Kinesiology
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Item Gender Effects on Knee Loading and Prediction of Knee Loads Using Instrumented Insoles and Machine Learning(2024) Snyder, Samantha Jane; Miller, Ross H.; Shim, Jae Kun; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Women are more likely to experience knee osteoarthritis as compared to men, but the underlying mechanisms behind this disparity are unclear. Greater knee loads, knee adduction moment, knee flexion moment, and medial joint contact force, are linked to severity and progression of knee osteoarthritis. However, it is unknown if greater knee loads in healthy, young women during activities of daily living (sit-to-stand, stand-to-sit, walking and running) can partially explain the higher prevalence of knee osteoarthritis rates in women. Although previous research showed no significant differences in peak knee adduction moment and knee flexion moment between men and women, differences in peak medial joint contact force are largely unexplored. Women also tend to take shorter steps and run slower than men. It is unknown if these differences may result in greater cumulative knee loading per unit distance traveled as compared to men. Furthermore, knee loading measurement is typically confined to a gait laboratory, yet the knee is subjected to large cyclical loads throughout daily life. The combination of machine learning techniques and wearable sensors has been shown to improve accessibility of biomechanical measurements without compromising accuracy. Therefore, the goal of this dissertation is to develop a framework for measuring these risk factors using machine learning and novel instrumented insoles, and to investigate differences in peak and cumulative per unit distance traveled knee loads between young, healthy men and women. In study 1 we developed instrumented insoles and examined insole reliability and validity. In study 2, we estimated knee loads for most activities with strong correlation coefficients and low to moderate mean absolute errors. In study 3, we found peak medial joint contact force was not significantly different across activities for men and women. Similarly, in study 4, we found no significant difference between men and women in knee loads per unit distance traveled during walking and running. These findings suggest biomechanical mechanisms alone cannot explain the disproportionate rate of knee osteoarthritis in women. However, in future research, the developed knee loading prediction models can help quantify daily knee loads and aid in reducing knee osteoarthritis risk in both men and women.Item P(L)AYING FOR THE FUTURE: THE COALESCING OF YOUTH, SPORT, AND COMMUNITY DEVELOPMENT IN CHARM CITY(2024) Stone, Eric Alexander; Andrews, David L; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This project explores how Sport-Based Youth Development (SBYD) has been arrived at as an ideal vehicle for youth development in contemporary Baltimore. To understand the SBYD approach, the project seeks to explore four interrelated empirically grounded sites/questions that explain why sport is expected to help develop, discipline, and prepare youth and communities for the future. Three key themes emerged from this work: 1) that youth must be problematized by different ideas, beliefs, and discourses to make them ‘amenable’ to being targets of SBYD; 2) that organizations are pushed into competing with one another rather than collaborating due to the need of the state to maintain control of how youth are incorporated into society; and 3) that various tools and techniques are used through the vehicle of sport to inculcate specific values into underserved youth and their communities. The first chapter identifies two of the key theoretical positions/approaches that inform the project: Governmentality and Articulation as theory/method. The second chapter provides an overview of how scholars have examined the phenomenon of Sport for Development and Peace as a historical, methodological, and empirical site. The third chapter identifies the methods and methodologies that underpin the project. The fourth chapter provides a brief reflexive overview of how I arrived in Baltimore to conduct the project. The fifth chapter seeks to (explore) how Baltimore’s underserved citizens have been positioned as targets of SBYD as conceived of by politicians, providers, public servants, and citizens of the city, state, and nation. The project found that SBYD in Baltimore is a product of specific policies, processes, decisions, ideologies, and discourses that conspire to create a specific understanding of youth and communities as ripe for and requiring intervention through sport and other recreational pursuits to reform their behavior and orientation towards neoliberal social values that has evolved over the last fifty years. The sixth chapter examines/explicates how discourses of youth, their future, and the role of sport are used by three SBYD organizations to connect with potential participants, to obtain resources and funding, and to report on their activities and programming to measure the impact on the targeted community. The project found that underserved youth and communities are subjectivated by discourses of responsibility, deficiency, the unknown future, and the perceived American values of neoliberal meritocracy. These discourses were conveyed by programs via their websites, curricula, tax documents, and other forms of media to funders, participants and other valueholders. The seventh chapter identifies how organizations make use of formal and informal relationships to support the implementation of programming, to obtain funding, and to support organizations as they seek to legitimize their operations and activities in the eyes of valueholders. The project found that the use of formal and informal relationships by valueholders and organizations enables SBYD providers to secure access to funding, space, and capacity to support program initiatives. The eighth chapter seeks to engage with the beliefs, perspectives, and values of SBYD providers and valueholders to understand how these personal ideas and views shape the implementation of SBYD in Baltimore by speaking to the staff of three organizations operating within the city. The project found that the production of SBYD programming is facilitated and challenged by perceptions of the youth and community, ideas about the purpose and value of sport, and a broader rooting of ideas about youth and communities in urban stereotypes. By examining these four sites/questions, the project identifies how SBYD is assembled into a disciplining, educating, rationalizing tool to create productive youth for the future. The project ends by identifying new areas of research such as education initiatives for volunteers to contextualize the communities they work in, challenges and limitations such as completing research during the COVID-19 Pandemic, and key takeaways such as connecting with youth to move away from abstract stereotypes of urban life.Item THE INFLUENCE OF CUMULATIVE SLEEP RESTRICTION ON HUMAN PERFORMANCE: EXAMINATION OF BRAIN DYNAMICS AND SUSTAINED ATTENTION(2024) Kahl, Steven; Hatfield, Bradley; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Sustained attention (SA) impacts nearly every aspect of human performance. From the exactness of performing brain surgery to safely driving from one location to another, the ability to concentrate on a task for a period of time is important for success in work, school, relationships, and individual activities. As a key component of executive function (EF) and psychomotor performance, SA can be affected by many mental and physical processes. One process that can impact SA is restricted sleep, which is becoming more relevant in our ever-evolving technological society. Numerous studies have examined the impact of short bouts of restricted sleep on response time, a measure of SA, but few studies have examined the impact of the accumulating effect of sleep restriction (SR) on response time and brain dynamics as measured with electroencephalography (EEG). As part of a larger 40-day study, eight healthy participants (five female, average age 27.75) were observed for seven consecutive days and nights in a sleep lab, where they spent five hours in bed per night and engaged in numerous psychomotor vigilance tests (PVT), an indicator of SA, as part of their daytime activities. Through multiple one-factor ANOVAs, response time significantly slowed, and brain dynamic changes occurred, measured by slow wave activity (SWA) maxima change in the Fz electrode, located in the midline frontal region, over the course of the entire week of continual SR compared to an extended sleep night. Employing mixed method effects revealed a statistically significant relationship between response time and SWA maxima differences. The data show that not only does response time increase the day after rising first and last SWA maxima levels converge (i.e., flattening of the line slope connecting these values) caused by short bouts of SR, but these phenomena continue this progression with prolonged SR. Over the course of the week-long SR, the final SWA maximum increased at a higher rate than the first SWA maximum, leading to the maxima difference shrinking as response time increases. These findings indicate that brain dynamics highlight less restorative sleep occurring alongside a lack of sustained attention when sleep is restricted on a consistent basis.Item THE RELATIONSHIP OF PERCEIVED WORKLOAD AND PSYCHOMOTOR PERFORMANCE TO BRAIN DYNAMICS DURING VARYING DEGREES OF TASK DEMAND AND CONTROLLABILITY IN A FLIGHT-RELATED COMPENSATORY TRACKING TASK(2024) Pietro, Kyle; Hatfield, Bradley D.; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The assessment and prediction of cognitive-motor performance holds great importance for any discipline connected to human operators in the context of safety-critical behavior. A study of mental workload is essential to understanding the intrinsic limitations of the human information processing system, and the resultant cognitive-motor behavior. Mental workload and the quality of cognitive-motor performance are generally known to be impacted by task demand. However, one feature of task demand far less understood is the controllability of a system (e.g. the responsiveness of a flight platform and its handling qualities). In the realm of Human-Machine Interface, the assessment of system controllability has typically been conducted through subjective measurements, such as the Cooper-Harper Rating Scale, a widely used metric in aircraft design to measure perceived operator workload and handling qualities, first proposed in 1969. A fundamental element of the decision making process for handling qualities associated with operator workload includes the reporting of the control compensation required to overcome deficiencies and errors that could impact and inhibit the successful completion of a task. Yet, the Cooper-Harper Rating Scale, and all other subjective rating scales are limited by a lack of objectivity, reliability, reduced sensitivity to dynamic changes in operator workload, and, are solely dependent on subjective estimates of effort to control compensation within a system, despite such wide usage in the field. To overcome such limitations, the contribution of this dissertation is the estimation of perceived operator workload, based on objective brain dynamics captured during varying levels of task demand and controllability. Therefore, the objective of this dissertation was to ascertain how objective brain dynamics and subjective ratings would respond to flight-related compensatory tracking tasks when handling qualities and task demand are manipulated. More specifically, this dissertation assessed the relationship between objective brain dynamics and subjective rating scales explicitly related to mental workload, as reported during compensatory tracking tasks of varying complexity, while also challenged with progressively increasing levels of controllability (i.e., levels of handling qualities). Thus, Aim 1 was to assess the effects of varying levels of handling qualities (i.e., HQR1, HQR2, HQR3) on mental workload and psychomotor performance. Aim 2 was to investigate the effects of increased task demand (i.e., Single-axis vs. Multi-axis) on mental workload and psychomotor performance. Finally, Aim 3 was to examine the empirical relationship between objective brain dynamics and subjective ratings of workload. Accordingly, this dissertation employed a 2 Condition (Single-axis vs. Multi-axis) x 3 Level of Handling Qualities (HQR1, HQR2, HQR3) design. Perceived workload, psychomotor performance, and brain dynamics, derived from EEG power spectra and spectro-temporal analyses, were assessed in twenty-two volunteer participants in the Naval Reserve Officers’ Training Corps. Overall, the findings of this dissertation support a characterization of the human information processing system as a finite resource with a limited capacity. When challenged with increasing levels of handling qualities, parietal alpha power decreased, behavioral performance was significantly attenuated, and subjective ratings of workload were higher, as was expected. Accordingly, there was a significant relationship between objective brain dynamics and subjective ratings of workload. Furthermore, an exploratory wavelet-based analysis revealed some generally high cross-correlations between brain dynamics and psychomotor performance, which may inform future research efforts of more dynamic measurement strategies to capture perceived workload with increased fidelity. Therefore, the results of this dissertation underscore the usage of objective brain dynamics to supplement subjective rating scales, which can provide additional insights to enhance our understanding of brain and motor coordination under varying levels of task demand and system handling qualities.Item THE EFFECTS OF AGE, SARCOPENIA, AND RESISTANCE EXERCISE TRAINING ON MITOCHONDRIAL STRUCTURAL DYNAMICS IN SKELETAL MUSCLE(2024) Sapp, Catherine; Prior, Steven J; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Sarcopenia, the progressive, age-related loss of skeletal muscle mass, contributes to older adults’ risk of falls, hospitalization, and loss of independence. Mitochondrial dysfunction is a hallmark trait of aging and sarcopenia that may be mediated by changes to mitochondrial structure and location through the involvement of mitochondrial fusion, fission, and mitophagy (collectively referred to as mitochondrial quality control). Therefore, the purpose of this dissertation was to investigate whether mitochondrial quality control is altered by age or sarcopenia. The first study performed in a rat model of aging demonstrated that expression of proteins regulating fusion and mitophagy was higher in skeletal and cardiac muscle from old vs. young rats, and this was accompanied by reduced expression of fission proteins in skeletal muscle in the old rats. The second study included older humans and revealed no differences in mitochondrial quality control protein expression in skeletal muscle from sarcopenic vs. non-sarcopenic older adults. Furthermore, twelve weeks of resistance exercise training did not alter the expression of mitochondrial quality control proteins in the sarcopenic individuals. The third study investigated morphological differences in mitochondrial subpopulations and lipid droplets from the sarcopenic individuals from study two, both before and after resistance exercise training. Peripherally located and intermyofibrillar mitochondrial content and morphology did not change significantly after resistance exercise training. Lipid droplets from the intermyofibrillar region were similarly unchanged, but lipid droplets from the peripheral region had minor morphological changes after resistance exercise training. Together, this dissertation indicates that mitochondrial quality control proteins in skeletal and cardiac muscle are altered in response to aging and may contribute to mitochondrial dysfunction, but mitochondrial structural dynamics in skeletal muscle do not appear to be altered in older adults with a moderate degree of sarcopenia. This suggests that other, non-mitochondrial factors may play larger roles in the pathophysiology of sarcopenia. While the sarcopenic participants did improve muscular strength after resistance training, this was not accompanied by changes in mitochondrial content, morphology, or quality control. Therefore, resistance exercise training may not be an effective strategy to enhance mitochondrial structural dynamics in sarcopenia.Item HIPPOCAMPAL GLUCOSE TRANSPORT AND OXIDATION IN RESPONSE TO DISRUPTED BLOOD FLOW IN AN AGING RAT MODEL OF HEART FAILURE(2023) Pena, Gabriel Santiago; Smith, J. Carson; Kuzmiak-Glancy, Sarah; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The primary objective of this dissertation was to investigate, in a rodent model of cardiovascular disease promoted by transverse aortic constriction (TAC), whether cerebral hypoperfusion stemming from chronic high pulsatile blood flow, and cerebral hypoperfusion stemming from low cerebral blood flow differentially affected hippocampal glucose transport and hippocampal mitochondrial function. We first, characterized the changes in right and left carotid hemodynamics and diameter in response to TAC and in a SHAM control group at three different time points (20-, 30-, and 40 weeks) post-surgery. Then, right, and left hippocampal mitochondrial content and substrate oxidation were investigated, and protein expression of glucose transporters and mitochondrial quality control markers were quantified. In this study, both the SHAM and TAC conditions included male and female rats to address possible sex differences. We report that all time points within TAC, right carotid blood flow velocities and pulsatility were greater than the left, but did not worsen over time. No differences in mitochondrial content were found within TAC nor between TAC and SHAM, but within TAC animals there were impairments in right hippocampal coupled and uncoupled respiration when compared to the left. When compared to the SHAM controls, right and left hippocampi of TAC animals had higher protein expression of mitochondrial quality control markers, but no differences in glucose transporter expression were found. Thus, while both high blood flow and/or pulsatility as well as low cerebral blood flow may lead to brain hypoperfusion, the metabolic consequences of the two may not be the same. The results from this dissertation contribute to the expanding literature characterizing the intersection between cardiovascular disease and neurodegeneration.Item ALLOSTATIC LOAD INFLUENCES VASCULAR FUNCTION AND SYMPATHOLYSIS IN YOUNG BLACK ADULTS(2024) Eagan, Lauren Elizabeth; Ranadive, Sushant M; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In the U.S., Black individuals tend to face a disproportionately higher risk for hypertension. This is largely attributed to chronic sympathetic activation induced by heightened exposure to psychosocial stressors. Allostatic load (AL), an index of cumulative physiological dysfunction from chronic stress, is associated with hypertensive risk and is also heightened in Black adults compared to those of other racial groups. Indeed, increased sympathetic activity is a hallmark characteristic of both hypertension and AL. The inability to blunt sympathetic-induced vasoconstriction during exercise (impaired functional sympatholysis) is also associated with hypertension. This dissertation aimed to investigate whether AL was associated with measures of vascular health in young Black adults, both at rest and during a sympathetic stressor. In our first study, we examined associations between AL and indices of vascular function and structure among young Black adults at rest, finding that higher AL was associated with greater macrovascular dysfunction and amplified wave-reflections. Additionally, we identified significant correlations among greater self-perceived stress with smaller brachial artery diameters and greater wave-reflections. The second aim of this dissertation focused on the associations between AL and the magnitude of functional sympatholysis among this population. Results indicated a positive association between AL and functional sympatholysis, with amplified sympatholytic responses among young Black females, as compared to their male counterparts, when forearm volume was controlled for. Overall, our findings suggest that elevated AL might predict macrovascular dysfunction at rest, with larger arterial diameters potentially compensating for chronic stress. These adaptive mechanisms, commonly observed in aging and diseased states, may also explain the positive correlations between AL and the functional sympatholytic response in young Black adults. Our consistent observations of the redundant vascular mechanisms among young Black adults allowing for adaptation to chronic stress strengthen our findings and further highlight the complex interplay between stress and cardiovascular health in Black adults.Item Sport, Race, and Grassroots Activism: A Contextual Analysis of Colin Kaepernick's Know Your Rights Camp as a Sporting Social Movement Organization(2024) Wallace, Brandon T.; Andrews, David L.; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation engages Know Your Rights Camp for Black Liberation (KYRC) – founded and led by athlete-activist Colin Kaepernick – as a case study for critically analyzing the contemporary intersections of sport, race, and grassroots activism. Among other related initiatives, KYRC hosts “camps” across the U.S. designed to facilitate empowerment, solidarity, and critical education about structural racism for Black and Brown youth in marginalized communities. KYRC is illustrative of the recent resurgence of sporting activism in the 2010s and early 2020s, in conjunction with the broader Black Lives Matter (BLM) social movement. Not only is Kaepernick a symbolic figure of both athletic protest and Black resistance more generally in this era, but KYRC is representative of how contemporary sporting activism has evolved in more radical, coordinated, and grassroots directions. Because these emerging sporting initiatives more closely resemble the character of social movements organizations than traditional sport-for-development or sporting philanthropy initiatives, I propose conceptualizing these grassroots organizations as Sporting Social Movement Organizations (SMOs). Borrowing from social movement frameworks, I examine KYRC as a Sporting SMO, defined as an organization that utilizes its connection to sport or athletes to pursue social, political, or cultural change in a coordinated, strategic, and sustained manner. While scholars within Physical Cultural Studies and related fields have outlined the historical significance of and public reactions to this resurgence in sporting activism, there remains a considerable lack of theoretically and empirically rigorous research into Sporting SMOs, let alone with data collected in collaboration with organizations that can speak to their inner workings and on-the-ground mechanics. This project fills these gaps. The underlying research question is: in what ways, and within what broader sociopolitical contexts, does Know Your Rights Camp conduct grassroots sporting activism? First, based on in-depth interviews with KYRC associates, content analysis of KYRC’s social media, and textual analyses of KYRC’s public-facing pedagogical documents, I conduct a micro- and meso-level sociological analysis of KYRC’s mechanics, logics, strategies, messages, tensions, and challenges of KYRC’s model of grassroots activism. Second, based in the methods of radical contextualism and articulation, I conduct a macro-level cultural studies analysis of the social, political, economic, historical, technological, and ideological contexts within which KYRC is situated. Overall, this dissertation contains a precise sociological analysis of what KYRC is and does, as well as a broader cultural studies analysis of what KYRC tells us about sport, race, and politics in contemporary America. To summarize the key findings, I suggest that KYRC is simultaneously a Black Radical political project, a form of celebrity sporting activism, a team-based Sporting SMO, a grassroots pedagogical project, and an anti-essentialist progressive conjunctural response to racial capitalism/neoliberalism. KYRC’s blueprint of grassroots activism can be characterized as the symbolic mobilization of high-profile celebrity association and the material mobilization of philanthropy/donor contributions for the purposes of youth empowerment, collective community uplift, and critical public pedagogy. KYRC is propelled by the Kaepernick Brand – referring to Kaepernick’s stature as a global commercial symbol of bold and authentic political resistance – which uniquely affords the organization material and symbolic resources that the KYRC team strategically channels into navigating the non-profit sector and serving its communities with critical education and rapid community response. Based on these findings, I argue that KYRC reveals the political and transgressive potentials inherent to the immense economic and cultural expansion of sport, in ways that urge us to reconsider our assumptions about sport’s emancipatory potential and heighten our expectations of Black (celebrity) athletes. More broadly, KYRC demonstrates how the Left can intervene through the terrain of popular culture to resist neoliberalism and the Right’s reactionary authoritarian populism, and instead articulate a vision for America based in abolition, solidarity, and liberation from all forms of oppression.Item Effects of exercise and inflammation on circulating microparticles(2024) Heilman, James; Prior, Steven J.; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Circulating microparticles (MPs), a subset of extracellular vesicles, have been implicated as novel biomarkers connected to vascular dysfunction. As such, they may contribute to atherosclerosis, hypertension, and other conditions leading to cardiovascular disease. MPs are involved in cell-to-cell communication in response to apoptosis and activation of the immune and inflammatory response, transferring their contents to nearby cells and effectively spreading each condition. The objective of this dissertation was to explore how circulating MP number and function are affected by stimuli such as diet and exercise. Our first study examined how post-prandial inflammation caused by a high-fat meal affects circulating MP number and function in young, healthy adults. We determined that a high fitness level may have a protective effect against the inflammatory load posed by a high-fat meal. The second study determined the effects of acute high-intensity interval aerobic exercise versus acute moderate intensity continuous aerobic exercise on circulating MP number and function in overweight versus lean recreationally active adults. We found that MPs and arterial stiffness in overweight individuals are differentially impacted by the type of acute exercise. Our findings suggest that overweight individuals undergo a greater inflammatory response following high-intensity exercise compared to lean. The third study investigated the effects of a 6-month aerobic exercise training program on circulating MP counts and function in previously sedentary older adults. While we found no effect of the exercise training program on MPs, we provide insight into how improvements in cardiovascular fitness as well as higher exercise intensities may be needed to see changes in MP number and function following aerobic exercise training in older adults. For the first time, we have shown that both dietary inflammation and acute exercise can significantly impact MP function. Furthermore, we have shown that fitness status and body composition play important roles in determining MP number and function after each stimulus. Our findings provide novel insight into how MPs contribute to various types of inflammation as well as how they may be used as biomarkers to measure the progression of cardiovascular disease.Item A CASE STUDY OF RED BULL’S USE OF SPORTING EVENTS IN THE NEOLIBERAL URBAN ENVIORNMENT(2024) Weber, Emilio; Andrews, David L.; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This project critically examines the ways in which city space and place are mobilized for capital interests through an examination of the global sports and energy drinks brand, Red Bull, and specifically its urban-based event strategies. The events such as the ones Red Bull hosts, alongside other spectacular urban projects have been prominent endeavors in which the lived experience of space has been reformulated by those who wield power and influence in the city. Informed by the contextual forces and logics of neoliberal urbanism, Red Bull strategically deploys the physical and symbolic reformulation of cities as an important aspect of its brand marketing strategy. The company, alongside local entities, impact the physical environment of the urban areas they occupy for the events. In addition, representations of places are presented and altered. These alterations of urban space and place have included an increased focus on spectacular consumption sites and experiences, in addition to the policing and surveillance of such spaces. Furthermore, this thesis offers analytical insight into the ways Red Bull’s urban strategizing is both and product and producer of the normalized neoliberal fabric that has come to envelope the contemporary US city: ultimately reproducing urban spaces which promote private profit and continue or exacerbate the inequalities felt in cities. Drawing from a range of interdisciplinary scholarship, I examine the relationship between, and impact of, sporting events hosted within the context of neoliberal cities. Deploying theoretical frameworks based in urban studies, neoliberalism, and critical geography informs the literature review and my research. This literature includes, but is not restricted to, physical cultural studies, urban studies, the sociology of sport, and event literature. Additionally, I utilize a case study method to examine the nature of the events within the urban and sport context they take place in. Completing field research and participant observation at three Red Bull sporting events, hosted in three distinct locales in June 2023, August 2023, and February 2024, I focus on the composition, meaning, affect, and experience of urban space, as created by the event itself, alongside marketing and promotional strategies of the company and cities in relation to these events. The research findings are divided into two empirical chapters, focused on the material and symbolic impacts upon urban space and place, respectively. I posit these findings as a normalized occupation of urban space, following the logics of neoliberalism and the event/content production of Red Bull. In conforming to neoliberal capitalist ideas focused on commercialized spectacle, these events simultaneously work to normalize this corporate use of urban space.