Preliminary design of an exoskeleton shoulder joint without dead positions

The effect of a twist dimension on the dexterity of double pointing systems is studied. It is found that as the twist increases from 0° the dexterity of the double pointing system is continually reduced. However a twist dimension of up to 81° allows for a dexterous exoskeleton shoulder joint workspace large enough to accommodate the range of shoulder joint motion in the typical human. This amount of twist greatly simplifies the design of the shoulder joint exoskeleton, allowing room for hardware such as gearing