Evaluation of Locomotor Activity Before and After Total Hip Replacement in Patients With Hip Osteoarthritis.

Inclusion Criteria: Control group: * Subjects who have provided written informed consent * Subjects covered by the national health insurance scheme * Men or women aged between 25 and 85 years * able to understand simple instructions and packaging instructions and able to give informed consent Patients group: * Patients who have provided written informed consent * Patients covered by the national health insurance scheme * Men or women aged between 25 and 85 years * able to understand simple instructions and packaging instructions and to give their informed consent * Suffering from hip osteoarthritis defined according to ACR criteria * Most recent radiography examination less than 6 months earlier * Radiological stage II, III or IV hip osteoarthritis according to the Kellgren and Lawrence classification * Presenting with an indication for total hip replacement, according to the surgeon's usual criteria Exclusion Criteria: Control group: * Hip osteoarthritis or other arthrosis in the lower limbs * Pregnant or breast-feeding women * Disorders that may interfere with gait analysis * Disorder that may be destabilized by gait analysis * Neurological disease and/or motor neuron disease Patients group: * Contra-indication for total hip replacement * Repeat surgery for total hip replacement * Impossibility to use a standard implant * Pregnant or breast-feeding women * Inflammatory flare of the hip osteoarthritis * Disorder that may interfere with gait analysis * Disorder that may be destabilized by gait analysis * Rapidly destructive hip osteoarthritis * Neurological disease and/or motor neuron disease * Hip dysplasia requiring THR to be completed using a graft