Léonard FÉASSON is a University Professor - Hospital Practitioner in Physiology at Faculty of Medicine of J. Monnet University and at the CHU of St Etienne. In 1999, he created the Myology Unit of the Hospital Department of Clinical Physiology and Exercise. This Unit is located within the Regional Institute of Sports Medicine and Engineering (IRMIS), of which he is the medical manager. Clinical activities of specialized consultations in Myology, functional explorations through exercise, histopathology and biochemistry of skeletal muscle tissue are carried out there, within the framework of the Referent Center for Neuromuscular Diseases - Euro-NmD. He coordinates the multidisciplinary adult neuromuscular consultation in the Department of Neurology. His research activity is focused on understanding the mechanisms involved in the adaptation, maintenance or repair of skeletal muscle and its function, and the development of physical reconditioning strategies to limit their degradation, major social issues. In the Interuniversity Laboratory of Human Movement Biology (LIBM-EA7424), his approach is multidisciplinary and translational, based on histological, biochemical and molecular tissue techniques and integrative functional physiological analyzes applied to healthy or pathological human subjects. Thanks to numerous national and international collaborations, he has contributed more than a hundred journal articles and his H index is 34.