Life Sciences Commons^™

Impact Of Extremely Low-Frequency Magnetic And Electric Stimuli On Vestibular-Driven Outcomes, Nicolas Bouisset

Electronic Thesis and Dissertation Repository

The vestibular system is extremely sensitive to electric fields (E-fields). Indeed, vestibular hair cells are graded potential cells and this property makes them very susceptible to small membrane potential modulations. Studies show that extremely low-frequency magnetic fields (ELF-MF) induced E-fields impact postural control in which the vestibular system plays an important role. However, the knowledge of whether this is indeed a vestibular specific effect is still pending.

Considering its crucial role and the specific neurophysiological characteristics of its hair cells, the vestibular system emerges as an ELF-MF likely target

The three studies presented in this thesis aimed to further address …

Perspectives Of Canadian University Coaches On Integrating Sport Psychology And Mental Performance Consultants In Varsity Programs, Federico Cisneros Sánchez

Electronic Thesis and Dissertation Repository

Recently, sport psychology has become a more popular resource for athletes and coaches when looking to increase performance. It is unknown how many Canadian universities utilize sport psychology services in their athletic programs. Semi-structured interviews were conducted with coaches of Canadian university varsity teams to learn about their opinions on sport psychology and mental performance consultants (MPCs). The research was approached from a pragmatic perspective. Results showed that MPCs are important to enhance performance and provide mental health resources. MPCs provide athletes with personal and leadership development, mental skills training, and mental health support. MPCs can also be a resource …

The Impact Of Impacts: Repetitive Head Impact Exposure In Canadian University Football Players, Jeffrey S. Brooks

Electronic Thesis and Dissertation Repository

Due to the physical nature of the game and repeated head impacts between players each play, the sport of football has one of the highest incidence rates of concussion. With nearly two million participants, this incidence rate translates to a reserved estimate of 100,000 concussions per year due to the contact nature of the sport. Injury thresholds have proven difficult to establish, so American football concussion research has shifted focus to measuring the accumulation of repetitive head impacts. As there are numerous rule differences between Canadian and American football, head impact exposure may present differently for Canadian players. Accordingly, the …

Understanding Physical Activity Behaviour In Ontario, Canada: A Cross-Sectional Cohort Analysis Of Carrot Rewards App Users, David D. Mchugh

Electronic Thesis and Dissertation Repository

Little device-measured data are available to describe the physical activity (PA) of rural-dwelling individuals living with chronic disease. PURPOSE: From accelerometer data collected using a smartphone app (‘Carrot Rewards’), we sought to provide mean daily step counts for app users in general and by age and gender for those living in rural/urban areas and those self-reporting a chronic disease or not. METHODS: This cross-sectional cohort study used device-assessed data from Ontario app users (i.e., PA data collected over a 7-day period for each user) who completed an in-app chronic disease survey from December 2018 to April 2019. A …

Quantifying The Inter-Relationships Amongst Muscle Blood Flow, O2 Uptake And Muscle Deoxygenation Kinetics From Elevated Baseline Metabolic Rates And Increasing Work Rate Amplitudes, Lorenzo Love

Electronic Thesis and Dissertation Repository

Upon an instantaneous increase in work rate (WR), pulmonary O₂ uptake (V̇O_2p) increases in an exponential-like manner towards a new steady-state. To support this increase in V̇O_2p there is an increase in blood flow (BF; O₂ delivery) to the muscle. Previous research has shown that the rate of this increase in V̇O_2p (which defines V̇O_2p kinetics) becomes progressively slower with increasing baseline WR (WR_bl). Given the paucity of research on blood flow dynamics and underlying muscle metabolic rate, this thesis examined the effect of metabolic rate on the dynamics and relationships …

Leadership-As-Disciplinary Stewardship: A Social Movement For Kinesiology’S Future Success In The 21st Century University, Jenna R. Lorusso

Electronic Thesis and Dissertation Repository

Some scholars in kinesiology have advocated for the adoption of the leadership-as-disciplinary stewardship (LDS) construct as a way for the discipline to survive and thrive in the challenging 21^st Century university climate. Despite budding interest in LDS, there is a lack of empirical research on the construct and the limited conceptual literature lacks the specificity, practicality, and transformative quality necessary for realistic and fruitful application. This participatory research, informed by the social movement theory of collective action frames, investigated the meaning, need, development, and motivation of LDS in kinesiology by engaging 10 senior scholars from various countries and sub-disciplinary …

The Effects Of Medial Gastrocnemius Muscle Fatigue On Regional Modulation Of The Ankle Plantarflexors During Standing External Perturbations, Nicole D. Grzywnowicz

Electronic Thesis and Dissertation Repository

The ankle plantarflexor muscles (soleus, medial, and lateral gastrocnemius) exhibit direction-specific regional modulation of muscle activity during external perturbations. This study sought to investigate the effect of medial gastrocnemius muscle fatigue on plantarflexor muscle activation patterns. Unipedal balance was tested during external perturbations that challenged standing balance in different directions before and after low-frequency fatigue was induced to the medial gastrocnemius via electrical stimulation. High-density surface electromyography was used to determine the amplitude and barycenter of muscle activation. It was hypothesized that the central nervous system would compensate for a loss of force-generating capacity in the medial gastrocnemius by modulating …

Effect Of Ankle Joint Position On Triceps Surae Contractile Properties And Motor Unit Discharge Rates, Kalter Hali

Electronic Thesis and Dissertation Repository

The length-tension relationship of the triceps surae (TS) can be altered by changing the knee joint position, ankle joint position or both. However, studies exploring the effect of muscle length on triceps surae (TS) neuromuscular properties have focused only on changes in knee joint position, affecting only two of the three muscle components of the TS. Thus, the purpose of this study is to compare the neuromuscular properties of the three TS muscles during plantar flexion contractions at two ankle joint positions, 20° dorsiflexed (DF) and 20° plantar flexed (PF). Maximal isometric voluntary strength (MVC), voluntary activation, and evoked contractile …

Effects Of A Pregnancy Lifestyle Intervention On Emotion Regulation In Infants Responding To A Toy Removal Task At One-Year Of Age, Mollie Manley

Electronic Thesis and Dissertation Repository

Poor infant emotion regulation (ER) has been linked with increased psychopathological risk in infancy and childhood. The Developmental Origins of Health and Disease Hypothesis suggests the prenatal period as the earliest point of intervention, where fetal exposure to healthy lifestyle changes can promote optimal ER in infancy. Infant electroencephalography (EEG; n=13) and heart rate variability (HRV; n=18) were measured at rest and in response to a toy removal task, to determine the ER of infants whose mothers participated in a nutrition and exercise intervention during pregnancy. Results demonstrated positive left frontal alpha asymmetry at rest (0.08± 0.66) and in response …

Assessment Of Intrinsic Hand Neuromuscular Physiology, Philemon Tsang

Electronic Thesis and Dissertation Repository

Alterations to the peripheral nervous system and neuromuscular physiology may impact hand function in a typical or clinical population, such as individuals with ulnar neuropathy. The mechanisms that influence these positive and negative changes are still not well understood. The three studies within my thesis aim to validate the reliability of decomposition-based quantitative electromyography (DQEMG) measurements and explore the changes in intrinsic hand neuromuscular physiology in a typical aging population and individuals recovering from a surgical intervention for severe ulnar neuropathy.

The purpose of the first study was to determine the test-retest reliability of near-fibre (NF) jiggle, a measure of …

Comparison Of Whole-Body Vibration Attenuation Properties Between Active And Passive Suspension Seats, Ben Dietze

Electronic Thesis and Dissertation Repository

Professional drivers are at a high risk of WBV injury as they are exposed to vibration constantly throughout a working day. Recently a company has attempted to mitigate the risk by developing an active suspension seat aimed at reducing WBV exposure for long haul truck drivers. The purpose of this thesis was to compare the new active suspension technology to the current industry standard passive suspension seat. Seats were tested with Random vibration exposures and exposures simulating Canadian long-haul trucks. Seats were evaluated by A(8) daily vibration exposure and peak transmissibility metrics. The results determined that the active suspension is …

Oculomotor Task-Switching Performance Improves And Persists Following A Single Bout Of Aerobic Exercise, Diksha Shukla

Electronic Thesis and Dissertation Repository

Executive function includes the core components of response inhibition, working memory, and cognitive flexibility. Interestingly, an accumulating evidence has reported that inhibitory control and working memory improve following a single bout of exercise. It is, however, largely unclear whether cognitive flexibility elicits a similar post-exercise benefit. Accordingly, Chapter Two of my thesis examined whether 20-min of aerobic exercise provides an immediate post-exercise ‘boost’ to cognitive flexibility. Chapter Three examined for how long a putative post-exercise benefit persists. Cognitive flexibility was examined via an AABB task-switching paradigm wherein participants alternated between a well-practiced and a novel oculomotor task pre- and post-exercise. …

The Use Of Humor In Intercollegiate Varsity Sport, Charles R S Fitzsimmons

Electronic Thesis and Dissertation Repository

Three separate studies examined the use of humor in intercollegiate varsity sport. The first explored, via focus groups, who, what, where, when, and why humor is used. The second examined, via multilevel modeling, how athletes’ perceptions of cohesion (measured via the Group Environment Questionnaire; Carron et al., 1985) related to the styles of humor (measured via a modified version of the Martin et al. (2003) Humor Styles Questionnaire), used by athletes, teams, and head coaches. The third investigated, via multilevel modeling, how the styles of humor used by athletes and head coaches related to athletes’ liking of the head coach, …