Identifying the role of proprioception in upper-limb prosthesis control

Proprioception plays a crucial role in enabling humans to move purposively and interact with their physical surroundings. Current technology in upper-limb prostheses, while beginning to incorporate some haptic feedback, does not provide amputees with proprioceptive information about the state of the limb. Thus, the wearer must visually monitor the limb, which is often inconvenient or even impossible for some tasks. This work seeks to quantify the potential benefits of incorporating proprioceptive motion feedback into upper-limb prosthesis designs. We apply a noninvasive method for controlling the availability of proprioceptive motion feedback in unimpaired individuals in a human subject study to compare the benefits of visual and proprioceptive motion feedback in targeted motion tasks. Combined results of the current study and our previous study using a different task indicate that the addition of proprioceptive motion feedback improves targeting accuracy under nonsighted conditions and, for some tasks, under sighted conditions as well. This work motivates the development of methods for providing artificial proprioceptive feedback to a prosthesis wearer.