Introduction: the management of Patellofemoral Pain (PFP) is focused on therapeutic exercise (TE) to improve muscle strength and motor control. Recent studies suggest that the addition of radiofrequency diathermy (RFD) obtain greater short-term improvements in knee pain than TE alone. As there is no follow up data, the aim of this research is to assess the long-term effects of adding RFD to TE on pain, function and quality of life on PFP patients.

Methods: a single-blind randomized controlled trial will be conducted. Participants diagnosed of PFP will be allocated in either a TE group or a RFD+TE one. Sociodemographic data, knee pain, and lower limb function will be collected. Each group will performed 20 min of daily knee and hip supervised TE along three weeks with the addition of ten sessions of RFD for the RFD+TE group.

Inclusion Criteria:

• Subjects between 30 and 50 years old without radiological findings of osteoarthritis.
• Subjects referring during the last month almost three points of pain in the anterior surface of knee measured with Visual Analogue Scale.

Exclusion Criteria:

• Subjects with contraindications for the treatment with radiofrequency diathermy (tumors, use of pacemakers or any other implanted electronic device, thrombophlebitis or deep venous thrombosis, pregnancy, fever, active tuberculosis, infections and rheumatoid arthritis).
• Subjects who have received corticoid or hyaluronic acid or platelet-rich plasma injections treatment in the knee.

Participants were unaware of the treatment group. Researchers in charge of assessment were blinded. Investigator in charge of data analysis was blinded about treatments. Only care providers known about the different treatments