title: Robotic therapy for chronic stroke: general recovery of impairment or improved task-specific skill?
abstract: There is a great need to develop new approaches for rehabilitation of the upper limb after stroke. Robotic therapy is a promising form of neurorehabilitation that can be delivered in higher doses than conventional therapy. Here we sought to determine whether the reported effects of robotic therapy, which have been based on clinical measures of impairment and function, are accompanied by improved motor control. Patients with chronic hemiparesis were trained for 3 wk, 3 days a week, with titrated assistive robotic therapy in two and three dimensions. Motor control improvements (i.e., skill) in both arms were assessed with a separate untrained visually guided reaching task. We devised a novel PCA-based analysis of arm trajectories that is sensitive to changes in the quality of entire movement trajectories without needing to prespecify particular kinematic features. Robotic therapy led to skill improvements in the contralesional arm. These changes were not accompanied by changes in clinical measures of impairment or function. There are two possible interpretations of these results. One is that robotic therapy only leads to small task-specific improvements in motor control via normal skill-learning mechanisms. The other is that kinematic assays are more sensitive than clinical measures to a small general improvement in motor control.
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York; tk2229@columbia.edu.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kitago
authors.affiliation: Department of Biostatistics, Mailman School of Public Health, New York, New York;
authors.forename: Jeff
authors.initials: J
authors.lastname: Goldsmith
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York;
authors.forename: Michelle
authors.initials: M
authors.lastname: Harran
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York;
authors.forename: Leslie
authors.initials: L
authors.lastname: Kane
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York;
authors.forename: Jessica
authors.initials: J
authors.lastname: Berard
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York;
authors.forename: Sylvia
authors.initials: S
authors.lastname: Huang
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York; Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts;
authors.forename: Sophia L
authors.initials: SL
authors.lastname: Ryan
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York;
authors.forename: Pietro
authors.initials: P
authors.lastname: Mazzoni
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York; Departments of Neurology and Neuroscience, Johns Hopkins University, Baltimore, Maryland.
authors.forename: John W
authors.initials: JW
authors.lastname: Krakauer
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York;
authors.forename: Vincent S
authors.initials: VS
authors.lastname: Huang
mesh_terms: D000368:Aged; D001132:Arm / Q000502:physiology; D001696:Biomechanical Phenomena; D002545:Brain Ischemia / Q000503:physiopathology* / Q000534:rehabilitation; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D020127:Recovery of Function; D012371:Robotics; D020521:Stroke / Q000503:physiopathology*; D000071939:Stroke Rehabilitation
keywords: kinematics; motor control; neurorehabilitation; robotic therapy; stroke