The present study aims to promote research in the field of Physiotherapy, focusing on a health problem of maximum relevance, such as patellofemoral pain syndrome.

Although these treatments seem to be based on theoretical reasoning, the evidence for the efficacy of these interventions is not well established. Therefore, we select from among all the therapeutic tools available in physiotherapy, a procedure of therapeutic physical exercise.

Main objectives:

To know the efficacy of a therapeutic physical exercise protocol in the reduction of pain and the improvement of functional disability in patients with patellofemoral pain syndrome (PFPS).

Secondary objectives:

• Quantify the reduction of pain in the anterior aspect of the knee in patients with patellofemoral pain syndrome (PFPS), after treatment with monopolar capacitive diathermy by radiofrequency.
• To evaluate the improvement of functional disability in patients with patellofemoral pain syndrome (PFPS), after treatment with monopolar capacitive diathermy by radiofrequency.

Study hypothesis:

The treatment of patellofemoral pain syndrome (PFPS) with a therapeutic physical exercise protocol produces statistically significant changes in the reduction of pain and functional disability and the normalization of the anthropometric values of the joint balance of the knee

At first, a meeting will be held with the patients under study where they will be informed and any doubts that may arise in relation to the investigation will be resolved. In addition, the correct adaptation of these to the inclusion and exclusion criteria of our study will be verified. Subsequently, they will be given individually the informed consent prepared expressly for the present study, the doubts arising with respect to this one will be resolved and their signature will proceed. At this time, and individually again, we will proceed to the development of the Clinical History of Physiotherapy where only the information necessary for our study will be collected.

To emphasize in this point that the participants will grant their consent for the treatment of the data obtained for scientific purposes, according to the legal norms.

Next, the patients will be randomly assigned to two groups: control group and experimental group. The randomization of the sample was done through the EPIDAR software in version 3.1 between the Experimental Group and the Control Group Subsequently, the evaluations and measurements of the study variables will be carried out by the research team.

CONTROL GROUP: You will be provided exclusively therapeutic exercises protocol to develop supervised by Physical Therapist that you must perform following a daily activity for three weeks. They will be evaluated at the end of that period and six moths later in order to have at least three timepoints to evaluate.

EXPERIMENTAL GROUP: After the initial evaluation, the first 10 treatment sessions will be developed at the rate of five daily sessions in the first week, three sessions on alternate days in the second week and two sessions on alternate days in the third week (3 weeks in total), applying the monopolar capacitive diathermy with radiofrequency in the anterior aspect of the knee, in dynamic application in one of the members: affect or randomized (uni or bilateral pathology, respectively). This diathermy will be combined with a therapeutic exercise program supervised by a Physiotherapist.

The treatment is administered with a Diathermy equipment and inductive electrodes of 100 W peak power, with a frequency of application of twice daily with a dose submitis (grade I), for 10 min, with a frequency of repetition of the impulses of 46 Hz and a pulse duration of 0.2 ms

After the tenth treatment session all the measurements will be repeated following the same environmental conditions as at the beginning and by the evaluators themselves to the components of both groups.Those measurements will be evaluated at the end of that three weeks period and six moths later in order to have at least three timepoints to evaluate.

Inclusion Citeria:

1. Age from 18 to 55
2. . Patients with anterior knee pain were referred by a primary care physician at a public health center in southern Spain. Those participants with a self-reported pain intensity = 30 mm on the Visual Analog Scale (VAS) and a score <45 points in personal psychology The Apprehension Scale (PPAS) were invited to participate. The PPAS is a valid, reliable and easy-to-use tool for assessing the apprehension of subjects to receive electrical stimulation therapy.

Exclusion Criteria:

1. Any contraindication for the use of MDR.
2. Present cognitive alterations.
3. Have undergone conservative or surgical treatment of the knee in less than 6 months.
4. Having received injections of corticosteroids or hyaluronic acid; impaired cognition or communication; and be involved in an ongoing medical-legal dispute.