Neurological deficits after cerebrovascular accidents very frequently disrupt the
kinematics of voluntary movements with the consequent impact in daily life activities.
Robotic methodologies enable the quantitative characterization of specific control
deficits needed to understand the basis of functional impairments and to design effective
rehabilitation therapies. In a group of right handed chronic stroke survivors (SS)
with right side hemiparesis, intact proprioception, and differing levels of motor
impairment, we used a robotic manipulandum to study right arm function during discrete
point-to-point reaching movements and reciprocal out-and-back movements to visual
targets. We compared these movements with those of neurologically intact individuals
(NI). We analyzed the presence of secondary submovements in the initial (i.e. outward)
trajectory portion of the two tasks and found that the SS with severe impairment (FM
< 30) presented arm submovements that differed notably not only from NI but also from
those of SS with moderate arm impairment (FM 30-50). Therefore the results of this
pilot study suggest that in SS arm kinematics vary significantly across differing
levels of motor impairment. Our results support the development of rehabilitation
therapies carefully tailored to each individual stroke survivor.