02483nas a2200265   4500008004100000245008700041210006900128260000900197520162200206653001701828653002001845653002101865653002201886653002101908653001301929653001301942100002101955700002501976700001902001700001802020700002002038700001902058700002602077856011402103       2022                        eng d00aImpact of Gravity Compensation on Upper Extremity Movements in Harmony Exoskeleton0 aImpact of Gravity Compensation on Upper Extremity Movements in H  cJuly3 a<p>Robots have been used to offset the limb weight through gravity compensation in upper body rehabilitation to delineate the effects of loss of strength and loss of dexterity, which are two common forms of post-stroke impairments. In this paper, we explored the impact of this anti-gravity support on the quality of movement during reaching and coordinated arm movements in a pilot study with two participants with chronic stroke. The subjects donned the Harmony exoskeleton which supported proper shoulder coordination in addition to providing gravity compensation. Participants had previously taken part in seven one-hour sessions with the Harmony exoskeleton, performing six sets of passive-stretching and active exercises. Pre- and post-training sessions included assessments of two separate tasks, planar reaching and a set of six coordinated arm movements, in two conditions, outside of and supported by the exoskeleton. The movements were recorded using an optical motion capture system and analyzed using spectral arc length (SPARC) and straight line deviation to quantify movement smoothness and quality. We observed that gravity compensation resulted in an increased smoothness for the subject with high level of impairment whereas compensation resulted in a reduction in smoothness for the subject with low level of impairment in the reaching task. Both participants demonstrated better coordination of the shoulder-arm joint with gravity compensation. This result motivates further studies into the role of gravity compensation during coordinated movement training and rehabilitation interventions.</p>
10aExoskeletons10aNeural pathways10aOptical feedback10aOptical recording10aRobot kinematics10aShoulder10aTraining1 aHailey, Rhet, O.1 aDe Oliveira, Ana, C.1 aGhonasgi, Keya1 aWhitford, Bob1 aLee, Robert, K.1 aRose, Chad, G.1 aDeshpande, Ashish, D.  uhttps://reneu.robotics.utexas.edu/impact-gravity-compensation-upper-extremity-movements-harmony-exoskeleton-0