Inclusion Criteria:  Affiliates or beneficiaries of a social security scheme Having freely given their written consent  Exclusion Criteria:  Disease or surgery resulting in a locomotor disorder, within 6 months prior to the study Chronic neurological, motor or psychic diseases Taking neuro-active substances likely to alter cortico-spinal excitability (hypnotics, antiepileptics, psychotropic drugs, muscle relaxants) for the duration of the study Contraindication to neuromuscular electrostimulation Contraindication to magnetic stimulation Participation at the same time in another interventional experiment or having participated in such a study within 30 days prior to this study Sports (>10 hours per week or strength training of the lower limbs)