The MEOPA is used to obtain an analgesia of the short-term painful acts. To the population of elderly patients, the therapeutic resources to control the passing pain require in their manipulation a certain caution and are not divested of side effects badly tolerated at this age. An alternative in the opioid presents all its interest. The MEOPA is here an alternative of choice in the care of these pains, in particular in case of pre-existent cognitive achievement, of polypathologies or of polymédication.

The gas MEOPA administered to the mask could thus be an effective additive in the physiotherapy treatment of the elderly person.

The main objective is to Assess the efficacy , in terms of recovery of the hip and knee joint articular amplitude, of 3 sessions of reeducation using MEOPA versus standard reeducation within a population of elderly patients presenting a pain during the physiotherapy treatment.

Inclusion Criteria:

• Male or female aged 65 years old or more
• Patients having a prescription for physiotherapy
• Absence of contraindication to MEOPA
• Patients whose initial assessment show a passive articular deficit of at least a joint of hip or the knee and whose painful assessment is ≥ 5 or ≥ 2 during mobilisation on the validated scale Algoplus
• Patients whose reeducation project established by the physiotherapist
• Patients having agreed to participate in the study and having signed the consent
• Subjects affiliated to the social security system

Exclusion Criteria:

• Patient requiring a ventilation in pure oxygen
• Patient with a consciousness deterioration preventing his cooperation
• Care under MEOPA during the period of the protocol and during the month which precedes
• Increase of the dosage of morphine of less than 48 hours Patient under guardianship