Inclusion Criteria:  18 years and < 70 years of age Height between 1.50 m and 1.95 m Weight between 45 kg and 110 kg Abdominal perimeter < 125 cm Written informed consent Affiliate or beneficiary of a social security scheme Able to comply with all protocol requirements  Confirmed diagnosis of a pathology belonging to one of the following family*:  Primary disorders of muscles  Muscular dystrophy Congenital myopathies Idiopathic inflammatory myopathy Mitochondrial myopathies  Metabolic disorders  Inborn errors of metabolism Glycogen storage disease  Functional capacities:  Able to stand up from a chair with armrest without other supports at least 3 times and at most 15 times in 30 seconds. Report the ability to walk without the assistance of a person at least 2min The use of traditional orthoses and walking aids will be accepted excepted knee orthoses and walkers (e.g. canes/crutches, ankle foot orthosis).  Exclusion Criteria:  Unable to participate in the study Inability to comply with protocol requirements Guardianship/trusteeship Pregnant or nursing women Unstable Cardiomyopathy Symptomatic orthostatic hypotension Medical history of osteoporotic fracture Balance disorder with extra neuromuscular causes Recent trauma (fall, accident, ...) Unstable Cardiomyopathy Severe respiratory insufficiency Flexion contracture in the knee and hip joint in excess of 10° Varus malposition in excess of 10° or valgus malposition in excess of 10°