An optimal level of variability enables us to interact adaptively and safely to a continuously changing environment, where often our movements must be adjusted in a matter of milliseconds. A large body of research exists that demonstrates natural variability in healthy gait (along with variability in other, healthy biological signals such as heart rate) and a loss of this variability in aging and injury, as well as in a variety of neurodegenerative and physiological disorders. We submit that this field of research is now in pressing need of an innovative “next step” that goes beyond the many descriptive studies that characterize levels of variability in various patient populations. We need to devise novel therapies that will harness the existing knowledge on biological variability and create new possibilities for those in the grip of disease. We also propose that the nature of the specific physiological limitation present in the neuromuscular apparatus may be less important in the physiological complexity framework than the control mechanisms adopted by the older individual in the coordination of the available degrees of freedom. The theoretical underpinnings of this framework suggest that interventions designed to restore healthy system dynamics may optimize functional improvements in older adults. We submit that interventions based on the restoration of optimal variability and movement complexity could potentially be applied across a range of diseases or dysfunctions as it addresses the adaptability and coordination of available degrees of freedom, regardless of the internal constraints of the individual.
Nicholas Stergiou, Jenny A. Kent and Denise McGrath
Jennifer J. Heisz and Ana Kovacevic
Age-related changes in the brain can compromise cognitive function. However, in some cases, the brain is able to functionally reorganize to compensate for some of this loss. The present paper reviews the benefits of exercise on executive functions in older adults and discusses a potential mechanism through which exercise may change the way the brain processes information for better cognitive outcomes. Specifically, older adults who are more physically active demonstrate a shift toward local neural processing that is associated with better executive functions. We discuss the use of neural complexity as a sensitive measure of the neural network plasticity that is enhanced through exercise. We conclude by highlighting the future work needed to improve exercise prescriptions that help older adults maintain their cognitive and physical functions for longer into their lifespan.
Karl M. Newell and Steven Morrison
This paper presents a framework for an evolving dynamical landscape of movement forms and their stability over the lifespan. It is proposed that the complexity and dimensionality of movement forms can expand and contract on a number of growth/decay time scales of change including those of adaptation, development, and learning. The expansion and contraction is reflected in: (1) the range of potential movement forms of the individual in developmental time; and (2) the dimensionality and complexity of any single movement form at a moment of observation given the confluence of individual, environmental, and task constraints. It is postulated that practice, exercise, and fatigue also coalesce to change the time scales of complexity and dimension of movement forms.
Edmund O. Acevedo and Aaron L. Slusher
The relationship between stress and disease, in particular cardiovascular disease, has long been recognized, whereas the study of the physiological mechanisms that explain this link has only more recently received attention. The acute response to stress is generally thought to be a critically important adaptation designed to activate the system in preparation to cope with the stressor. However, prolonged stimulation of the system (acute and chronic) can lead to deleterious adaptations including the release of inflammatory cytokines (small proteins important in cell signaling) that play a critical role in the development of atherosclerosis. Scientists have therefore used a breadth of protocols and methods to identify the complexity of our fight-or-flight response and demonstrate the synergy between perception, the stress response, physical activity, and health. In addition, the critical assessment of cellular health, the gut microbiome, and genetic polymorphisms have further advanced our understanding of additional therapeutic targets against CVD.
R. Scott Kretchmar
The 2012 Academy meeting focused on research related to increasing levels of physical activity and promoting persistence. Speakers agreed that answers would be hard to come by but that progress was possible. Emphases for potential solutions ranged from the cellular to the cultural, from neural mechanisms to symbolic processes, from particle physics to philosophy. Strategies for intervention were diverse and refected a series of dynamical tensions—behavioral and nonbehavioral, cognitive and noncognitive, traditional and nontra-ditional, environmental and motivational, and finally medical in contrast to educational. It is likely, given the complexities inherent in increasing movement behaviors and assuring persistence, that various blends of solutions emerging from multiple points on the disciplinary landscape and honoring truths that run across these strategic tensions will be needed.
Kevin M. Guskiewicz
“Concussion” is all over the news, and—yes—it has implications for combating chronic diseases such as obesity and diabetes. Many parents are pushing their children away from collision sports such as football, hockey, and lacrosse because they fear the risk of chronic neurodegenerative problems later in life. However, there is good logic in emphasizing the importance of physical activities such as collision type sports, during the developmental years. Physical educators, researchers, policy makers, and coaches must work together to encourage safe play and rules changes that can keep youth and adolescents active in sports that build character, discipline, and teach teamwork. Understanding the complexity of the highly adaptable adolescent brain both prior to and following sport-related concussion is critically important in accomplishing this goal.
Hendrik Reimann, Tyler Fettrow and John J. Jeka
The neural control of balance during locomotion is currently not well understood, even in the light of considerable advances in research on balance during standing. In this paper, we lay out the control problem for this task and present a list of different strategies available to the central nervous system to solve this problem. We discuss the biomechanics of the walking body, using a simplified model that iteratively gains degrees of freedom and complexity. Each addition allows for different control strategies, which we introduce in turn: foot placement shift, ankle strategy, hip strategy, and push-off modulation. The dynamics of the biomechanical system are discussed using the phase space representation, which allows illustrating the mechanical effect of the different control mechanisms. This also enables us to demonstrate the effects of common general stability strategies, such as increasing step width and cadence.
K. Andrew R. Richards, Colin G. Pennington and Oleg A. Sinelnikov
Occupational socialization theory (OST) has framed research on physical education (PE) teacher recruitment, professional preparation, and ongoing socialization in schools for nearly 40 yr. Using scoping-review methods, the authors sought to understand the current scope of published research on PE-teacher socialization using OST by descriptively and thematically reviewing 111 identified studies published in English-language journals between 1979 and 2015. Results indicate a predominance of qualitative, cross-sectional research related to PE-teacher socialization, most of which was conducted by a relatively small group of scholars. Themes derived from the analysis of study findings communicate the complexity of teacher socialization experiences and are used to develop recommendations for future research and practice that work toward helping improve teachers’ lived experiences while creating better contexts in which students can learn. The paper concludes with a discussion of extending OST research to understand the recruitment, professional education, and socialization of kinesiology faculty members and professionals across subdisciplines.
The experiences of women in physical education history from the nineteenth century forward offer us valuable insights toward a better understanding of the discipline since its inception. The deeply gendered histories of women in the profession are contingent upon the ways in which they intersect with other identities, including class, race, and sexuality. Dominant gender ideologies were reinforced and resisted in women’s physical education, making it a significant location to understand how bodies were constructed and reconstructed within ever-changing societal definitions of gender and athletic femininity. The contradictions and complexities that emerge as a result of the many gender tensions in play over the course of this history produce a rich site to more completely understand the discipline’s past and future.
In this paper I view the history of kinesiology in America through the lens of a shifting academic landscape where physical culture and building acted upon each other to reflect emergent views concerning the nature of training in physical education and scientific developments around human movement. It is also an organizational history that has been largely lived in the gymnasium and the laboratory from its inception in the late nineteenth century to its current arrangements in the academy. Historians have referred to this in appropriately embodied terms as the head and the heart of physical education, and of course the impact of gender, class, and race was ever present. I conclude that the profession/discipline conundrum in kinesiology that has ebbed and flowed in the shifting spaces and carefully organized places of the academy has not gone away in the twenty-first century and that the complexities of today’s training require more fertile and flexible collaborative approaches in research, teaching, and professional training.