Skill generalization relevant to robotic neuro-rehabilitation.

Upper limb extremity rehabilitation practices are increasingly involving robotic interaction for repetitive practice, and there is increasing skepticism whether such systems can provide the relevant practice that can be generalized (or transferred) to functional activities in the real world. Most importantly, will patients be able to generalize in three critical ways: (1) to unpracticed directions, (2) to unpracticed movement distances, and (3) to unpracticed weight-eliminated conditions? Rather than presuming that patients could generalize in three conditions, this study tested whether there was any evidence of such generalization ability in healthy individuals. We found that there was some evidence in all conditions except for the ability of healthy subjects to generalize to large movements after practicing small. Such results suggest that larger robotic systems are advantageous for training the functional motions that can include large actions.