Janice Eng

Independent ambulation in the community is often stated as important amongst people post-stroke. Walking within the community can be complex, requiring speed changes during walking, attention or interaction with the environment and other people. After a stroke, the ability to complete these specific walking tasks is often impaired. Currently, determining appropriate gait rehabilitation interventions post-stroke is based on clinical observations such as motor, sensory, cognitive, and balance ability. These methods, however, may not be sensitive or objective enough to detect change or appropriateness for specific interventions. Assessment of individual functional brain activation is a promising method for determining appropriateness of gait rehabilitation interventions and can provide insight on resource allocation, neural efficiency, and neural compensations. This dissertation consists of four independent studies. The first is a review of the current findings of brain activation during walking post-stroke and identified the gaps within the literature. This review then informed the next three studies where functional near-infrared spectroscopy was used to assess real-time brain activation during different types of walking: normal-paced, slow, fast, and dual-task walking. Results from these studies show task- specific activation of brain regions across the frontal and parietal cortices as well as relationships between brain activation and clinical measures of impairment and performance. Notably, consistent increases in ipsilesional prefrontal cortex was observed with each walking task, premotor cortex was involved when walking was not at a normal-pace, and activation in sensorimotor and posterior parietal cortices related to gait speed. Results from these studies contribute basic scientific knowledge towards the neural correlates of walking after a stroke and can be an important reference for future interventions aimed to improve walking recovery.

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Stroke is a leading cause of disability worldwide. Upper limb impairments that lead to difficulties incorporating the arm into daily activities are particularly common. Facilitating upper limb recovery is an important and complex endeavor in stroke rehabilitation. Upper limb use in one’s own environment is a key marker of upper limb recovery and is a potential important target for treatment. Self-report measures of upper limb use and wearable sensors that provide interpretable feedback about upper limb activity may make an important contribution to our understanding and facilitation of upper limb recovery. This dissertation consists of four studies. The first study used screening data from a consecutive sample longitudinal study to explore an updated prevalence of early upper limb weakness after stroke. This study suggested that upper limb weakness prevalence may be lower in the post-reperfusion therapy era and provides information about the population who will likely have difficulties using their upper limb. The second study used a longitudinal design to explore the trajectory of upper limb use in the first-year post stroke. Information from this study may inform the timing of interventions aimed at increasing upper limb use and provides evidence supporting the responsiveness of a quick-to-administer self-report measure of use. The third study used a qualitative focus group design to explore clinicians’ perceptions of a wearable device that captures upper limb activity. This study found that clinicians’ support the development of these devices for use outside of therapy and highlighted some features that may increase their clinical uptake. The final study used a cross-sectional design to provide preliminary evidence that supports the ability of a new wearable device to capture functional hand activities after stroke. Together these studies advance our knowledge about an important aspect of upper limb recovery and informs the development of a clinical trial that uses feedback from a wearable device to facilitate greater upper limb use after stroke.

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Stroke is a leading cause of adult disability, typically resulting in mental and physical impairments that can affect functional abilities such as walking. Recovering the ability to walk is an important goal for stroke survivors, having implications for long-term health and functional outcomes. Population trends and new medical interventions have resulted in changes in mortality and disablement, warranting an update of the prevalence of leg and walking impairment after stroke; interventions to optimize walking recovery after stroke also remain a key priority for research. Powered robotic exoskeletons, a new generation of electromechanical devices that can support and move the lower limbs to walk overground, may be a novel intervention to achieve higher-intensity walking practice and rehabilitation gains for patients after stroke.The aims of this dissertation were to characterize the current state of leg and walking impairment after stroke, as well as to investigate the role of exoskeletons, both their efficacy and acceptability, in stroke rehabilitation. A cohort study first established that approximately half of patients surviving a first-ever stroke are unable to walk, affecting their discharge disposition after acute hospitalization. The second study, a scoping review, mapped the existing research surrounding the use of powered exoskeletons for overground gait retraining and highlighted a need for more rigorous trials in the subacute stroke population. The third and fourth studies were conducted concurrently as a mixed methods trial to investigate the use of powered exoskeletons for gait retraining with non-ambulatory patients during subacute stroke rehabilitation. In the randomized controlled trial, no greater benefit was achieved by using a powered exoskeleton for walking recovery compared to standard physical therapy care. However, the qualitative component, an interview-based study exploring how patients and therapists react to using an exoskeleton for intensive rehabilitation, revealed that the technology is viewed highly favorably. In summary, these studies, which focused on non-ambulatory patients, indicate an ongoing need to target walking recovery after stroke and suggest that powered exoskeletons are a welcome option to achieve repetitive walking practice. Further work is needed to clarify which patients will truly benefit, and to what extent, from this intervention.

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Background: Recurrent strokes, which may comprise up to a fifth of all stroke, are more severe than first events. Optimal secondary stroke prevention may require changes to health-related behaviours and improved vascular risk factor control. While patients’ knowledge regarding stroke, health-related behaviours, and cardiovascular risk may improve with secondary prevention strategies, there is little information available to guide programs for patient and family education for stroke prevention. Purpose: First, to assess the knowledge of individuals with a recent stroke about stroke symptoms, risk factors, and prevention. Second, to explore the association between stroke knowledge and health behaviours and cardiovascular risk factor control. Last, to explore perceived barriers and facilitators for participation in secondary prevention programs for stroke survivors and their caregivers, and to examine the effectiveness of nursing interventions on modification of stroke risk factors among stroke survivors. Methods: A prospective cross-sectional study was conducted to assess the knowledge of individuals with recent stroke and its relation to health-related behaviours and cardiovascular disease risk. Then, a longitudinal qualitative study was conducted using individual interviews with stroke survivors and their caregivers to understand changes in their perceptions regarding secondary stroke prevention in the stroke recovery period. Lastly, a meta-analysis of randomized controlled trials was conducted investigating the role of nurses in secondary stroke prevention. Results: The cross-sectional study revealed that stroke patients lacked knowledge about stroke, and those who had better stroke knowledge had better health-related behaviours. Those who were physically active prior to their stroke had better cardiovascular risk factor control. In the qualitative study, stroke was perceived as a soul-searching experience by stroke survivors and their caregivers, motivating them to consider its causes. Despite experiencing some barriers, stroke survivors made lifestyle adjustments, transitioning through different stages of change. The meta-analysis found that nursing interventions were associated with improvements in blood pressure control, diet, physical activity, medication adherence, and knowledge of stroke risk factors. Conclusions: The findings demonstrate the importance of strengthening current programs for secondary stroke prevention. Further, the findings suggest that developing patient- and family-centered programs may improve the knowledge and health-related behaviours to optimize secondary stroke prevention.

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Background: Stroke is a serious health concern and a leading cause of disability worldwide. Up to two-thirds of stroke survivors will experience physical and/or cognitive deficits thus requiring ongoing rehabilitation. Determining the appropriate exercise intensity and dose to optimize recovery is one of the top priorities in stroke rehabilitation research.Purpose: To determine the feasibility and efficacy of higher exercise intensity and dose on walking and functional recovery, cognition, and quality of life in the early phase after stroke.Methods: Multiple studies were conducted to examine how exercise intensity and dose may influence recovery early after stroke. Two studies were completed to identify and assess the precision of a readily available monitoring device to accurately record step count, a measure of walking dose. The results of these studies contributed to the design and implementation of an ongoing national, multi-site, randomized clinical trial occurring during inpatient stroke rehabilitation, to investigate how higher exercise intensity and dose impact walking and functional recovery, cognition, and quality of life. Results: From the two studies examining measurement of walking dose, The Fitbit One was identified as a monitoring device that could accurately assess step count ( 10% error), when positioned at the ankle, with individuals post-stroke that had a walking speed greater than 0.4m/s. Preliminary data from the ongoing multi-site randomized clinical trial revealed that individuals who received a higher exercise intensity and dose within their inpatient stroke rehabilitation were able to walk a clinically meaningful longer distance on the six-minute walk test and had a higher perception of their health status compared to those individuals that received usual care physical therapy.Conclusions: Higher exercise intensity and dose can be accurately measured and safely delivered during inpatient stroke rehabilitation. Furthermore, although preliminary results suggest that higher exercise intensity and dose may be effective at improving walking recovery and quality of life in the early phase after stroke, further analysis will need to be conducted when the complete study population is recruited to verify these findings.

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Introduction Rehabilitation activities of a sufficient intensity are necessary for optimal recovery in individuals with spinal cord injury (SCI). Optimizing rehabilitation and activity prescription requires quantification of physical activity and its predictors during this time. Purpose To determine, during inpatient rehabilitation, the: 1) reliability and validity of measures of physical activity. 2) level of physical activity using objective and self-report measures. 3) level of cardiovascular stress experienced during physical therapy (PT) and occupational therapy (OT). 4) variables associated with greater time spent at higher heart rate during PT.5) number of active movement repetitions occurring during PT and OT.Methods Design: A test retest design was used to determine the reliability of physical activity measures. A longitudinal observation design was used to determine movement repetitions and physical activity levels. A cross-sectional observational design was used to determine the level of cardiovascular stress. Subjects: Participants (n=108) were recruited from consecutive admissions to rehabilitation. Results Good reliability for accelerometry and step counts, and moderate reliability for self-report, was demonstrated. Validity was demonstrated for wrist accelerometry and step counts but not self-report physical activity. For most groups and variables, no changes occurred during therapy time from admission to discharge. Outside of therapy all groups increased from admission to discharge in accelerometer measured activity kilocounts but not self-report minutes, where the majority of time was spent in leisure time sedentary activity (~4.5 hours). The average time spent at a heart rate within the cardiovascular training zone was 6.0±9.0 minutes in PT and lower in OT. Lower spasticity, higher exercise self-efficacy, and better orthostatic tolerance correlated with a greater amount of time within a cardiovascular training zone. Average repetitions for PT and OT combined did not exceed 300 for the upper or lower extremity. Most repetition variables remained unchanged over the inpatient rehabilitation stay while clinical outcomes improved significantly. Conclusions Individuals report that a large amount of time is spent engaged in higher intensity activities. Measurement of heart rate during therapy sessions shows little time is spent at intensities sufficient to accrue cardiovascular benefits. Repetitions in therapy are low compared to the motor learning literature.

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Introduction: Anterior cruciate ligament (ACL) injury remains one of the most common and debilitating knee injuries in sport. Neuromuscular training programs show promise in improving biomechanical risk factors but we do not know which aspects of these programs are effective. There is a need to investigate the effect of specific movement strategies in reducing biomechanical risk factors for ACL injury. Purpose: 1) To evaluate the reproducibility of biomechanical variables at the knee during threesoccer-specific tasks (Chapter 2). 2) To determine the feasibility of implementing a novel movement strategy (Core-PAC) into a soccer team warm-up (Chapter 3). 3) To determine whether the Core-PAC would improve biomechanical variables during thethree tasks after immediate instruction and after a four-week training program (Chapter 3). 4) To conduct a randomized controlled trial (RCT) to compare a Core-PAC trained group to a control group for biomechanical variables during the three tasks after a six-week training program (Chapter 4). Methods: Design: A test-retest design was used for the reliability study (Chapter 2). A single group pretest-posttest design was used for the feasibility study (Chapter 3). An RCT was used inChapter 4. Subjects: A cohort of female soccer players (n = 10) participated in the reliability study (Chapter 2) and the feasibility study (Chapter 3). A different cohort of female soccer players participated in the RCT (n = 20) (Chapter 4). Results: Chapter 2: Adequate reproducibility (flexion angles (ICC=0.88-0.95; SEM=1.0-1.9°); abduction moments (ICC=0.62-0.84; SEM=0.1-0.5 Nm/kg) were demonstrated during the three tasks.Chapter 3: Feasibility of implementing the Core-PAC into a soccer warm-up was demonstrated. After immediate instruction, there were significant increases in peak flexion angles (3.5-6.4°) and decreases in abduction moments (0.17-0.27 Nm/kg) during the three tasks. After the training program, some individuals showed improvement. Chapter 4: The Core-PAC group improved (P 0.05) flexion angles during the side-hop task (6.2°) after training and during the side-cut (8.5°) and side-hop (10°) tasks after reminding them to use the Core-PAC. Conclusions: The results of this study suggest that the Core-PAC may be one method of modifying high-risk movements to reduce the risk of ACL injury.

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Introduction Approximately 70% of individuals with stroke have upper limb impairment. Inability to use the upper limb can lead to difficulties in activities of daily living. Increased time spent in therapy improves outcome of the upper limb post stroke however, length of stay in rehabilitation has decreased. Innovative ways of increasing therapy intensity need to be explored. Purpose1) To undertake a meta-analysis to determine the treatment effect of upper limb strengthening on strength, function and activities of daily living.2) To determine the effectiveness of a four week self-administered in-patient homework exercise program (GRASP) on upper limb function and depressive symptoms in individuals in the sub-acute stage of stroke recovery.3) To determine modifiable predictors of upper limb function in individuals in the sub-acute stage of stroke recovery. MethodsDesign: Chapter 2 is a meta-analysis of upper limb strength training in individuals with stroke. Electronic databases were searched from 1950-September 2008. 14 articles were reviewed.Chapter 3-5 involved a four week multi-site single blind randomized controlled trial of a self-administered upper limb exercise program (GRASP) compared to control. Subjects: 103 individuals with stroke were recruited from four rehabilitation units. ResultsChapter 2: The meta-analysis showed strength training is effective in increasing paretic upper limb strength and function but not performance in activities of daily living. Chapters 3-5: The GRASP program improved upper limb function significantly more than the control group (p0.001) and reported less depressive symptoms (p0.001). Baseline Fugl-Meyer, change in grip strength, treatment intensity and family involvement were significant predictors of upper limb function (R²=0.507 to 0.597, p0.001). ConclusionsStrength training is a viable method to improve upper limb function in individuals with stroke. The randomized controlled trial showed that a self-administered homework exercise program for the upper limb is an effective method for 1) improving upper limb function and 2) decreasing depressive symptoms among individuals with sub-acute stroke. The trial provided evidence that modifiable variables are significant determinants of upper limb function among individuals with stroke. Further studies to evaluate the GRASP protocol within other conditions and treatment settings are warranted.

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