Therapeutic role of motor imagery at six month following total knee arthroplasty

All participants will undergo the same physiotherapy treatment with the same physiotherapist. They will receive 12 individual sessions of physiotherapy of 1 hour each, scheduled 3 times per week. Treatment will begin 6 months post-operatively. In the experimental group, we will add “motor imagery” exercises into classical physiotherapy session during the last 15 minutes of the session. Practically they will practice a sequence of motor imagery exercises (kinesthetic and visual imagery). The control group will be subjected to a period of neutral activities during equivalent time. Accordingly they will spend the last 15 minutes of the session to discuss with the physiotherapist of world news not related to their illness. the 45 minutes of classical physiotherapy included: quadriceps strengthening exercises, proprioceptive exercises and gait training exercises (maximum knee flexion during swing phase). Motor imagery is defined as the mental representation of an action without any concomitant movement. During each motor imagery session, we used visual imagery that requires self-visualization of a movement from a first- (internal visual imagery) or third-person (external visual imagery) perspective and kinesthetic imagery that requires to feel movement and to perceive muscle contractions mentally.Participants performed 2 blocks of each set with a 10-s rest period between rehearsals and 2-min rest period between blocks. The physiotherapist checked whether the participants did not contract their muscles or move their knees during motor imagery exercises. All exercises should be showed firstly by the experimenter and secondly the participants should do one trial with the contra lateral limb before starting with the operated limb. During motor imagery training, the physiotherapist read the same imagery script specific for each exercise to ensure that the participants received similar motor imagery instructions. An informed consent including the description and the schedule of the rehabilitation program will be signed by all participants. Furthermore all participants will provide a signature at the end of every session.