Notice and Invitation Oral Defense of Doctoral Dissertation Bioengineering Department College of Engineering and Computing, George Mason University Syeda Khadija Fatima Zaidi Bachelor of Science, Bioengineering, University of Maryland, College Park, May 2012 Multi-scale Representations of Functional Movement - Quantitative Analysis of Upper Extremity Movement Severity and Dissimilarity after Stroke Thursday, Nov. 16, 2023, 1:00 pm - 3:00 pm Peterson 2000 In-person preferred. Zoom<https://gmu.zoom.us/j/94427544673?pwd=ZTl0QnF2dll5SjVjQnhUelBsZUFNdz09> if needed. Meeting ID: 944 2754 4673 Passcode: 241981 All are invited to attend. Committee Dr. Qi Wei, Director Dr. Siddhartha Sikdar, Chair Dr. Shani Ross Dr. Kathryn Laskey Abstract The upper extremity is a highly motor-abundant, non-linear, and non-periodic system of muscles and joints, with the ability to produce a vast variety of movements. From reaching for a toothbrush in the morning to pulling up the covers at night, our arms and hands are a significant part of how we interact with the world. Central Nervous System (CNS) injuries such as lesions consequent to stroke are a leading cause of disability, often accompanied by hemiparetic impairment and functional limitations in the ability to reach to grasp, transport, and release objects. Upper extremity impairment severity differs vastly from person to person, persistently affecting about 80% of persons six months past the stroke event. Without a model for translating movement capacities into individualized therapies, rehabilitative interventions are at best estimations of how the underlying neural structures will respond and produce movement. There is currently no consensus on which movements best represent the motor capacities of the upper extremity, and which kinematic metrics contribute to a comprehensive standardized representation of the multi-joint upper limb. A quantitative and universal summary index of upper extremity multi-joint movement would be a valuable tool for assessing limb coordination, compensatory maladaptations, and recovery. This dissertation describes the use of reaching as a representative functional task to develop an objective score of upper extremity motor performance. The Reach Severity and Dissimilarity Index was developed with novel data segmentation strategies, designed to identify preserved movement behaviors and be sensitive to stroke-related and age-related differences in bilateral coordination.