Much of his research involved the study of the internal representation of the body and external space in the human brain, to understand how the brain forms the models on the basis of which motor behavior is realized. His concept of the role of the "body schema" in generating the physical confi- gurations of the body for action, in an anticipatory process, was a key concept not only for modern physiology but also for a completely novel approach tomany pathologies. His main scientific interest was the control of posture and movement in humans. He was a pioneer in the use of stabilography for the study of human upright posture. He had a particular interest in the normal regulation of and disturbances to muscle tone and how these disturbances affect movement performance. He was also interested in the biophysical mechanisms of skeletal muscle con- traction. His studies of postural regulation led him to conclude that themotor system is not reduced to a set of simple postural reflexes. He was also involved in thedevelopment of the principles of adaptive control of robots and manipulators, the development of modular torque sensors and other de- vices for processing this sensor information in robots, in particular, for an ambulating six-legged walking device. He contributed to several space flights in the MIR station with the French CNES.