Inclusion Criteria:  Healthy volunteers Ability to perform all clinical tests and understand the study process, as well as obtaining informed consent. Tolerance to the application of electrotherapy. That they have not diagnosed any pathology. They do not present a contraindication to puncture and / or the application of electric currents.  Exclusion Criteria:  Neuromuscular disease. Epilepsy. Trauma, surgery or pain affecting the upper limb Osteosynthesis material in the upper limb. Diabetes. Cancer. Cardiovascular disease. Pacemaker or other implanted electrical device. Take any drug (NSAIDs, corticosteroids, antidepressants, analgesics, antiepileptics, ...) during the study and in the previous 7 days. Presence of tattoos or other external agent introduced into the treatment or assessment area. Pregnancy