Now showing items 1-20 of 33

    • Effects of Exogenous Lipopolysaccharide Exposure on Bone Outcomes in Rodent Models

      Bott, Kirsten; Applied Health Sciences Program
      Chronic low-grade inflammation has been identified as a potential contributor to the pathophysiology of osteoporosis. A key mediator may be lipopolysaccharide (LPS) released from gram-negative bacteria in the gut that can enter circulation stimulating an inflammatory response and upregulate bone resorption. Since rodent models mimic the loss of bone mineral density (BMD) and structure that occurs in humans, rodents offer an accelerated model for studying these inflammation-mediated changes. Therefore, the objective of this thesis was to characterize a rodent model of LPS-induced bone loss using repeated in vivo μCT scans to establish a time course effect of LPS longitudinally and for this purpose three studies were conducted. Study 1 & 2 were run simultaneously using the same control mice. Study 1 demonstrated that repeated irradiation had a negative impact on trabecular bone in both male and female CD-1 mice, while cortical bone was only negatively impacted in the females. In study 2, continuous delivery of exogenous LPS via osmotic pumps for 12 weeks elevated serum LPS in both male and female CD-1 mice but did not alter trabecular or cortical bone structure or BMD at any of the scanning timepoints. Results from Study 2 may in part have been influenced by the effects of repeated irradiation from the in vivo μCT scans at 4-week intervals for a total of 4 scans analyzed in Study 1. In study 3, a systematic review was conducted to better characterize a model of LPS induced bone loss and identify factors that may impact the effects of LPS on bone outcomes in rodent models. Regardless of study duration, exogenous LPS negatively impacted trabecular bone structure and BMD but not cortical bone structure, due to an upregulation in bone resorption. Together these data suggest that exogenous LPS can induce alterations in bone structure and BMD in rodent models, however a clearly defined model of exogenous LPS induced bone loss has yet to be fully characterized.
    • The Role of Protein Following Intense Exercise in Competitive Youth Athletes

      McKinlay, Brandon; Applied Health Sciences Program
      The overall purpose of this thesis was to examine the role of post-exercise dairy protein consumption (isolated and whole-food) on recovery indices (performance and muscle damage) and inflammation following intense exercise within the context of different ecologically valid sporting environments, i.e., acute competition and a short-term period of intensified training, in competitive youth athletes. For this, two studies were conducted. Study 1 (Chapter 3) investigated the effect of whey protein consumption following a high-intensity interval swim session (HIIS) among adolescent swimmers on subsequent performance, muscle soreness, plasma creatine kinase and inflammatory cytokines, compared with isoenergetic carbohydrate and flavoured water in the acute (0–8 h) and short-term (8–24 h) recovery periods. Study 2 (Chapter 4) examined the effects of increased protein consumption, via plain Greek yogurt, compared with an isoenergetic carbohydrate control on performance recovery, inflammation, and muscle damage, during a 5-day simulated soccer training camp in competitive adolescent female soccer players. The collective findings indicate that during both acute and short-term periods of intensified exercise, the provision of dairy protein regardless of form (isolated or whole food), provided no added benefit at enhancing performance recovery or ameliorating muscle damage above that of energy matched carbohydrates. However, it does appear that the consumption of calories, regardless of type (e.g., carbohydrates or dairy protein), when rapid recovery is required, offers greater performance retainment than water. Therefore, during periods of intensified exercise that may be accompanied by inadequate recovery, the replenishment of energy should be the primary focus. Further, in both studies the consumption of dairy protein following exercise leads to an augmented anti-inflammatory response (i.e., increased IL10), not observed in the control conditions (i.e., water or energy-matched carbohydrates). Thus, it is possible that dairy protein consumption post-exercise may benefit the acute immune response. This possibility requires further study.
    • Tea types and their effects on in vitro mineralization and in vivo bone structure and density

      McAlpine, Michael D.; Applied Health Sciences Program
      The consumption of tea has many proposed health benefits thought to likely be the result of an abundance of unique polyphenols. In particular, one exciting potential health benefit of tea is its capacity to have bone supportive effects when consumed throughout life. Prior to testing the potential bone supportive effects, it was important to characterize several types of tea and determine the ideal steeping time for each tea, maximizing the quantity of polyphenols while also maintaining taste (Study 1). Results from this study were congruent with manufacturer’s recommendations. Following this, several types of teas and tisanes were tested in an in vitro osteoblast model to determine if there were any alterations in quantity of mineral produced (Study 2). Findings demonstrated that all teas effectively increased mineralization at a dietary concentration of polyphenols, but red rooibos tea appeared to produce the greatest effects. The next important aspect which needed to be clarified was if there was an optimal concentration of red rooibos tea that elicited maximal results (Study 3). To determine this, a dose response study was conducted in the same osteoblast model as study 2 and mineral quantity was measured. From this study a positive dose-dependent response was observed without any signs of toxicity, suggesting that high concentrations may be beneficial. Following the initial in vitro studies it was important to test red rooibos tea in a physiologically relevant model of elevated bone turnover, pregnancy and lactation (Study 4). Female Sprague-Dawley rats were randomized to one of the following groups: PREG TEA (pregnant and received a supplemental level of red rooibos: ~2.6 g /kg body weight/day in water), PREG WATER (became pregnant and received water), or NONPREG CON (age-matched, non-pregnant control) from 2 weeks prior to pregnancy (age 8 weeks) through to 4 months post-lactation. Results demonstrated that there were immediate losses of both trabecular and cortical bone following lactation. However, cortical bone rapidly recovered in both pregnancy groups while the majority of trabecular outcomes only partially recovered and appeared to have permanent reductions. When comparing the two pregnancy groups, there were no differences in cortical bone post-lactation but there were significant improvements in several of the trabecular outcomes in rats that received red rooibos herbal tea. The findings from this thesis demonstrated in progressively more complex and physiologically relevant models that tea does have the capacity to be bone supportive, particularly during periods of high turnover.
    • Exploring Mental Health in Sport: The Behaviors, Perspectives and Needs of Stakeholders

      Murphy, Jessica; Applied Health Sciences Program
      Student-athletes are at high risk for poor mental health. Leaders within the varsity sport environment influence athlete mental health and help-seeking. This dissertation explored the behaviors, perspectives and needs of athletes, coaches, and athletic trainers as it pertains to mental health in sport. Three studies were conducted, the first utilized the Theory of Planned Behavior to explore factors associated with coach-athlete conversations about mental health. A coach’s Attitude towards having a conversation with an athlete significantly influenced their Intention to do so. Perceived Behavioral Control (PBC) significantly influenced the relationship between Social Norms and Intention. Both PBC and Social Norms had a significant relationship with the Behavior (having a conversation about mental health with an athlete). The second study applied a conceptual model from Horn’s Working Model of Coach Effectiveness to explore how an athlete’s perception of coach behavior impacts attitudes and help-seeking behaviors. Psychological distress levels influenced an athlete’s Perception of their coach’s behavior. Openness to help-seeking was significantly related to help-seeking Behaviors and influenced the relationship between personal characteristics and help-seeking. Perception of coach behaviors influenced the relationship between psychological distress and help-seeking from a coach. The last study sought to determine the acceptance of an online varsity sport-specific mental health resource. Preliminary results were promising; The PEER Network was frequently used over the study period and participants had positive and supportive feedback. Overall, results from the three studies suggest that perceived ability and social support may influence whether coach-athlete conversations about mental health occur. Due to the effects of these variables, coach mental health training should focus on improving the skills required for these conversations and normalizing mental health in sport. As an athlete’s perception of coach behavior mediated the relationship between psychological distress and help-seeking, training should also focus on clear ways to show athletes that coaches are supportive of mental health. Athlete-specific training should try and improve attitudes towards help-seeking and highlight the value from seeking help. The PEER Network may be an easily accessible and context-specific way of achieving these educational goals for members of the varsity athletic community.
    • Teachers’ Experiences of Implementing a Pedagogical Approach for Meaningful Physical Education

      Beni, Stephanie; Applied Health Sciences Program
      Dominant forms of physical education (PE) have been criticized for their inability to promote lifelong movement, with many scholars arguing in favour of an approach oriented toward meaningful experiences in PE. The Meaningful PE approach has been designed in response to this but has yet to be tested extensively in practice. The purpose of this dissertation has been to study teachers’ experiences of learning about and implementing the Meaningful PE approach. Five teachers based in Ireland and 12 teachers based in Canada participated in two separate studies lasting eight weeks and across two school years, respectively. Qualitative data were collected in the form of semi-structured interviews, non-participant observations, community of practice (CoP) meeting transcripts, and reflections. Results of this dissertation are presented in four articles. Article One highlights the experiences of Irish primary classroom teachers, demonstrating preliminary support for the approach from classroom teachers with little background in PE. Article Two focuses on Canadian elementary teachers’ experiences of implementing the Meaningful PE approach with their students and on the factors that influenced their implementation decisions. Primary factors influencing implementation included teachers’ prior experiences and beliefs, students’ responses to the implementation process, and external organizational pressures. Article Three focuses on Canadian teachers’ experiences of learning about Meaningful PE through a professional (PD) initiative designed around characteristics of effective PD outlined in the literature. Teachers were most supportive of the use of a CoP and modelling of the approach to foster their learning about Meaningful PE, while also highlighting several tensions between ideal and practical forms of PD, taking personal and organizational barriers into account. Article Four focuses on my experience of becoming a facilitator of teachers’ PD through facilitating a CoP for teachers. This article highlights the important role of identity in the process of learning to become a facilitator and navigating the tensions associated with that process. Collectively, this dissertation makes a significant contribution to the literature by a) informing the refinement of the Meaningful PE approach, b) offering insights into educational implementation research, and c) adding to the literature on teachers’ professional learning when being introduced to innovations.
    • "(Having?) Doing it All”: A Narrative Exploration of Self-Care and Well-being for Generation X Women at Midlife

      Petty, Lisa; Applied Health Sciences Program
      Inspired by my own experiences as a woman moving through midlife, the purpose of this research was to better understand the lived experience of Generation X women. Specifically, the study investigated the relationship between self-care and well-being as the women navigate their changing bodies and negotiate, resist and/or reproduce social role expectations. Using a critical constructivist perspective and guided by the Life Course framework, this narrative study involved two reflexive, dyadic interviews with 21 Generation X women (born between 1965-1980). As part of the study, women took photographs that represented their experiences, and the images and narratives were included in the data. Use of Reissman’s (2008) narrative thematic analysis revealed four major thematic areas: (a) The Multiple Meanings of Self-Care: It’s Whatever is Important to You, (b) The Big Lie: Having Doing it All, (c) Who is she? What is this?: Changing Bodies, and (d) Navigating Self-Care: Something has to Give. Each thematic area is comprised of several subthemes that narrate the women’s experiences. Thematic areas are first presented in pastiche form, which is a representation much like a quilt that provides a weave of participants’ co-existing meanings (Ely, Vinz, Downing, & Anzul, 1997). The pastiche is then followed by written thematic analysis of the findings using verbatim quotations from participants, as well as my own personal reflections. Taken together, the findings highlight the myriad ways the social backdrop of ‘having it all’ has influenced the life experiences and well-being of these women. More precisely, findings show how the women reproduce and resist social role expectations placed on them in the practise of their self-care, and introduces the concepts of mindful connection, self-care shaming and the archetypal Crone to the self-care literature. As the experiences of Generation X women have largely been ignored in research across disciplines, this research provides important contributions to the self-care literature and its connections to well-being for women.
    • Can exergaming improve mental health of university students?

      Santos, Esther; Applied Health Sciences Program
      The academic, financial, and social pressures that emerge when adults begin university may lead them to encounter mental health challenges (American College Health Association [ACHA], 2016). In Ontario, 46.2% of university/college students have reported ‘excessive’ stress whereas 64.5% report ‘overwhelming’ anxiety (ACHA, 2016). One approach that may be useful for enhancing mental health is exergaming which uses motion-sensor technology requiring players to move their bodies to complete the videogame sessions (Huang et al., 2017). However, studies focused on the effectiveness of exergaming for improving mental health of university students are scarce in number and limited in scope. The overall purpose of this dissertation was to examine the role of exergaming in relation to mental health reported by university students. In Study 1, a synthesis of published intervention research using exergaming to change well-being – a psychological concept affiliated with mental health – reported by adults was conducted. Results from Study 1 indicated that less than 50.0% of the coded studies - using either multi- or single-group (pre-post-test) research designs - reported enhanced well-being as a function of exergaming. In Study 2, the link between the amount and intensity of exergaming behaviour per week and mental health reported by university students was evaluated. Results from Study 2 indicated that university students who reported more frequent exergaming behaviour during a typical week displayed lower anxiety and stress plus higher flourishing and vitality. In Study 3, the contributions of exergaming to mental health of university students were investigated using an experimental research design that compared exergaming against other physical activity behaviours and self-management approaches. Results from Study 3 showed that ‘exergamers’ did not present higher or lower mental health scores compared against ‘traditional’ exercisers but displayed less stress and anxiety when compared against pet therapy, as well as, higher vitality plus lower stress and anxiety compared to ‘non-exercisers’. The results from these studies make it apparent that exergaming may not offer anything ‘unique’ as a stimulus beyond more traditional modes of exercise, but it fosters mental health of university students.
    • Future-proofing: Exploring the value of a therapeutic recreation positive psychology intervention for supporting youth experiencing mental health challenges

      Cripps, Lauren C.; Applied Health Sciences Program
      In Canada, suicide remains the second leading cause of death for individuals aged 15 to 24, exceeded only by unintentional injuries (accidents). In 2012, suicide accounted for 15% of deaths among youth aged 10-14 years, 29% among youth aged 15-19 years and 23% among young adults aged 20-24 (Statistics Canada, 2017). Recovery supports the development of a meaningful life (as described by the individual) that includes enhanced traits and practices that are specifically intended to maintain one’s level of satisfaction in everyday life, while supporting the management of recurring symptoms and/or changes in current life circumstances (Andresen, Oades, & Caputi, 2011; Kleiber, Hutchinson, & Williams, 2002; McCormick & Iwasaki, 2008; McCormick & Iwasaki, 2008; McCormick, 1999). This recovery-oriented project was a qualitative, interpretative phenomenological study guided by the evidenced-informed process as a framework for program design, implementation and evaluation. This project sought to critically explore mental health as it pertains to adolescents through the design, implementation and evaluation of a therapeutic recreation intervention designed for youth living in a residential treatment setting. This project provides evidence that the BYBS-Y program has the potential to support change with the participants. This project also demonstrates new learning and is an illustration of the potential connection between a strengths perspective and supporting essential tasks assigned to development and recovery. By implementing a three-phase process this research shows the value of feedback from both practitioners and clients, affirming that our greatest insights are always gained from those with lived experience. Finally, this project provides evidence for the contribution of TR services in the recovery process, suggesting that by focusing on the development of skills and capacities that are likely to generate emotion, highlight strengths, support choice and create opportunities for positive social connections, it is likely that youth can increase the resiliency necessary to buffer the effects of chronic symptoms and in turn begin to envision (and obtain) a life that includes, but is not defined by illness.
    • Lessons learned from a critical appraisal of a fall break policy in higher education: A case study

      Pilato, Kelly A.; Applied Health Sciences Program
      The incidence, severity and persistence of mental health issues is increasing across post- secondary campuses (Zivin et al., 2009; Canada Newswire, 2012) with these students now viewed as a high-risk population (Stallman, 2010). Many Canadian universities are implementing a policy for a fall break in hopes of alleviating students’ stress and anxiety in order to improve mental health, heighten retention, and increase academic productivity. To date, there is limited empirical evidence to guide the development of policy and the delivery of effective practices to alleviate school-related stress and anxiety. This thesis is presented as a three paper, manuscript approach. The focus of this project was to appraise the development and implementation of a fall break and then evaluate its effectiveness in an effort to address rising concerns related to mental health for post-secondary students. Three thousand and seventy-one students in years one to four completed a post-break survey during one week in January of 2013, 2014, 2015. Of those, 1019 were male and 2052 female. Thirty-three students varying in years from one to four participated in focus groups in February of 2013, 2014, 2015. Of those 4 were male and 19 were female. Ten faculty from varying faculties and one informant participated in interviews in spring, 2018. Analyses from the surveys revealed that overall, students are in favour of having a fall break. Even though a small percentage of participants perceived their workload to go up before and after the break, 90% of students agree that the fall break was useful in reducing school related stress levels. However, the focus group, faculty and informant interviews revealed that the timing of the fall break had an impact on how students and faculty experienced the break and thus influenced perceptions on the impact that the break had on student mental health. Comprehensive evidence about whether a fall break policy supports or undermines the mental health of students needs to be assessed using a range of indicators before its implementation. This will help post-secondary institutions determine whether a break in the fall semester can be an effective approach to addressing students’ stress and anxiety.
    • Examining Student Preparation for Certification Examination: An Exploratory Case Study

      TAYLOR, HELEN CATHERINE; Applied Health Sciences Program
      This research paper explores three university-level programs with mandatory licensing exams for graduates who wish to attain professional certification. Specifically, the study explored the affordances and constraints associated with curricular alignment and program accreditation, student success on licensure, and student satisfaction. The specific programs and the licensure exams are: the Bachelor of Science in Nursing (BScN), who are eligible to take the National Council Licensure Examination-Registered Nurse (NCLEX-RN), the Master of Applied Disability Studies (MADS), who write the Behavior Analyst Certification Board Exam, and the Bachelor of Accounting/Master of Accountancy (BAcc/MAcc), who are eligible to take the Chartered Professional Accountants (CPA) Common Final Examination (CFE). The study used a scoping review of the literature specific to the NCLEX-RN to help inform an exploratory case study of three academic programs that are offered through a University in Ontario, all leading to licensure exams. The programs are designed to ensure that students are prepared to write the licensure exams and provide more material that is integral to the practice but is not necessarily tested on the licensure exam. Using curriculum and accreditation review processes, administrators/faculty and students can provide insight into processes that could aid future students for licensure exams. When comparing the findings from analyses of transcripts from one program and documents across all three programs, it is apparent that there are many similarities across the programs despite the differences in the actual curricular goals and licenses. However, there appears to be a disconnect in the Nursing program, since they use the greatest number of the identified techniques/tools, but still have lower percentages of first-time pass rates than the other two programs. This provides an area for future study and analysis.
    • Exploring the Ecological Self: An Interpretive Phenomenological Analysis with Gifted Adults

      Windhorst, Eric; Applied Health Sciences Program
      The nature connectedness research suggests that (re)creating human-nature connections can address both escalating ecological issues and rising mental health concerns by fostering (ecological) self-realization. Given that the nature connectedness literature oversimplifies experience of ecological self, however, there remains a need to explore lived ecological self experience, and how this experience influences mental health and environmental behaviour. In this exploratory interpretive phenomenological analysis (IPA), I sought to flesh out the nature connectedness research by investigating ecological self experience among a small group of gifted adults (n=8) who measure relatively high in nature connectedness. Three research questions guided the study. The project’s primary research question was: How do gifted adults experience ecological self? Two secondary, theory-driven sub-questions refined the project further: 1. How does experience of ecological self influence mental health? 2. How does experience of ecological self influence environmental behaviour? Analysis of data collected via two semi-structured interviews held with each participant reveal that while ecological self experiences might often enhance mental health, nature experiences can also be intense, distressing, and/or ambivalent, and environmental concerns can precipitate anguish and anger. Findings also illustrate how experience of ecological self can be inconsistent: conceptions of the human-nature relationship varied, and experience of ecological self seemed to oscillate along with diurnal and seasonal cycles and appeared to evolve over the lifespan. Finally, results demonstrate that while ecological self experience may motivate pro-environmental behaviour, movement from experience to action is not automatic. Findings show how a variety of intra- and interpersonal factors can hinder pro-ecological engagement. Taken together, study results nuance the nature connectedness literature by illustrating the complexity of ecological self experience. While (re)creating human-nature connections can be considered one approach to addressing escalating ecological issues and rising mental health concerns, findings from this project suggest that the back-to-nature strategy is not a cure-all.
    • Effects of local muscle temperature manipulations on neuromuscular function

      Mallette, Matthew M.; Applied Health Sciences Program
      Human muscle can operate through a wide range of temperature; however optimal function may occur throughout a much narrower range. Muscle cooling results in an impairment in muscle contractile properties and maximal force, whereas heating the muscle fosters faster and more powerful contractions. However, what neural compensatory mechanisms exist such that the muscle can still function adequately throughout a wide range of temperatures are unknown and forms the purpose of this dissertation. To this end, muscle contractile and motor unit properties of the flexor carpi radialis were examined during three separate projects involving forearm temperature manipulations. Chapter 4 investigates the effects of local forearm cooling on motor unit properties during an isometric wrist flexion contraction to 50% of baseline maximal force. Chapter 5 builds upon Chapter 4 to include local heating and contraction intensities above and below the motor unit recruitment range of the flexor carpi radialis. Finally, Chapter 6 investigates how different muscle temperatures affect manual performance – assessed through a staircase isometric force tracking task. Local cooling did not affect the ability to perform voluntary contractions to 50% of baseline force, but motor control was achieved through changes in the relationship between motor unit firing rate and recruitment threshold, indicating either faster motor unit firing rates and/or earlier motor unit recruitment to accomplish a task at the same absolute force (Chapter 4). However, these differences were not present when force requirements were made relative to muscle capacity of the respective temperature conditions. We found that motor units were recruited earlier in the cold when contraction intensity was above the motor unit recruitment range (Chapter 5). The altered relationship between motor unit firing rate and recruitment threshold observed in Chapter 4 with muscle cooling at an absolute force level did not affect isometric force tracking ability (Chapter 6). Collectively, this thesis found that the motor unit recruitment threshold may be depressed in the cold due to cutaneous stimulation, and that manual function during an isometric force tracking task involving relatively light loads is not impaired with muscle temperature changes.
    • Sclerostin Response to Exercise: Association with Bone Turnover, Oxidative Stress and Inflammation

      Kouvelioti, Rozalia; Applied Health Sciences Program
      The purpose of this thesis was to compare the response of sclerostin, a bone-specific glycoprotein that downregulates bone formation, to two modes (high impact vs non-impact) of high intensity interval exercise and to examine its relationship to potential exercise-induced changes in bone turnover (Study 1), oxidative stress (Study 2) and inflammation (Study 3). For the three studies included in this thesis, 40 healthy, young (18-25 years old) female and male adults performed two high intensity interval exercise trials in random order. Trials consisted of eight repetitions of 1 min high intensity running or cycling (mean heart rate 90% of maximum), separated by 1 min passive recovery intervals between repetitions. Blood samples were collected pre-exercise, and 5 min, 1h, 24h and 48h post-exercise. Sclerostin, bone turnover markers (cross linked telopeptide of type Ⅰ collagen [CTXI], procollagen type I amino-terminal propeptide [PINP]), oxidative stress markers (thiobarbituric acid reactive substances [TBARS], protein carbonyls [PC]) and inflammatory cytokines (interleukin-1β [IL-1β], -10 [IL-10], -6 [IL-6], and tumor necrosis factor-alpha [TNF-α]) were measured in serum. In the first two studies, sclerostin showed a significant time effect, but no significant exercise mode effect or interaction in both females (study 1) and males (study 2). In study 3, sclerostin showed a significant main effect for sex and a significant sex-by-time interaction. Specifically, sclerostin significantly increased from pre- to 5 min post-exercise and returned to baseline levels within 1h post-exercise with greater increase in males than females (47% vs. 34%, respectively). Furthermore, there were no correlations between sclerostin’s exercise-induced increase and the corresponding changes in bone turnover and oxidative stress markers. In contrast, sclerostin’s increase 5 min post-exercise was significantly correlated with the corresponding increase in the inflammatory cytokines, especially TNF-α, which along with sex, significantly explained 34% of the variance in its post-exercise elevation. In conclusion, in both young females and males, one session of high intensity interval exercise leads to an increase in sclerostin immediately post-exercise, and this increase is of similar magnitude following high impact and no impact exercise. Furthermore, the increase in sclerostin 5 min post-exercise seems to be associated with the exercise-induced inflammation.
    • Sex differences in the neural control of muscle

      Inglis, J Greig; Applied Health Sciences Program
      Sex-differences in muscle strength have been linked to differences in muscle size, involved limb, and daily activities. Early work has shown that sex-differences are greater in the upper compared to lower limb, making the upper limb an ideal model to investigate the best statistical approaches for sex comparison. Large differences in the upper limb reveals how biomechanical factors may impact neural control. Since males and females are more comparable with respect to strength in the lower limb, it allows for a determination of whether potential sex-differences in neural control exist without large differences in biomechanics. Understanding sex-differences allows for prescription of rehabilitation and training modalities, taking into account potential specificities in sex-related neuromuscular and musculoskeletal factors. The overall purpose was to examine neural and biomechanical differences that would account for sex-differences in neural control of muscle. Manuscript 1 examined normalization versus an ANCOVA to assess sex-differences. Sex-differences were seen in elbow flexor strength and rate of force development (RFD). Normalization by either maximum strength or neural factors couldn’t account for all sex-differences in RFD, resulting in an ambiguous interpretation. In contrast, both variables were able to be incorporated in an ANCOVA to determine their relative contribution. Manuscript 2 examined the effect of task familiarization and the contribution of maximum strength, twitch contraction time, muscle fiber condition velocity, and rate of muscle activation to sex-differences in the RFD during dorsiflexion. There were no significant differences between the sexes in muscle properties, but there were differences in neural control. Additionally, across days females exhibited a neural adaptation leading to an improvement in the RFD. Manuscript 3 directly assessed potential sex-differences in neural control during force gradation by recording motor unit activity during maximal and submaximal contractions. Females had less force steadiness (FS), which may have resulted from neural compensation for a less optimal pennation angle or a tendency towards greater joint laxity. Higher motor unit discharge rates and incidence of doublets may increase twitch force summation leading to a reduction in FS. Thus, biomechanical, not inherent sex-differences in neural drive led to neural compensation strategies manifesting as a difference in FS.
    • Designing, Testing, and Implementing BIAS (Body Image Awareness Seminars): A Positive Body Image Program

      Bailey, Kaytlin Alysse; Applied Health Sciences Program
      Dissatisfaction with the body is prevalent in North America and body image researchers have called this phenomenon a norm, suggesting it is abnormal for people to love their bodies. Positive body image programs are needed now more than ever but currently they are scarce, and this is especially true for individuals outside adolescent and university student populations. This dissertation describes the design, testing, and implementation of a new positive body image program called BIAS (Body Image Awareness Seminars). This program is unique in three ways: 1) it was created by working with participants using action research, 2) it is applicable to a diversity of people including older adults and people with physical disabilities, and 3) it was informed by positive body image research. In study 1, initial interviews and focus group meetings revealed a potential knowledge gap in understanding body image between body image researchers and the non-academic community. Participants described a need to understand body image better in order to improve their body image experiences. This study led to the conclusion that psychoeducation is an important component of a positive body image program which significantly informed the design of BIAS. Study 2 describes the creation of BIAS using action research. Very few body image programs have been designed using participatory methodologies. Instead, most body image researchers create and implement body image interventions without any participant feedback. Study 2 highlights both the advantages and disadvantages of using action research in the design, testing, and implementation of the BIAS program. Study 3 is an evaluation of the effectiveness of BIAS. Using mixed methods, qualitative and quantitative data were analyzed and both concordance and discordance of results were reported. Participants’ body image was found to significantly improve and this improvement was sustained 6-weeks later. Additional findings include participants experiencing self-compassion, greater knowledge about body image, and becoming positive body image advocates. Study contributions to both the body image and mixed methods literature are discussed.
    • The Examination of Potential Mechanisms Underlying the Cross Education Phenomenon

      Green, Lara; Applied Health Sciences Program
      Cross education is the strength or skill gain that is found in the contralateral, homologous limb following a unilateral training program or practice. This phenomenon provides a beneficial rehabilitation model for unilateral injuries or neurologic disorders, such as stroke. Although the cross-body transfer of strength and skill are each widely studied, they are rarely examined concurrently, despite each contributing to the goal of functional movement rehabilitation. Therefore, the overall purpose of this thesis was to examine the neuromuscular adaptations of unilateral resistive exercise training contributing to the transfer of strength and skill, while employing the necessary methodological controls that have been under-examined and under-used. The assessment of neuromuscular mechanisms requires both voluntary and evoked contractions to be performed simultaneously. Therefore Manuscript 1 examined a novel electrode configuration, consisting of one electrode on the electrically identified motor point and the second electrode directly adjacent in a bipolar configuration. Both voluntary surface electromyography measures and evoked potentials were found to be reliable (ICCs > 0.75) and effective across multiple test sessions. Manuscript 2 was a comprehensive review of 90 unilateral training studies in young and older able-bodied participants and in patient populations. The cross education strength gain was estimated at 18% in young, and 17% in older able-bodied participants. The cross education strength gain was 29% in patient populations consisting of post-stroke, multiple sclerosis, osteoarthritis, and neuromuscular disorder patients. The meta-analysis identified the efficacy of electromyostimulation (EMS) training over voluntary training modalities. The magnitude of strength transfer was similar between upper and lower and between males and females. Lastly, manuscript 3 consisted of a 6-week unilateral training program resulting in contralateral strength gains of 11% in the wrist flexors and 15% in the dorsiflexors. A continued increase in contralateral strength at retention demonstrated the persistence of cross education following 6-weeks of detraining. Skill transfer in the contralateral limbs was evident in the force variability measures calculated during contractions without concurrent feedback (noKR). Agonist RMS amplitude, V-wave amplitude, and central activation ratio indicated neuromuscular adaptations; however, there was no change in motor unit firing rates at 60% of maximal force.
    • On the Ball Implementation of Canada Basketball’s Athlete Development Model

      Whitaker-Campbell, Tammy; Applied Health Sciences Program
      The purpose of this dissertation was to explore the perceived benefits and challenges of Canada Basketball’s athlete development model (ADM)/long-term athlete development (LTAD) by administrators, learning facilitators, and coaches at Canada Basketball to better understand the barriers to and enablers of this process. The methodological approach used for the study was an exploratory case study. Methods were established that were consistent with the iterative nature of case study. In total, 5 participants who identified as administrator/learning facilitator/coach, 6 participants who identified as /learning facilitator/coach, and 1 participant who identified as a coach participated in the study. In-depth semi-structured interviews were conducted with each participant that provided new insight into participants’ perceptions of and experiences with ADM/LTAD relative to their positions. Analysis revealed themes related to perceived (a) benefits while using ADM/LTAD; and (b) and challenges with using ADM/LTAD. These findings provide a preliminary assessment of one sport specific athlete development model and may inform research of other sport-specific athlete development programs. Several implications of the study findings are discussed and suggestions are posed for future research.
    • Mind over Matter: Exploring the Power of a Positive Body Image

      Cline, Lindsay; Applied Health Sciences Program
      This dissertation examines positive body image and its relationship with appearance-related commentary, body weight, and impression formation among young adult women. It explores how women’s unique individual experiences are constructed within social interactions. The present dissertation examined weight using a dynamic approach - weight trajectory (i.e., whether someone is gaining, losing, or maintaining weight). In study 1, body appreciation and a body image coping strategy (i.e., positive rational acceptance coping), which are characteristics associated with positive body image, were tested as mediators in the relationship between the frequency of positive appearance-related commentary and the effect elicited from those compliments. Only body appreciation produced indirect effects, as the frequency of appearance compliments only impacted the effect felt from those comments through body appreciation as the processing mechanism. In study 2, women were interviewed about their body image experiences with appearance-related commentary at differing weight trajectories. Women described how their body image was influential in filtering appearance-related commentary both while a higher and lower body weight. A more positive mindset (e.g., body acceptance), rather than weight loss, fostered positive effects from positive appearance-related commentary. Study 3 determined whether information provided about a female target’s weight trajectory and/or body image altered the participants’ impression of that target. The target described as on a weight loss trajectory compared to a weight gain trajectory was rated more favourably on certain personality and physical characteristics. Further, the target described as having a positive body image (including high self-esteem) compared to a target described as having a negative body image (including low self-esteem) was also rated more favourably on numerous personality and physical characteristics. All three studies demonstrated the value of having a positive body image both from an intrapersonal and interpersonal perspective. This has important implications for future research and body image programs designed to foster positive body image.
    • Influence of upper limb ischaemia-reperfusion injury on the regulation of cutaneous blood flow during local thermal hyperaemia

      McGarr, Gregory Walter; Applied Health Sciences Program
      The present research was developed to investigate the effects of acute upper limb ischaemia- reperfusion (I-R) on neurovascular and endothelial control of the cutaneous micro-circulation in the forearm and finger by evaluating its influence on the magnitude and kinetics of the vasodilatory response to local skin heating. Study 1 investigated between-day reliability of the local heating response in non-glabrous and glabrous index finger skin. Study 2 investigated the effects of I-R on the local heating response in non-glabrous and glabrous skin of the index finger. Study 3 investigated within- and between-day reliability of the local heating response in non-glabrous forearm skin. Study 4 investigated the effects of I-R on the local heating response in non-glabrous forearm skin, as well as the contribution of sensory nerves in mediating the magnitude and kinetics of this response. When data were normalized for blood pressure and expressed as cutaneous vascular conductance (CVC) reliability was generally comparable across all skin sites. In non-glabrous skin reliability was superior when CVC was normalized to maximum heating. At all skin sites, normalizing CVC to baseline produced poor results. Vasodilatory onset time and time to initial peak during local heating produced moderate to good reliability for all skin sites in Studies 1 and 3. In the finger, I-R did not influence the magnitude of the local heating response for the initial peak or plateau phases in either skin type. However, I-R did cause a ~23% delay in vasodilatory onset time and a ~16% delay in time to initial peak in non-glabrous skin. In the forearm, I-R attenuated the initial peak and plateau phases by ~31% and ~34%, respectively. Vasodilatory onset time was also delayed by 34% post-ischaemia. The contribution of sensory nerves in mediating the initial peak and vasodilatory onset time were significantly reduced post-ischaemia, while sensory nerves did not influence the plateau. It is concluded that upper limb I-R impairs the local heating response in non-glabrous forearm and index finger skin. A combination of cutaneous sensory nerve impairment and reduced nitric oxide bioavailability appear to be responsible for attenuating the vasodilatory response to local skin heating under these conditions.
    • Cardiac Autonomic Assessment and Diastolic Function in Individuals with Spinal Cord Injury

      Sharif, Hisham; Applied Health Sciences Program
      The primary purpose of this thesis was to examine the validity and reproducibility of the QT-variability index (QTVI) as a measure of cardiac autonomic function in individuals with spinal cord injury (SCI). The secondary purpose was to investigate the influence of cardiac autonomic activity and blood volume on diastolic function in individuals with SCI. Results from Study 1 showed that the QTVI increased when participants performed a cardiovascular (CV) stress maneuver, and subsequently returned to baseline after blocking sympathetic outflow via metoprolol. Moreover, while participants were resting, the QTVI increased after blocking parasympathetic activity via atropine. These results suggest that the QTVI may reflect both cardiac sympathetic and parasympathetic activity in those with incomplete SCI, depending on the autonomic state of the individual. Results from Study 2 demonstrate high day-to-day reproducibility of the QTVI in participants with SCI, regardless of injury level, and also in those with high level injuries who may have reduced cardiac sympathetic regulation. Results from Study 3 showed that indices of cardiac parasympathetic activity (HRV and QTVI) were correlated with left ventricular filling in able-bodied individuals but not in individuals with SCI, suggesting a disconnect between cardiac parasympathetic activity and diastolic function after SCI. In addition, for the able-bodied group, the cold face test (CFT) increased vagal activity which was associated with bradycardia and augmentation of diastolic filling. However, for the SCI group, the increase in vagal activity during the CFT was associated with no change in heart rate and an attenuation of diastolic function. Results from Study 4 showed that although individuals with SCI were hypovolemic, resting diastolic velocities were similar compared to the able-bodied group. This maintenance of diastolic function appeared to be attributed to the cardiac atrophy that manifests following SCI. In addition, there was no between-group difference in the diastolic response to rapid saline infusion. Findings from this dissertation suggest that the QTVI is a valid and reliable tool for non-invasively estimating cardiac autonomic regulation in individuals with SCI. In addition, although the mechanical aspect of diastolic function is preserved after SCI, atypical vagal-diastolic interactions may impair ventricular filling in this population.