Despite extensive research, we still do not fully understand the biological mechanisms that underlie a female's increased susceptibility for suffering a noncontact ACL injury. While sex differences in neuromuscular control are often implicated, prevention efforts addressing these differences have not resulted in a profound or sustainable reduction in injury rates. This paper will explore two likely scenarios that explain this greater susceptibility in females: (1) females have a structurally weaker ligament that is more prone or susceptible to failure at a given load (scenario #1), or (2) females develop less knee protection and experiences higher relative loads on the ACL (scenario #2). While we have learned much over the last two decades about ACL injury risk in females, much remains unknown. Continued research is of paramount importance if we are to effectively identify those females who are at greatest risk for injury and effectively reduce their susceptibility through appropriate interventions.
ACL Injury Risk in the Physically Active: Why are Females More Susceptible?
Sandra J. Shultz
Childhood Physical Activity May or May Not Provide Sustained Effects to Protect Adults From Osteoporosis
Kathleen F. Janz and Shelby L. Francis
Although there is strong and consistent evidence that childhood and adolescent physical activity is osteogenic, the evidence concerning its sustained effects to adult bone health is not conclusive. Therefore the value of interventions, in addition to beneficial bone adaptation, could be exposure to activities children enjoy and therefore continue. As such, interventions should provide skills, pleasure, and supportive environments to ensure continued bone-strengthening physical activity with age. Until the dose-response as well as timing of physical activity to bone health is more fully understood, it is sensible to assume that physical activity is needed throughout the lifespan to improve and maintain skeletal health. Current federal guidelines for health-related physical activity, which explicitly recommend bone-strengthening physical activities for youth, should also apply to adults.
Determinants of Elite Disability Sport Performance
Jeffrey J. Martin
In the last 10-20 years sport psychologists have started to emphasize the value of mental strengths such as self-confidence for disability sport athletes (Martin, 2012). The pinnacle of disability sport competition, the Paralympics, is becoming increasingly competitive, suggesting a strong need for athletes to possess effective mental skills. Like the Olympics there is intense pressure to win at the Paralympics. In the current review article I discuss the body of knowledge in sport psychology that focuses on potential direct and indirect determinants of performance in elite disability sport. The review is organized around a personnel developmental model used by Martin (1999, 2005, 2012). This model is a humanistic model and revolves around foundation qualities, psychological methods and skills, and facilitative and debilitative factors. The premise of the model is also similar to McCann's sentiment that “at the Olympics [Paralympics], everything is a performance issue” (2008, p. 267).
Effects of Progressive Resistance Exercise Training on the Motor and Nonmotor Features of Parkinson's Disease: A Review
Guillaume Lamotte, Elizabeth Skender, Miriam R. Rafferty, Fabian J. David, Steve Sadowsky, and Daniel M. Corcos
This paper reviews the therapeutically beneficial effects of progressive resistance exercise training (PRET) on motor and nonmotor symptoms in Parkinson's disease (PD).
First, we perform a systematic review of the literature on the effects of PRET on motor signs of PD, functional outcomes, quality of life, and patient perceived improvement, strength, and cognition in PD. Second, we perform a meta-analysis on the motor section of the UPDRS. Finally, we discuss the results of our review and we identify current knowledge gaps regarding PRET in PD.
This systematic review synthesizes evidence that PRET can improve strength and motor signs of Parkinsonism in PD and may also be beneficial for physical function in individuals with PD. Further research is needed to explore the effects of PRET on nonmotor symptoms such as depression, cognitive impairment, autonomic nervous system dysfunction, and quality of life in individuals with PD.
Environments Change Child Behavior, But Who Changes Environments?
John B. Bartholomew
Numerous interventions have been designed to modify children's physical activity and eating behaviors. While early research centered on the individual as the target of intervention, more recent work targets change in the environment. These studies have consistently supported the importance of environmental contributors to both physical activity and eating behavior, but little research has considered those who are responsible for implementing environmental change. For example, if we expect school environments to support activity and healthy eating, we must consider the motivation of school administrators to affect change. This review will present examples of an ecological approach to behavior change along with recent data to support this approach.
The Nexus of Rehabilitation and Exercise: Where and Why the Two Shall Meet
James H. Rimmer
People with newly acquired and existing disability have one of the highest rates of physical inactivity compared with any other subgroup in the United States. For more than 50 million Americans with disabilities, lack of regular exercise increases their risk for developing the health problems associated with a sedentary lifestyle. Professionals in rehabilitation and exercise science must join forces in promoting higher levels of physical activity among people with newly acquired or existing disability after they are discharged from rehabilitation. Establishing a strong and cohesive relationship between rehabilitation providers and exercise professionals at the ‘infection point’ when rehabilitation ends and sustainable exercise must begin will capture individual awareness and knowledge of how and why extending the recovery process into community-based exercise facilities has substantial potential for improving their health and quality of life.
Optimizing the Exercise Drug for Metabolic Rehabilitation
The concept that participation in exercise/physical activity reduces the risk for a host of chronic diseases is undisputed. Along with adaptations to habitual activity, each bout of exercise induces beneficial changes that last for a finite period of time, requiring subsequent exercise bouts to sustain the benefits. In this respect, exercise/physical activity is similar to other “medications” and the idea of “Exercise as Medicine” is becoming embedded in the popular lexicon. Like other medications, exercise has an optimal dose and frequency of application specific to each health outcome, as well as interactions with food and other medications. Using the prevention of type-2 diabetes as an exemplar, the application of exercise/physical activity as a medication for metabolic “rehabilitation” is considered in these terms. Some recommendations that are specific to diabetes prevention emerge, showing the process by which exercise can be prescribed to achieve health goals tailored to individual disease prevention outcomes.
Physical Activity Alone May Enhance Health But It May Not Reduce Disability in Chronic Stroke Survivors
In this paper, I argue that physical activity in the form of exercise provides wonderful health benefits for individuals with chronic stroke but fails to also reduce the wider effects of disability for these individuals. The argument proceeds first with a definition of terms, including the classification framework of health and disability according to the World Health Organization. Next follows a section on stroke, its prevalence, and major motor symptoms, including health status. The subsequent two sections include evidence for the health benefits of exercise and lack of evidence for the reduction of disability. The penultimate section expands upon the direction of research that should move us toward reducing disability. The final section concludes on how kinesiology fits into a model for improving both health and reducing disability for chronic stroke survivors.
Physical Activity, Exercise, and the Immune System: Three Lines of Research That Have Driven the Field
Jeffrey A. Woods and Brandt D. Pence
Exercise immunology is a relatively new discipline in the exercise sciences that seeks to understand how exercise affects the immune system and susceptibility to infectious and chronic diseases. This brief review will focus on three major observations that have driven the field to date including: (1) acute exercise-induced leukocytosis, (2) the observation that intense, prolonged exercise results in upper respiratory tract symptoms, and (3) the paradoxical effect of acute and chronic exercise on inflammation. This framework will be used to examine the mechanisms and implications behind these seminal observations. Data generally support the conclusion that moderate intensity exercise enhances immune function, whereas prolonged, intense exercise diminishes immune function.