Integrated Approaches to Understanding and Improving Arm Function Post-Stroke

Abstract

This dissertation aimed to understand mechanics of upper extremity movements in daily activities and proposed new strategies to enhance arm function of stroke patients. Stroke often leads to severe long-term disability of upper extremity, which can impede the function of the arm and, as a result, restrict the independence of the patient. This research evaluated the functional importance of the degrees of freedom of upper extremity during functional daily tasks. Based on this understanding, two new rehabilitative approaches were proposed to enhance the motor recovery of stroke survivors. The first study aimed to understand joint coordination patterns of the upper extremity during functional tasks, and to quantify the range of motion of all upper extremity degrees of freedom (DOF). This investigation is crucial to understanding the relationship between distal and proximal joint coordination of the arm, as it facilitates the development of targeted interventions to restore the natural joint synergy. Findings revealed that variations in object shapes and locations can alter joint behaviors among individuals during a basic reaching task. The second study presented a passive arm device that provides targeted assistance to five DOF of shoulder and elbow joints. Each movement can be assisted by elastic bands that offer a personalized adjustable force. The third study examined a new virtual reality (VR) training program designed to encourage stroke patients to utilize their affected arm. The VR environment comprises four games that simulate daily tasks, allowing patients to engage with these activities while visually enhancing their impaired arm. The compliant group showed improvement in their arm function despite not proving real physical assistance. This VR game can serve as a future tool to address learned nonuse, a challenging behavioral issue frequently overlooked in stroke rehabilitation. These studies collectively offer a comprehensive framework to develop a novel methodology to improve arm function of chronic stroke survivors. The results will lead to the creation of personalized rehabilitation strategies that facilitate motor learning and ultimately enhance the quality of life for stroke survivors. This study establishes a basis for future progress in rehabilitation technology, promoting adaptive, patient-centered solutions that can be customized to the distinct motor requirements of each individual.