Elisabeth Bruyere Research Institute

Ottawa, Canada

Elisabeth Bruyere Research Institute

Ottawa, Canada
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Bisson E.J.,University of Ottawa | Bisson E.J.,Elisabeth Bruyere Research Institute | Lajoie Y.,University of Ottawa | Bilodeau M.,University of Ottawa | Bilodeau M.,Elisabeth Bruyere Research Institute
Experimental Brain Research | Year: 2014

The reduction in the quality and integration of sensory information with aging could increase the alterations in postural control associated with muscle fatigue observed in younger adults. This study aimed to compare changes in postural control and attentional demands due to ankle muscle fatigue, with intact and reduced proprioceptive information at the ankle, between young and older adults. Eleven young (24 ± 4 years) and 13 older (65 ± 4 years) men stood quietly on a force platform (blindfolded) under four experimental conditions (combinations of firm (FS)/compliant (CS) surfaces and single/dual tasks), before and immediately after a fatiguing exercise. The fatiguing exercise, performed on a dynamometer, consisted of maintaining an isometric contraction of the plantarflexors at 50 % of maximum until exhaustion. Both COP sway area and COP sway velocity were greater on the CS compared to FS and increased with fatigue for both groups in all conditions. COP sway area showed a greater increase with fatigue in older adults when standing on the CS. Reaction time (secondary task) increased significantly after fatigue, but only for older adults when standing on the CS. The effects of fatigue on postural control are more important when proprioceptive information at the ankle is altered. In particular, older adults had more difficulty and may have needed more attention to stand quietly, compared with young adults. © 2013 The Author(s).

Master S.,Elisabeth Bruyere Research Institute | Tremblay F.,University of Ottawa | Tremblay F.,Elisabeth Bruyere Research Institute
NeuroReport | Year: 2010

Corticomotor facilitation was investigated using transcranial magnetic stimulation in healthy young adults when they actively stroked either their own left palm (intraactive) or the experimenter's palm (interactive touch) with their right index finger. We predicted, based on the sensory cancellation hypothesis, that corticomotor facilitation would be lower with intraactive touch. Motor evoked potential amplitude in the right first dorsal interosseous was affected by mode of touch, but not by sex. In contrast to our prediction, motor evoked potential facilitation was larger (mean 14%) during intraactive touch. The present results are in agreement with recent evidence suggesting that self-touch represents a unique class of sensorimotor experiences that are critical for the elaboration of internal body structure representation. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Townsend D.,Carleton University | Knoefel F.,Carleton University | Knoefel F.,Elisabeth Bruyere Research Institute | Goubran R.,Carleton University
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS | Year: 2011

Smart homes are proposed as a new location for the delivery of healthcare services. They provide healthcare monitoring and communication services, by using integrated sensor network technologies. We validate a hypothesis regarding older adults' adoption of home monitoring technologies by conducting a literature review of articles studying older adults' attitudes and perceptions of sensor technologies. Using current literature to support the hypothesis, this paper applies the tradeoff model to decisions about sensor acceptance. Older adults are willing to trade privacy (by accepting a monitoring technology), for autonomy. As the information captured by the sensor becomes more intrusive and the infringement on privacy increases, sensors are accepted if the loss in privacy is traded for autonomy. Even video cameras, the most intrusive sensor type were accepted in exchange for the height of autonomy which is to remain in the home. © 2011 IEEE.

Keller H.,University of Guelph | Chambers L.,Scientist Elisabeth Bruyere Research Institute | Niezgoda H.,Elisabeth Bruyere Research Institute
Journal of Nutrition, Health and Aging | Year: 2012

Use of modified texture foods (MTF) is common in the geriatric population. There is a potential for increased prevalence of use of MTF due in part to longer survival of persons with dementia, those who have suffered from a stroke, as well as other degenerative diseases that affect chewing and swallowing. Unfortunately, little clinical, nutritional and sensory research has been conducted on MTF to inform practice. This review highlights issues identified in the literature to date that influence nutritional and sensory quality and acceptability of these foods. Use of MTF is highly associated with undernutrition, however causality is difficult to demonstrate due to confounding factors such as the requirement for feeding assistance. Knowledge gaps and considerations that need to be taken into account when conducting research are identified.

Boyas S.,Elisabeth Bruyere Research Institute | Boyas S.,University of Ottawa | Hajj M.,University of Ottawa | Bilodeau M.,Elisabeth Bruyere Research Institute | Bilodeau M.,University of Ottawa
Gait and Posture | Year: 2013

The purpose of this study was to investigate the changes in postural control and in posture induced by ankle plantarflexor fatigue during a unipedal stance task. We also studied the postural strategies in the antero-posterior and medio-lateral planes used by participants to maintain balance. Thirteen young adults were asked to stand barefoot on their preferred leg as still as possible for 30. s with vision or without vision. Participants performed postural trials before and after a fatigue protocol that consisted of standing on toes until exhaustion. Centre of pressure (COP) displacements were measured with a force platform and electrogoniometers were placed at the ankle, knee and hip joints of the support leg to monitor articular angles. Relationships between changes in articular angles and displacements of the COP in the antero-posterior and medio-lateral planes were tested using cross-correlations. Sway area and velocity increased with fatigue, but only without vision. A posterior shift of the mean COP position was also observed after fatigue. Ankle and hip joints were more flexed after fatigue. Moderate to good relationships between COP displacements and ankle angles were observed before and after fatigue in both planes whereas these relationships were low for hip and knee joints. Ankle plantarflexors fatigue induced impairment in postural control and changes in posture. To compensate for the effects of fatigue, participants increased the flexion of the ankle and/or the hip joints but conserved the ankle strategy as the dominant postural strategy in both planes. © 2012 Elsevier B.V.

Miller D.I.,University of Ottawa | Taler V.,University of Ottawa | Taler V.,Elisabeth Bruyere Research Institute | Davidson P.S.R.,University of Ottawa | And 3 more authors.
Neurobiology of Aging | Year: 2012

Physical exercise and fitness have been proposed as potential factors that promote healthy cognitive aging. Support for this hypothesis has come from cross sectional, longitudinal, and intervention studies. In the present review, we discuss several methodological problems that limit the conclusions of many studies. The lack of consensus on how to retrospectively measure exercise intensity is a major difficulty for all studies that attempt to estimate lifelong impact of exercise on cognitive performance in older adults. Intervention studies have a much better capacity to establish causality, but still suffer from difficulties arising from inadequate control groups and the choice and modality of administration of cognitive measures. We argue that, while the association between exercise and preserved cognition during aging is clearly demonstrated, the specific hypothesis that physical exercise is a cause of healthy cognitive aging has yet to be validated. A number of factors could mediate the exercise-cognition association, including depression, and social or cognitive stimulation. The complex interactions among these 3 factors and the potential impact of exercise on cognition remain to be systematically studied. At this time, the best prescription for lifestyle interventions for healthy cognitive aging would be sustained physical, social, and mental activities. What remains unknown is which type of activity might be most useful, and whether everyone benefits similarly from the same interventions. © 2012 Elsevier Inc.

Young-Bernier M.,University of Ottawa | Young-Bernier M.,Elisabeth Bruyere Research Institute | Davidson P.S.R.,University of Ottawa | Davidson P.S.R.,Elisabeth Bruyere Research Institute | And 3 more authors.
Neurobiology of Aging | Year: 2012

Changes in motor cortical excitability were examined in 2 groups of participants, young (18-30 years of age, n = 25) and senior (65-82 years of age, n = 31), using paired-pulse afferent stimulation with transcranial magnetic stimulation (TMS). Motor evoked potentials (MEPs) elicited by TMS at suprathreshold intensity (120% motor threshold) were first recorded in unconditioned trials (TMS alone) and then in conditioned trials, in which TMS pulses were preceded by median nerve stimulation at 3 different interstimulus intervals (ISI; 20, 50, and 200 ms). Conditioning of MEP responses revealed a similar pattern of modulation in the 2 age groups, with 2 periods of inhibition at 20- and 200-ms ISIs, separated by a period in which MEPs tended to return to baseline at a 50-ms ISI. Afferent-induced inhibition at the short interval (i.e., SAI 20-ms ISI), was selectively reduced in seniors, with half of them showing either low or no MEP suppression. Age-associated changes in SAI level were also good predictors of performance on tests of processing speed and dexterity. The selective decrease in SAI exhibited by many seniors is consistent with reported alterations in intracortical inhibition with age. Our observations also highlight the potential value of SAI, as a putative marker of central cholinergic activity, in predicting declines in motor and cognitive function with age. © 2012 Elsevier Inc.

Parreira R.B.,University of Northern Paraná | Amorim C.F.,City University of Sao Paulo | Gil A.W.,University of Northern Paraná | Teixeira D.C.,University of Northern Paraná | And 3 more authors.
European Journal of Applied Physiology | Year: 2013

Muscle fatigue can influence the various mechanisms that regulate balance. Few studies have investigated the effects of trunk extensor muscle fatigue on postural control. The purpose of this study was to evaluate the impact of trunk extensor fatigue during a one-leg balance test in young and elderly adults, as well as to determine the time necessary to recover posture control after fatigue. A total of 36 subjects (18 elderly and 18 young adults) participated in the study. Subjects were tested on a force platform to assess the postural control parameters associated with center of pressure (COP) movements, before and after a fatiguing trunk extension-flexion exercise on a roman chair carried out to exhaustion. Post-fatigue effects and postural control recovery were investigated at different times in minutes (MIN): immediately post-fatigue (postIME), after 5 (rec5MIN), 10 (rec10MIN), and 20 min (rec20MIN). Elderly subjects had greater sway (P < 0.05) than young adults in all COP parameters. In both groups, there was an increase in postIME sway compared with pre-fatigue values for all COP parameters. However, the differences were significant only for the COP velocity parameter, with more pronounced effects in young adults that did not return to pre-fatigue values at the end of rec20MIN. The present study demonstrated a significant effect of trunk extensor muscle fatigue on postural control, which was more evident in young adults than in the elderly. © 2013 Springer-Verlag Berlin Heidelberg.

Kuziemsky C.E.,University of Ottawa | O'Sullivan T.L.,University of Ottawa | O'Sullivan T.L.,Elisabeth Bruyere Research Institute
Social Science and Medicine | Year: 2015

Common ground is necessary for developing collaboration as part of building resilience for public health preparedness. While the importance of common ground as an essential component of collaboration has been well described, there is a need for studies to identify how common ground develops over time, across individual and group dimensions, and the contexts that influence its development. This paper studied common ground development in three Canadian communities between October 2010 and March 2011 through a project on capacity building for disaster management. Disaster management requires the integration of paid and volunteer participants across public and private sectors and is therefore a good domain to study common ground development. We used directed qualitative content analysis to develop a model of common ground development over time that describes its progression through coordinative, cooperative and collaborative common ground. We also identified how common ground develops at micro (individual) and macro (group) levels, as well as how agency, technology and geographical contexts influence its development. We then use the four phases of disaster management to illustrate how our model can support longitudinal common ground development. Our findings provide useful insight to enable proactive development of common ground in collaborative health communities. © 2015 Elsevier Ltd.

Levac J.,University of Ottawa | Toal-Sullivan D.,University of Ottawa | Toal-Sullivan D.,Elisabeth Bruyere Research Institute | O'Sullivan T.L.,University of Ottawa
Journal of Community Health | Year: 2012

Global policies on disaster risk reduction have highlighted individual and community responsibilities and roles in reducing risk and promoting coping capacity. Strengthening local preparedness is viewed as an essential element in effective response and recovery. This paper presents a synthesis of available literature on household preparedness published over the past 15 years. It emphasizes the complexity of preparedness, involving personal and contextual factors such as health status, self-efficacy, community support, and the nature of the emergency. In addition, people require sufficient knowledge, motivation and resources to engage in preparedness activities. Social networks have been identified as one such resource which contributes to resilience. A predominant gap in the literature is the need for evidence-informed strategies to overcome the identified challenges to household preparedness. In particular, the construct of social capital and how it can be used to foster individual and community capacity in emergency situations requires further study. © Springer Science+Business Media, LLC 2012.

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