Neural Stimulation for Hand Grasp

A selective neural stimulation as the investigators propose allows to stimulate several muscles via a single electrode. Neural stimulation requires less energy for muscle activation. In our approach, 2 electrodes will be implanted above the elbow on the median and radial nerves. This considerably reduces the number of implanted elements and therefore i) the risk of infection, ii) the risk of failure, iii) the surgical risk through minimally invasive surgery. Our main hypothesis is that multipolar neural electrical stimulation of the median nerve (flexion) and the radial nerve (extension) allows: * on the one hand, a selective, individualized motor activation (muscle by muscle) * on the other hand, a synergistic motor activation (association of several muscles) for the purpose of production of functional movements.