The authors conducted a systematic review of children’s and adolescent’s physical activity by schoolyard location. PubMed and Web of Science were searched and articles were selected that included 3- to 17-year-olds and specifically examined and reported physical activity by schoolyard location. The primary outcomes of interest were the percentage of total time or observation intervals spent in each location and percentage of time or observation intervals in each location being sedentary or participating in moderate to vigorous physical activity. Included studies (N = 24) focused on preschoolers (n = 6), children (n = 11), adolescents (n = 2), or children and adolescents (n = 5) and primarily used direct observation (n = 17). Fields, fixed equipment, and blacktop were all important locations for physical activity participation, but there were differences by age group and sex. More research is needed that uses consistent methodology and accounts for other factors such as time of year, provided equipment, and differences in schoolyard designs.
Kimberly A. Clevenger, Michael J. Wierenga, Cheryl A. Howe and Karin A. Pfeiffer
Geoffrey T. Burns, Kenneth M. Kozloff and Ronald F. Zernicke
Movement is essential to the human experience, and efficient biomechanics facilitate effective action across the breadth of tasks one encounters in life. The concept of movement efficiency has been investigated and explored through a variety of means including biomechanical modeling, simulation, and experimental manipulation. Observations of elite performers for a given movement task serve as an additional line of insight into efficiency, as their movements have been driven toward optimization via competitive pressure. The authors first discuss the concept of efficiency in biomechanics from a qualitative perspective and the broad tools with which we explore it. They then highlight biomechanical investigations of elite performers and their contributions to our understanding of efficiency. Examples from various classes of movements illustrate unique insights of the elite performers in informing our understanding of movement efficiency.
Kevin M. Guskiewicz and Samuel R. Walton
It was not too long ago that many people referred to concussion as a “hidden injury” and a “complex injury for which we still had much to learn.” We still have a lot to learn about these injuries, but because of the advancement of concussion research we are better informed today than we were just a decade ago. Much of this work began in the early to mid-1990s with studies aimed at equipping clinicians with better concussion-assessment tools. We needed to remove the guesswork, so more systematic and objective concussion-assessment batteries (sideline and clinic) that included symptom checklists, cognitive tests, and balance assessments were developed and validated. As a result, it became easier to detect and/or rule out concussions and to track recovery for several days postinjury. From 2009 through 2014, all 50 states and the District of Columbia passed concussion legislation requiring concussion education for high school and youth athletes, among other things. This was a critical period in which more emphasis was placed on concussion prevention, ultimately leading to increased reporting of these injuries and a reduction in the number of unreported and undiagnosed concussions. More recently, the corpus of science has evolved to identify potential blood and neuroimaging biomarkers to complement the traditional-clinical assessment tools, and newer studies are focused on treatment after concussion—challenging the notions that “rest is best” and that the effects of concussion are permanent and immutable. The research is ongoing, and several large multisite studies will yield important findings to help guide clinical decision making in the next few years.
Margaret C. Morrissey, Michael R. Szymanski, Andrew J. Grundstein and Douglas J. Casa
Intense exercise in extreme heat can increase the risk of developing exertional heat stroke (EHS). EHS is 100% survivable with appropriate care, and it is imperative that health care professionals recognize predisposing factors that may increase susceptibility to EHS. Understanding risk factors for EHS will enable clinicians to create effective prevention strategies to improve exercise heat tolerance and mitigate EHS risk. This review addresses new perspectives on risk factors for EHS that focus on hydration, heat acclimatization, medical conditions, climate change and policies, medications, and strength and conditioning sessions.
Bradley D. Hatfield, Calvin M. Lu and Jo B. Zimmerman
Mark S. Dyreson
Since the origins of Homo sapiens 300,000 years ago, the quest to optimize human performance has shaped historical development. A macrohistorical perspective reveals that for 290,000 years the necessities of survival pushed hunter-forager cultures toward mass improvement of endurance capabilities and weapons skills. The agricultural revolution that began about 10,000 years ago changed those dynamics, focusing on enhancement for elite warriors while simultaneously diminishing the necessity of mass optimization. The multiple revolutions of modernity that began 500 years ago reanimated mass optimization while paradoxically removing physical enhancement from the realm of necessity through the increasing power of human-made motors rather than human locomotion. Microhistorical perspectives reveal that beyond the general patterns that shaped human cultures across time and place, the historical particularities vastly complicated optimization strategies. Employing macro- and microhistorical perspectives can enhance scientific understandings of optimal performance.
Sandra J. Shultz and Randy J. Schmitz
Despite considerable advances in anterior cruciate ligament (ACL) injury-risk identification and prevention over the past 20 years, the annual incidence of ACL injury has continued to rise, and females remain at greater risk of both primary and secondary ACL injury. Important questions remain regarding ancillary risk factors we should target, the most effective training and rehabilitation approaches to ensure retention and transfer of learned skills from the rehabilitation setting to real-world sporting environment, and the development of more evidence-based criteria for return to sport that consider the whole athlete. As we look to the future, the optimization of primary and secondary ACL-injury prevention represents a complex, multidisciplinary problem with many unique and exciting opportunities to engage the various subdisciplines of kinesiology to address these emerging questions.
This paper identifies several factors that lie within and external to the teaching act that have an impact on the quality of instruction that students can potentially receive, which in turn has implications for the extent to which students can engage in appropriate practice. These factors all exist on a continuum from limiting to enhancing, and we could hypothesize that they regulate the possibilities for practice that are afforded to students and that this practice time is considered in the development of competent movers in physical education. These factors are contextual, such as time, class size, and teaching resources; curricular, relating to the content and pedagogy of physical education; and instructional, such as teacher effectiveness and content knowledge.