Physiological Complexity of Gait Over the First Six Months Post Stroke

Physiological complexity of gait, a measure of the interaction of multiple control mechanisms for walking within a biological system, is decreased in persons with chronic stroke compared to those without disability. Thus, it is assumed that the quantification of gait complexity represents the adaptability and health of the individual. However, it is unknown if the level of gait-related complexity improves over time with recovery from stroke. Therefore, the primary purpose of this study is to determine if the physiological complexity of gait changes over the first six months post stroke within the contemporary healthcare environment. Secondary aims include 1) determining if there is a difference between the amount of physiological complexity of gait and lateralization of hemispheric damage after stroke and 2) exploring the relationship of complexity to lower extremity motor impairment, walking speed and balance. Sixty individuals within one month post stroke from the greater Indianapolis area will be recruited for this prospective, longitudinal outcomes study. Testing sessions will occur at intervals across the first six months post stroke: within 1 month, at 3 months, and at 6 months post stroke. During each testing session, participants will complete a 2-minute walking task during which accelerometer signals from wireless inertial measurement units will be collected and converted to sample entropy to quantify the physiological complexity of gait. Additionally, measures to quantify lower extremity motor impairment, walking speed and balance will be collected and analyzed. Changes in complexity of gait from early to later stages of stroke recovery may serve as a foundation for prognosticating outcomes, such as predicting capacity for community mobility and/or risk of fall. The proposed study will meet a critical need to develop methods that differentiate among capacities for adapting movement patterns in individuals with neurological dysfunction. This work will ultimately build upon evidence that will assist therapists in tailoring interventions in such a way to optimize function.