Radiofrecuency and Supervised Exercise Versus Supervised Exercise in the Treatment of Patellofemoral Pain Syndrome.

This study will analyze the effects of a non-invasive radiofrequency diathermy device added to knee exercises on the symptoms of patellofemoral pain syndrome. For this aim, a randomized clinical trial will be carried out with a control group that will perform supervised exercises and an experimental group that will add radiofrequency diathermy to supervised exercises. Diathermy treatment will be performed along three weeks, ten treatment sessions in total, while supervised exercises will be performed daily.

Outcomes to measure will include pain, knee function and quality of life

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 EPIDAT 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: them will be provided exclusively therapeutic exercises protocol that you must be performed supervised by a physiotherapist following a daily activity for three weeks.

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 dielectric diathermy by 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 the same supervised therapeutic exercise program of the control group.

The treatment is administered with a pulsed non-invasive radiofrequency device with 30V peak power along 12 minutes, with a dose submitis (grade I) for three weeks. The first week, daily treatment will be perform from Monday to Friday, second week on Monday, Wednesday and Friday and the third week on Monday and Thursday.

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.

Eligibility Criteria:
Inclusion Criteria:

* Patients diagnosed with patellofemoral pain syndrome more than 6 months old.
* Have an age between 18 years and 50 years.
* Adult 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) \[bathrobe 2017\], 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 \[bathrobe 2005\].

Exclusion Criteria:

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