Osteoarthritis (OA) is the most common joint disease. It is characterized by a progressive destruction of all the components of the joint, especially the cartilage. This leads to pain, loss of mobility and can be a major handicap for some patients. Gonarthrosis, or osteoarthritis of the knee, affects 30% of people between the ages of 65 and 75 and is one of the most disabling conditions. In the final stage, the only therapeutic option to relieve patients is to replace the joint with a total knee prosthesis. Thanks to the contribution of an evaluation technique based on inertial sensors (X-SENS device), our objective is to better evaluate and understand the movement deficit in knee OA subjects. The hypothesis is that, thanks to the contribution of a technique based on inertial sensors (X-SENS), the investigators can better evaluate the movement deficit of knee OA subjects. The goal is to propose specific, rapid telekinetic biomarkers, allowing a better evaluation of functional improvements following therapeutic interventions, such as a total knee replacement.