Life Sciences Commons^™

Head Impact Exposures In Youth Canadian Football Players Aged 12-14 Do Not Significantly Impair Antisaccade Performance, William J. Smith

Electronic Thesis and Dissertation Repository

There is a growing body of research evaluating head impacts in sport, but studies have not evaluated youth football in Canada. It is important to evaluate football in Canada as the rules and field size are different than American football, and this may influence the impact exposures. The purpose of this study was to quantify the head impact exposures in youth Canadian football and determine if a season’s worth of impacts could cause impairments in executive function. Players (n=50) had their head impacts recorded using an impact measuring device (GForceTracker) throughout all contact practices and games. A subset of players …

True North Strong Canada 150: Canadian Identity And Its Contribution To Doping Free Sport, Helena A. Hlas

Electronic Thesis and Dissertation Repository

This thesis, a reflective piece inspired by “Canada 150” events, explores the psychosocial and sociocultural factors surrounding the ongoing evolution of the clean sport movement in Canada. A literature review recounts the critical events in the history of doping, viz. the Ben Johnson scandal, which resulted in a call to overhaul sport culture and realign it with fair play values. Theories in sports philosophy and psychology provide a further understanding of the meaning of sport, and psychosocial factors that are inextricably linked to doping behavior, respectively. The autoethnographic method provides insight into current Canadian values to compare with those in …

Magnetic Field Frequency-Response For Human Magnetophosphene Perception And Associated Eeg Modulations, Cadence M. Baker

Electronic Thesis and Dissertation Repository

Background: Magnetophosphenes are among the most reliably reported effects resulting from magnetic induction. The frequency dependence of the perception threshold is crucial, as guideline agencies use this information to set exposure limits whose purpose is to protect public and workers.

Objective:Establish the magnetophosphene perception thresholds throughout the extremely low frequency range (0-300 Hz) and evaluate the use of EEG as a biomarker.

Hypothesis:Perception thresholds will be lowest at ~30 Hz. EEG occipital alpha power will decrease upon perception.

Methods:60 participants were exposed to homogenous magnetic fields up to 300 Hz, and 70 mT. EEG alpha power …

Cardiodynamic Associations With Resilience In Undergraduate Students And The Effect Of A Mentorship Intervention, Rachel J. Knetsch

Electronic Thesis and Dissertation Repository

The National College Health Assessment (NCHA) indicates that a majority of Canadian university students report feeling overwhelmed, stressed, and anxious during their undergraduate studies. Resilience refers to positive adaptation, or the ability to maintain or regain mental health, despite experiencing adversity (Herrman et al., 2011). While autonomic indices have been used to describe chronic physiological stress, the role of heart rate variability (HRV) as an index of resilience remains unclear. This research tested the hypotheses that (1) there is a relationship between HRV and resilience scoresand (2) a mentorship intervention will improve HRV and resilience outcomes. Fifty-seven first year students …

Operant Conditioning Of Human Upper-Limb Stretch Reflexes, Ehsan Abolhasani

Electronic Thesis and Dissertation Repository

Operant conditioning of short-latency reflex (SLR) and H-reflex have been investigated in animals and humans. We modified previously established protocols for conditioning lower limb H-reflexes to up-condition the SLR in brachioradialis muscle and to investigate the effect of such conditioning on the long-latency response (LLR) of synergistic muscles. Our study included 12 healthy participants. Each participant took part in 3 baseline and 27 conditioning sessions in 6 weeks, followed by two additional sessions one month and two months after the last conditioning session. We found an increase in SLR magnitude in 50% of participants (by 15%±2.50). However, there was no …

Performance Impact Of Different Lower-Limb Setup Positions In The Backstroke Swimming Start, Gordon E. Barkwell

Electronic Thesis and Dissertation Repository

The performance impact of different knee extension angles in the setup position for a backstroke start was evaluated using an instrumented starting surface. Ten backstroke swimmers completed maximum-effort starts in each of two setup positions: one with the knees flexed, and one with the knees extended. The start handles and touchpad were instrumented with tri-axial force plates. Activity of major hip and knee extensors was measured using surface electromyography. Body position was recorded throughout the start using two high-speed cameras. There was no difference in time to 10 m between the two conditions, indicating there is likely no advantage in …

Motor Variability In Rowing, Maude Potvin-Gilbert

Electronic Thesis and Dissertation Repository

The aim of the study was to analyze the impact of environment, intensity and distance rowed on temporal variability of strokes and on knee angle variability. 11 participants rowed 2,000 m at high and low intensities on an ergometer and at high intensity in a single on-water. Data were collected at the beginning and at the end of each exercise. All the factors influenced significantly the temporal variability (respectively beta=-0.013 and p .007=; beta= 0.007 and p=.021; beta=0.06 and p=.028). The difference of visual information and the need of the rower to adapt to environmental factors might explain …

Pilot Study: Heart Rate Variability Analysis And Mental Health Outcomes In University Female Hockey Players, Kaitlyn Jacobs

Electronic Thesis and Dissertation Repository

Exercise improves anxiety and depression, both of which are associated with impaired autonomic regulation of heart rate (HR). In turn, HR variability (HRV) is a reliable physiological indicator of external stressors. The following research tested the hypothesis that HRV is indicative of chronic resilience towards mental stress in female varsity hockey players. Seventeen varsity hockey players (HOCK, age 21 ± 1.5) and fifteen healthy controls (CTRL, age 21 ± 2.2) at Western University participated three times throughout a 7-month season. Participants completed questionnaires (brief resilience scale, BRS; generalized anxiety scale, GAD-7; mental health inventory, MHI; visual analog scale, VAS; short …

Working Memory And Falls Risk In Older Adults: An Event-Related Potential Study, Yee (Michelle) S. Wong

Electronic Thesis and Dissertation Repository

BACKGROUND: The aging population is rapidly increasing, where currently in North America, the population of older adults (ages 60+) outnumbers the population of children. Falls are a major concern for older adults and their quality of life. Cognitive impairment has been shown to be declined in older adults at-risk for falls, but working memory has not been thoroughly investigated within this population. PURPOSE: To examine differences in Non-Fallers, Moderate Risk for Falls, and Fallers in a working memory task using electroencephalography (EEG). METHODS: Older adults (n=44, female=27) aged 60 – 80 years (m=68.8, SD=4.7) completed two sessions. The first session …

“And, Needless To Say, I Was Athletic, Too:” Southern Ontario Black Women And Sport (1920s – 1940s), Ornella Nzindukiyimana

Electronic Thesis and Dissertation Repository

This dissertation presents a two-part study of sporting practices of Southern Ontario Black women, between the 1920s and the 1940s, aimed at developing a socio-cultural history of sport that includes narratives from marginalized groups. Given sport’s traditional position as a masculine domain, as well as Canada’s status as a patriarchal White supremacy, the accounts presented in this work centre Black women’s sport experiences through an intersectional perspective. It is argued that, by virtue of their simultaneously racialized and gendered identities, Black women had distinct sporting experiences from those of White women and men and Black men.

The first study used …

Participatory Action Research Examining The Role Of Physical Activity In Mentoring For Resilience, Francesca Gable

Electronic Thesis and Dissertation Repository

This study examined the use of physical activity-based mentorship programs to positively influence student mental health and resilience in post-secondary institutions. The process of relationship building was observed through regularly implemented physical activity interactions over time. The purpose was to determine the ability of a physical activity-based mentorship relationship to positively influence student resilience. A participatory action research methodology was used to engage with a population of ninety undergraduate Kinesiology students (30 mentors:60 protégés) over an eight-month period. Sixty interviews and thirteen focus groups were conducted, and fifteen-hundred pages of journal reflections were consulted to further understand the relationship building …

The Acute Effects Of Nicotine And Exercise On Working Memory In Smokers, Matthew Fagan

Electronic Thesis and Dissertation Repository

Background: In a non-smoking population exercise and nicotine have been shown to increase cognition (Guirguis, 2016). In non-deprived smoking model it is unknown if the exercise will provide the same benefit seen in non-smokers.

Methods: A randomized counterbalanced crossover study design was utilized. The primary outcome was working memory accuracy and reaction time measured by n-back assessments (i.e., 3-back).

Results: A repeated measure ANOVA revealed a significant treatment effect for accuracy on the 3-back [F (24) = 8.118, p=.002, n²=.404]. Post-hoc paired sample t-tests uncovered a significant improvement in accuracy from baseline and the …

Functional Anatomy Of Palmar Musculature, Colin W. Moore

Electronic Thesis and Dissertation Repository

The palmaris longus (PL) and palmaris brevis (PB) are upper limb muscles considered atavistic remnants of those found in animal species. Despite their use in surgical grafting and tendon transfer procedures, the functional role of the PL and PB have not been investigated comprehensively in vivo. Using a multi-modal experimental approach consisting of indwelling fine wire electromyography (EMG), ultrasonography and immunohistochemical muscle staining techniques, the function of the PL and PB in the hand was evaluated both in in vivo and in situ.

The purpose of Study 1 was to determine whether the PL provides synergistic contributions to …