This study is a randomized controlled clinical trial using a blind evaluator. Fifty-one volunteers were selected from 50 years to 70 years, obeying the following criteria: diagnosis of knee OA grade II and III through the radiographic classification of Kellgreen and Lawrence 1955, Body mass index (BMI) less than 40 kg / m², volunteers should have had knee pain for at least six months. All are from the Rehabilitation Sector of Santa Casa de Misericórdia de São Paulo (ISCMSP). The subjects were evaluated through a questionnaire developed by the authors of the study (Annex I), the Visual Analogue Scale (EVA) (Annex II), then applied to the Lower Extremity Functional Scale LEFS (Appendix III) and the Activities of daily living scale ADLs (Annex IV). In addition, the evaluation of muscular strength was through dynamometry using the Lafayete dynamometer model 01163, which was performed by a blind evaluator regarding the group that will belong to each candidate. The muscles tested were: quadriceps, ischiostibial and gluteus maximus. The randomization was through 60 brown envelopes divided into A, B, C and D, designating the randomness of the sample.

In addition to the initial evaluation, an evaluation was performed at the end of the tenth session and after 3 months of treatment.

The volunteers underwent a five-week treatment program, totaling 10 sessions, divided into four groups, group A - Intervention (INT) underwent knee and hip muscle strengthening exercises and electromagnetic field therapy with (Meditea - ARG) using the coplanar technique, group B - Exercises (EXE) carried out exercises to strengthen the hip and knee muscles in the C - Placebo group (PLA). hip and knee and electromagnetic field therapy with the Magnetron® coplanar technique, but with the device switched off and group D - Apparatus (APA) only use electromagnetic field therapy with the magnetron® coplanar technique. In the present study, there were no significant differences between groups regarding pain, function and muscle strength. However, group A obtained better results in the evaluated criteria, tending that the combination PEMF and exercises, is an indicated treatment for OA knee.

Inclusion Criteria:

• diagnosis of knee OA grade II and III
• Body mass index (BMI) of less than 40 kg / m²
• knee pain for at least six months

Exclusion Criteria:

• Severe OA above grade 3
• previous physical therapy for at least 6 months,
• any other affection of the lower limbs (LLL) and lumbar spine,
• obesity (BMI> 40),
• patients with cardiovascular, metabolic, neurological, oncological or history of knee surgery.