Inclusion Criteria:  Patient having signed a free and informed consent Being affiliated or benefiting from a social security system Having dual mobility cup for at least 1 year Outside of a period of exclusion from the national file of persons undergoing biomedical research Age greater than or equal to 50 years Of a cognitive level compatible with oral communication, the respect of instructions and the understanding of the gestures carried out  Exclusion Criteria:  Persons who are not physically able to perform tests Persons currently participating in another research project with an exclusion period Persons of full age under legal protection or unable to express their consent Pregnant or breast-feeding women (Article L1121-5 of the Public Health Code (CSP)) Persons deprived of their liberty by a judicial or administrative decision, persons under psychiatric care and persons admitted to a health or social institution for purposes other than research