Cutaneous reflexes have been described primarily according to their actions in the flexion/extension plane. It is shown here, by measuring electromyography and isometric force in decerebrate cats, that ankle muscles are activated in relation to their actions in the abduction/adduction plane during sural nerve (SNR) and crossed-extension (XER) reflexes. Ankle adductors (tibialis posterior, extensor digitorum longus, and flexors digitorum and hallucis longus) were active in XER, but not in SNR. Muscles producing ankle abduction (medial and lateral gastrocnemii and peroneus longus and brevis) were often activated in both reflexes, and medial gastrocnemius and peroneus longus were consistently more strongly activated in SNR than in XER. This differential pattern of muscle activation results in greater abduction torque at the ankle in SNR than in XER. These data demonstrate reflex organization in relation to the multidirectional torque generated by individual muscles.
Sondra G. Siegel, T. Richard Nichols and Timothy C. Cope
John R. Biggan, Forest Melton, Michael A. Horvat, Mark Ricard, David Keller and Christopher T. Ray
The understanding of prefrail and nonfrail older adults’ postural control with and without increased environmental and cognitive stress is imperative to the development of targeted interventions to decrease fall risk within these populations. Thirty-eight individuals participated in this study. Postural control testing included the Sensory Organization Test (SOT) on a NeuroCom EquiTest. Cognitive and environmental load testing was performed during Condition 6 of the SOT. Though there were no group differences on composite equilibrium score (p = .06), the cognitive task (Stroop task) impaired equilibrium scores more than the auditory or visual distracter tasks (p < .05 and p < .01) for both groups. These results suggest that both prefrail and nonfrail older adults’ postural control is reduced in demanding environments. Given these findings, the need for multimodal exercise interventions to target both physical and cognitive factors is apparent.
Alan B. Stevens, Shannon B. Thiel, Jennifer L. Thorud, Matthew Lee Smith, Doris Howell, Jessica Cargill, Suzanne M. Swierc and Marcia G. Ory
Many initiatives have been developed to facilitate older adults’ engagement in physical activity (PA) and document its benefits. One example is Texercise, a 12-week program with a focus on increasing participants’ self-efficacy. The goal of this paper is to augment the knowledgebase of PA program implementation and dissemination by elucidating the experience of Texercise implementation as perceived by multiple stakeholders. We conducted 28 semistructured stakeholder interviews and categorized the responses into four preset themes: (1) program delivery and advocacy; (2) value/merit of the program; (3) successes/challenges of offering and sustaining the program; and (4) recommendations for enhancing implementation and delivery. We identified emergent subthemes through further analysis. Many perceptions that are broadly applicable to community organizations emerged. Our findings highlight the importance of stakeholder support when embedding PA programs in communities. Furthermore, the findings are crucial to understanding underlying processes that support widespread program dissemination and sustainability.
Heidi L. Keller, Stephen E. Tolly and Patty S. Freedson
The sport of wrestling often encourages participants to engage in extreme weight loss practices in order to compete in a weight class one to three weight categories below normal weight. This review discusses the prevalence of the problem, methods wrestlers use to accomplish weight loss, and the health and performance consequences of rapid weight loss, with particular emphasis on weight cycling and minimal safe wrestling weight assessment. Some useful and practical recommendations for minimizing extreme weight loss practices are presented. Several state wrestling associations have adjusted their rules and regulations based on recommendations by organizations such as the American College of Sports Medicine to reduce the prevalence of the problem. Nevertheless, extreme weight loss continues to be a concern among health professionals, particularly with regard to health and performance.
Melvin H. Williams
As nutritional technology advanced, scientists have been able to synthesize and manufacture all known nutrients, and many of their metabolic by-products, essential to human physiology. Many of these substances are theorized to possess ergogenic potential when take in quantities or forms normally not found in typical foods or diets. Research, although limited in most cases, supports the ergogenicity of some nutrients (e.g., creatine) when consumed in substantial amounts, suggesting such nutrients may function as drugs or nutraceuticals. The International Olympic Committee (IOC) doping legislation stipulates that any physiologic substance taken in abnormal quantity with the intention of artificially and unfairly increasing performance should be construed as doping, violating the ethics of sport performance. Given this stipulation, the IOC and other athletic-governing organizations should consider the legality and ethics underlying the use of ergogenic nutraceuticals in sport.
David Cardenas, Karla A. Henderson and Beth E. Wilson
The purpose of the article was to examine the physical activity perceptions and behaviors of older adults who were active participants in a statewide senior games (i.e., North Carolina Senior Games; NCSG) program with its focus on year-round involvement through activities in local communities. A random sample of 440 older adults (55 years and older) completed a questionnaire in 2006 about their participation in community-based senior games. A uniqueness of this study is its focus on active older adults, which provides insight into how to maintain physical involvement. Older adults who were most active perceived the most benefits from senior games but did not necessarily have the fewest constraints. This study of NCSG as an organization designed to promote healthy living in communities offered an example of how a social-ecological framework aimed at health promotion can be applied.
Maureen Lucas and Cynthia J. Heiss
Protein recommendations by some professional organizations for young adults engaged in resistance training (RT) are higher than the recommended dietary allowance (RDA), but recommendations for resistance-training older adults (>50 years old) are not well characterized. Some argue that the current RDA is adequate, but others indicate increased protein needs. Although concerns have been raised about the consequences of high protein intake, protein intake above the RDA in older adults is associated with increased bone-mineral density when calcium intake is adequate and does not appear to compromise renal health in older individuals with normal renal function. Individual protein needs for older adults in RT are likely highly variable according to health and training regimen, but an intake of 1.0–1.3 g · kg−1 · day−1 should adequately and safely meet the needs of older adults engaged in RT, provided that their energy needs are met.
Kathleen Benjamin, Nancy Edwards and Wenda Caswell
In 2006, the authors conducted a multisite qualitative study in Ottawa, Ontario, Canada to examine organizational and environmental factors that influence physical activity for long-term-care (LTC) residents. The article describes the results of interviews with 9 administrators from nonprofit and for-profit LTC facilities. A content analysis revealed that despite having positive views about the value of physical activity, the administrators encountered challenges related to funding, human resources, and the built (physical) environment. The intersection of staffing issues and challenges in the built environment created less than optimal conditions for physical activity programs. Findings suggest that until there are adequate human and financial resources, it will be difficult to implement evidence-informed physical activity programs for residents in LTC settings in Ontario. A review of provincial LTC standards for physical activity program requirements and the built environment is warranted.
Claudia Meyer, Susan Williams, Frances Batchelor and Keith Hill
The aim was to identify barriers and opportunities facing community health physiotherapists in delivering a home-based balance exercise program to address mild balance dysfunction and, secondly, to understand the perspectives of older people in adopting this program.
Focus groups, written surveys, and data recording sheets were used with nine older people and five physiotherapists. Focus groups were audio taped, transcribed, and coded independently by two researchers.
Thematic content analysis was undertaken. Emerging themes were: engaging in preventive health (various benefits, enhancing independence); adoption of strategies (acceptable design and implementation feasibility); exercising in context (convenience, practicality, and safety); and broader implementation issues (program design, proactive health messages, and a solid evidence base).
The views of older people and physiotherapists were sought to understand the adoption of a previously successful home-based program for mild balance dysfunction. Understanding the unique context and circumstances for individuals and organizations will enhance adoption.
Kathleen Benjamin, Nancy Edwards, Jenny Ploeg and Frances Legault
Despite the benefits of physical activity, residents living in long-term care (LTC) are relatively sedentary. Designing successful physical activity and restorative care programs requires a good understanding of implementation barriers. A database search (2002–2013) yielded seven studies (nine articles) that met our inclusion criteria. We also reviewed 31 randomized controlled trials (RCTs) to determine if the authors explicitly discussed the barriers encountered while implementing their interventions. Eleven RCTs (13 articles) included a discussion of the barriers. Hence, a total of 18 studies (22 articles) were included in this review. Barriers occurred at resident (e.g., health status), environmental (e.g., lack of space for physical activity), and organizational (e.g., staffing and funding constraints) levels. These barriers intersect to adversely affect the physical activity of older people living in LTC. Future studies targeting physical activity interventions for residents living in LTC are needed to address these multiple levels of influence.