruiting at 1 site in United States. Open to participants aged 18 Years to 40 Years. Per ClinicalTrials.gov, last updated 2026-10-07.
Sponsored by Northwell Health · Phase 3, Interventional, and Treatment
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.
295 studies on the registry are indexed under Patellofemoral Pain Syndrome; 75 are open to participants now.
This study's planned enrollment of 92 is above the median of 45 across 242 interventional studies indexed under Patellofemoral Pain Syndrome.
Browse Patellofemoral Pain Syndrome studies →Northwell Health is the lead sponsor of 463 studies on the registry; 109 are open to participants now.
Of its 40 completed or terminated interventional studies of FDA-regulated products, 20 (50%) have results posted.
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Exclusion Criteria:
Group 1: Electrical Muscle stimulation (EMS) and Physical therapy (PT).
Device: EMS · Other: Physical therapy
Group 2: Only Physical therapy (PT).
Other: Physical therapy
The EMS device Flex MT Plus (Electrostim Medical Services Inc. Tampa, FL) is a neuromuscular stimulator. It is approved by the FDA. The Electrical muscle stimulation (EMS) applied to vastus medialis obliquus (VMO) muscle for 20 minutes, 3 times daily and it would be 5 times a week for 12 weeks at 40 Hz. The pulse duration will be 0.26ms, at 5 seconds on and 10 seconds off.
Standard physical therapy exercises
Kujala patellofemoral score.
Assessment will be done at each visit (pre-treatment, post-start treatment 3 weeks,, 6 weeks, 12 weeks, 6 months and 12 months) based on Kujala patellofemoral score. The Kujala score assesses following points: Limp, support, walking, stairs, squatting,running, jumping, prolong sitting with knee flexed,pain,swelling,abnormal painful kneecap movements, atrophy of thigh and flexion deficiency. Repeated measures linear regression models will be used to compare the two treatment arms with respect to knee function, pain score, and muscle strength from baseline to 12 months. Total duration of study is two years. We intend finish enrolling 92 patients by the end of one year after start of study. But each patient will be followed for total 12 months period. If any patient enrolled at 1 year mark after start of study , he will be followed for one year.
Time frame: 2 years. Total duration of study is two years. But each patient will be followed for total 12 months after enrollment. If any patient enrolled at 1 year mark after start of study , he will be followed for one year. So total duration of study is 2 years.
Visual analog pain scale (VAS) pain scale during activities of life
VAS scale of 1-10 will be used to evaluate knee pain. 1 being mild and 10 being worst.
Time frame: 2 years
Isometric strength measurement of knee
Isometric strength will be measured using dynamo-meter.
Time frame: 2 years
Secondary outcome measure would be how many return to sports activity.
Secondary outcome assessment will be to see how many in EMS+PT group and how many in PT group returned to their previous activity level of sports without any pain after completion of treatment.
Time frame: 2 years
At what point of time they returned to their sports activity
It will be also noted and compared between the groups at what time period after the start of treatment they returned to their regular sports activities. We hypothesize that EMS group might return early.
Time frame: 2 years
Plan to share: No — No patient data will be shared.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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