Knee osteoarthritis (O.A. from now on) is associated to muscular weakness of inferior limbs, especially the quadriceps; leading to disease progression. Advantages of muscular strength training for the treatment of this kind of O.A. is now well established. In this therapeutic field, isokinetic exercises seem to have a better efficiency than other, more frequently used, kinds of exercises such as isometric or isotonic exercises.

Functional impairment caused by knee O.A. is mainly affecting walking. Walking induces muscles to work in eccentric mode.

The hypothesis of this study is that muscular strengthening using isokinetic exercises in eccentric mode would have a more important benefit than isokinetic exercises in concentric mode. Such an hypothesis, if verified, could lead to a better management of rehabilitative knee exercises in the treatment of knee O.A.

Knee osteoarthritis (O.A. from now on) is associated to muscular weakness of inferior limbs, especially the quadriceps; leading to disease progression. Advantages of muscular strength training for the treatment of this kind of O.A. is now well established. In this therapeutic field, isokinetic exercises seem to have a better efficiency than other, more frequently used, kinds of exercises such as isometric or isotonic exercises.

Functional impairment caused by knee O.A. is mainly affecting walking. Walking induces muscles to work in eccentric mode.

The hypothesis of this study is that muscular strengthening using isokinetic exercises in eccentric mode would have a more important benefit than isokinetic exercises in concentric mode. Such an hypothesis, if verified, could lead to a better management of rehabilitative knee exercises in the treatment of knee O.A.

Inclusion Criteria:

• Patient male or female, age ranging from 40 to 70 years old
• Patient suffering from one-sided knee O.A. regarding criteria of the American College of Rheumatology (A.C.R.), with radiologic score ranging from 2 to 3 according to the Kellgren & Lawrence classification.
• Patient receiving medical support
• Patient that did not receive any infiltration on knee within two months before randomisation.
• Patient free from any disease that could be a contraindication to the study treatment
• Patient able to understand the protocol and willing to comply with its rules.
• Patient willing to give consent.
• Patient affiliated to the french social secu

Exclusion Criteria:

• Patient carrying prosthesis.
• Patient suffering from inflammatory arthritis, or flare of arthritis.
• Patient suffering from symptomatic patellofemoral osteoarthritis.
• Patient suffering from cardio-vascular or pneumologic disease that could a contraindication to the study treatment.
• Patient suffering from any pathology that could cause muscular weakness (myopathy, neuropathy, hemiplegia...)