Many robotic devices in rehabilitation incorporate an assist-as-needed haptic guidance paradigm to promote training. This error reduction model, while beneficial for skill acquisition, could be detrimental for long-term retention. Error augmentation (EA) models have been explored as alternatives. A robotic Tethered Pelvic Assist Device has been developed to study force application to the pelvis on gait and was used here to induce weight shift onto the paretic (error reduction) or nonparetic (error augmentation) limb during treadmill training. The purpose of these case reports is to examine effects of training with these two paradigms to reduce load force asymmetry during gait in two individuals after stroke (>6 mos). Participants presented with baseline gait asymmetry, although independent community ambulators. Participants underwent 1-hr trainings for 3 days using either the error reduction or error augmentation model. Outcomes included the Borg rating of perceived exertion scale for treatment tolerance and measures of force and stance symmetry. Both participants tolerated training. Force symmetry (measured on treadmill) improved from pretraining to posttraining (36.58% and 14.64% gains), however, with limited transfer to overground gait measures (stance symmetry gains of 9.74% and 16.21%). Training with the Tethered Pelvic Assist Device device proved feasible to improve force symmetry on the treadmill irrespective of training model. Future work should consider methods to increase transfer to overground gait.
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From the Department of Rehabilitation and Regenerative Medicine, Columbia University Medical Center, New York, New York (LB, LQ, JS, SA); Department of Biobehavioral Sciences, Programs in Movement Science & Kinesiology, Teachers College, Columbia University, New York, New York (LB, LQ); Department of Mechanical Engineering, Robotics and Rehabilitation Lab, Fu Foundation School of Engineering and Applied Science, Columbia University, New York, New York (MK, DM, SA); and Department of Rehabilitation Medicine, Weill Cornell Medical College, New York, New York (JS).
All correspondence and requests for reprints should be addressed to: Lauri Bishop, PT, DPT, Department of Rehabilitation & Regenerative Medicine, Columbia University Medical Center, 180 Fort Washington Ave., Suite 199, New York, NY 10032.
Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article.
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