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.