Grand Rounds Seminar

Abstract: Upper extremity (UE) motor impairment affects 50–80% of stroke survivors in the acute phase and persists in up to 50% at six months. Despite this high burden, individuals with chronic moderate-to-severe chronic impairment, who often lack sufficient hand function for daily activities, remain markedly underrepresented in clinical research. Consequently, this population has the greatest functional need but the least empirical guidance for recovery. To address this gap, we developed the ReIn-Hand system, a customized forearm/hand orthosis that integrates electromyography (EMG)-driven functional electrical stimulation (FES). The system decodes EMG signals during volitional use of the whole UE; upon detecting the intent to open the hand, the platform triggers FES to facilitate the movement. Over the past seven years, we conducted a double-blinded, randomized controlled trial. Fifty-three adults with chronic stroke (mean time post-stroke = 7.4 years) were randomized into two groups. Both groups completed 24 sessions over 8 weeks of intensive practice with the ReIn-Hand device. The experimental group received additional robotic shoulder support via the PACT3D robot, while the control group utilized the ReIn-Hand device alone. Participants across both groups demonstrated steady improvements in object manipulation, with approximately 40% reaching "clinically meaningful" milestones. Overall gains were observed in arm function, hand function, and sensory perception (touch and proprioception). Multimodal imaging (EEG and DTI) revealed that recovery in these survivors is driven by a combination of compensatory and restorative mechanisms. This is primarily characterized by volume increases in the corpus callosum, supporting robust, bidirectional, cross-frequency communication for improved UE control.  

About: Dr. Yao is a Professor within the Department of Physical Therapy & Human Movement Sciences, as well as McCormick School of Engineering. She is interested in using multi-modality brain imaging and signal processing methods to explore the neuromechanisms underlying movement disorder following injuries to the nervous system. By combining neuro-scientific understandings with advanced biomedical engineering techniques, such as neural machine interface, she developing new rehabilitation methods to regain the functional control of the impaired hand in moderately to severely impaired stroke survivors.

March 25, 2026: Jun Yao, PhD
Professor, Physical Therapy and Human Movement Sciences
Professor, McCormick School of Engineering
Northwestern University

May 13, 2026: John R. McGuire, MD
Physical Medicine and Rehabilitation
Froedtert & the Medical College of Wisconsin
Northwestern University