Today, if surgery is not an option, functional electrical stimulation (FES) is the only possibility for partially restoring lost motor functions (Hentz and Le Clercq, 2002). In this context, the term neuroprostheses is used to describe FES systems aiming at the restoration of a weak or lost grasping function of the hand. Some of these neuroprostheses are based on surface electrodes for external stimulation of muscles of the hand and forearm. Examples are the commercially available NESS-H200 System (Bioness Inc., Valencia, USA) (Ijzermann et al., 1996) and other more sophisticated research prototypes (Thorsen et al., 2001; Mangold et al., 2005). The Freehand system (NeuroControl, Cleveland, USA), an implantable neuroprostheses, overcomes the limitations of surface stimulation electrodes concerning selectivity and reproducibility (Keith and Hoyen, 2002). All FES systems for grasp restoration have in common the fact that they can only be used by patients with preserved voluntary shoulder and elbow function, which is the case in patients with an injury of the spinal cord below C5. Only two groups have dealt with the problem of restitution of elbow and shoulder movement. Memberg et al. (2003) used an extended Freehand system, while Handa's group (Kameyama et al., 1999) developed a system based on intramuscular electrodes. Both systems represent exclusive FES systems, which stimulate the appropriate muscle groups not only for dynamic movements but also for maintaining a static posture. Due to the weight of the upper limb and the non-physiologic synchronous activation of the paralyzed muscles through external electrical pulses, rapid muscle fatiguing occurs. An alternative is, as for the case of standing and walking neuroprosthesis, to use a combination of FES with a mechanical orthosis (Goldfarb and Durfee, 1996; Kobetic et al., 2003). A passive, but lockable orthosis stabilizes the knee joint during the stance phase without the need for a continuous co-contraction of antagonistic muscle groups. For the restoration of an elbow function much less torque has to be generated and held, thus supporting the idea that a passive, lockable orthosis combined with a FES-system will be successful in restoration of upper limb function. Up to now such a system does not exist.