Reed Handlery

Date of Award

Fall 2020

Document Type

Open Access Dissertation

Department

Exercise Science

First Advisor

Stacy Fritz

Abstract

Despite the well-known health benefits associated with physical activity (PA), the majority of people with Parkinson’s disease (pwPD) and people with stroke do not meet national PA guidelines. As a result, these two groups of people are at increased risk for development of cardiovascular disease, additional disability and death.

Walking as a mode of PA has been shown to improve the health of both pwPD and people with stroke. In fact, a step count of >6000 steps per day is related to a decreased risk of subsequent cardiovascular events in people with stroke. Daily walking is also strongly recommended by the U.S. surgeon general and national PA guidelines. Currently, however, guidelines do not recommend a specific daily step count for pwPD or stroke and the relationship between daily steps and health in these individuals is unclear.

The overall purpose of the following two studies was to identify daily step counts associated with health outcomes in pwPD and people with stroke. Specifically for pwPD (Chapter 2), the purpose was to 1) determine a step threshold that corresponds to meeting aerobic PA guidelines, 2) determine effects of treadmill exercise performed at varying intensities on PA and 3) quantify the relationship between changes in daily steps and fitness. For people with stroke (Chapter 3) the purpose was to 1) determine which factors at two months post-stroke can predict daily step counts at one year, and 2) determine what step count at two months corresponds to obtaining >6000 daily steps at one year post-stroke.

Data for both studies were obtained from publicly available datasets. The first study included 110 individuals with de novo Parkinson’s disease who were allocated to one of three groups (high-intensity treadmill exercise, moderate-intensity treadmill exercise or control) for six months. Baseline step data and Receiver Operating Characteristic (ROC) curves were used to determine which step count corresponded to meeting PA guidelines. The effect of treadmill exercise on PA was examined in those below the step threshold (i.e. the least active participants). Pearson’s r correlations determined the relationship between daily steps and fitness. The second study included 206 participants with stroke who were allocated to one of three groups (36 sessions of body weight–supported treadmill training at two months post-stroke, 36 sessions of body weight–supported treadmill training at six months post-stroke, or 36 sessions of progressive supervised home exercise program). Daily steps were assessed at two months and one year post-stroke. Linear regression was used to predict daily step counts at one year based on factors including age, gender, race and/or ethnicity, stroke severity, walking speed and endurance, fitness, motor function, balance and balance confidence. A Receiver Operating Characteristic (ROC) curve determined which step count corresponded to reaching >6000 steps at one year.

Results indicate that for pwPD, a daily step count of >4200 corresponds to meeting PA guidelines. For participants with <4200 daily steps at baseline, high-intensity treadmill exercise led to improvements in daily steps but these changes were not associated with changes in fitness. Overall, pwPD should be encouraged to take >4200 daily steps in order to meet PA guidelines through walking. For people with stroke, daily steps and balance at two months post-stroke were the strongest predictors of future daily steps. Thus, improving daily PA and balance early after stroke may be necessary to increase PA levels at one year post-stroke. A step count of >1632 steps per day at two months post-stroke corresponded to obtaining >6000 daily steps at one year.

Rights

© 2020, Reed Handlery

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