Inclusion Criteria:  Patients, 18 years and older, undergoing regional anesthesia with a peripheral nerve block allowing a neurostimulation.  Exclusion Criteria:  Contraindications to a peripheral nerve block Risk of severe intoxication to local anesthesia Peripheral nerve block in an area not allowing neurostimulation due to absence of motor fibers (for example, adductor canal block) Patient refusal Patient unable to communicate with the health or research team