Lower limb joint kinetics in the starting blocks and first stance in athletic sprinting

The aim of this study was to examine lower limb joint kinetics during the block and first stance phases in athletic sprinting. Ten male sprinters (100 m PB, 10.50 ± 0.27 s) performed maximal sprint starts from blocks. External force (1000 Hz) and three-dimensional kinematics (250 Hz) were recorded in both the block (utilising instrumented starting blocks) and subsequent first stance phases. Ankle, knee and hip resultant joint moment, power and work were calculated at the rear and front leg during the block phase and during first stance using inverse dynamics. Significantly (P < 0.05) greater peak moment, power and work were evident at the knee joint in the front block and during stance compared with the rear block. Ankle joint kinetic data significantly increased during stance compared with the front and rear block. The hip joint dominated leg extensor energy generation in the block phase (rear leg, 61 ± 10%; front leg, 64 ± 8%) but significantly reduced during stance (32 ± 9%), where the ankle contributed most (42 ± 6%). The current study provides novel insight into sprint start biomechanics and the contribution of the lower limb joints towards leg extensor energy generation.     

Validity of block start performance without arm forces or by kinematics-only methods

The purpose of this study was to validate the calculation of reaction time (RT) and normalised power in block starts without considering arm ground reaction forces (GRFs) or using two kinematics-only methods. The RT and normalised power in the action phase were calculated using four different methods: using GRFs of arms and legs by force plates (whole F-based method), which can be regarded as the most valid method, using GRFs of legs captured by force plates (legs F-based method), using position of the centre of mass of the entire body captured by high-speed cameras (whole P-based method), and using only a partial subset of segment position (partial P-based method). Bland–Altman plots demonstrated that the RT of the legs F-based method was not similar to that of the whole F-based method: the mean difference was 7.4 ms and the 95% limits of agreement was?45.1 to 59.8 ms, and it was the least valid method for the calculation among the four methods. In contrast, the normalised power was more valid in the legs F-based method, followed by whole and partial P-based methods. This information will help researchers and practitioners to decide upon their analysis methods when analysing block start performance.     

The relationship between physical activity,fitness, physical complaints and BMI in German adults – results of a longitudinal study

Objectives: This study’s aims were to describe the development of physical activity, physical fitness (PF), subjective (physical complaints (PC)) and objective (Body mass index (BMI)) health measures and to examine the relationship between the development trajectories. In addition, the study also aimed to assess the influence of sociodemographic determinants (age, sex, socioeconomic status (SES)) in German adults over a period of 18 years. Methods: The longitudinal study population comprises of 721 men and women, aged 33–76 years over the study period. There was self-report of physical activity and PC and testing of physical fitness and BMI in each study year (1992, 1997, 2002 and 2010). Latent growth curve models were used to analyse the development. Results: Physical activity slightly increased while fitness, PC and BMI worsened over the course of 18 years. Sex, age and SES play important roles concerning physical activity, fitness and health. Several integrative associations could be detected between physical activity, fitness, PC and BMI as well as their trajectories. In particular, high initial levels of physical activity and fitness protect from high PC and BMI.The slope of physical activity was not significantly associated with slopes of fitness, PC and BMI. However, increase of fitness resulted in decrease of PC. Conclusions: A general positive development regarding the amount of physical activity could be detected. However, if it is only an unsystematic increase of physical activity, this is not in itself enough to achieve health benefits. The strengthening of fitness should be focused when increasing physical activity, since only then a health benefit is possible.     

Ganma theory and third-sector sport-development programmes for Aboriginal and Torres Strait Islander youth: Implications for sports management

Sport-development programmes provide opportunities for Aboriginal and Torres Strait Islander youth to excel and overcome social inequities. In Australia, all levels of government have identified sport-development programmes in their policy responses as a method to redress inequity amongst this population. Yet, a recent report has shown that national sport organisations have been more reactive in establishing anti-discrimination policy and less proactive in cultivating culturally inclusive programmes and meaningful sporting experiences (Human Rights and Equal Opportunity Commission, 2007). At the same time, neo-liberal approaches to policy in Australia have seen the emphasis on grassroots community sport-development shift to third-sector organisations. However, little research has examined how the third-sector organisations operate with Aboriginal and Torres Strait Islander communities and how culturally inclusive the programmes they deliver are for the communities in which they operate. Three case studies with the objectives of analysing organisational approaches to: structure and governance; sport-development philosophies; and cultural inclusiveness of the programmes, are presented here. The case studies were informed by the cultural lens of Ganma, a theory belonging to the Yolngu community of Yirrkala (Marika, Ngurruwutthun, & White, 1992). The case study method included in-depth interviews with programme leaders, reviews of management information systems and programme observation. The findings provided evidence of the importance of culturally inclusive programmes through governance and an informal lived approach to philosophy and culture. The implications for sports management are discussed, including: the benefits of involving Aboriginal and Torres Strait Islander people at the board level; the need for collaboration between local communities and partners; the explicit need to empower local communities to develop the skills to sustain programmes and outcomes; and the maintenance of mutually beneficial interactions.     

Die Körperzusammensetzung von Hobbygamern im Vergleich zu deutschlandweit erhobenen Referenzdaten

About two thirds of adults in Germany are overweight or obese. While an increase in the consumption of high-calorie food is considered the main cause, the influence of various forms of sedentary activities is still controversially discussed. The aim of the present study is to compare the body composition of hobby gamers with reference data collected throughout Germany and to examine the effects of intensive use of computer games (gaming) on body composition. A total of 68 male participants of a computer game event aged 18–46 years (27.9 years; 180.1?cm; 83.5?kg; BMI 25.7) were examined for fat mass, body cell mass, extracellular mass, body water and phase angle using bioelectrical impedance analysis (BIA, Nutriguard MS type, data input). Ten test persons were retested by means of segmental 8?electrode BIA after a 24?h interval during their visit to the event. As a reference sample, data from 278 male adults of the same age (27.9 years, 179.4?cm; 78.8?kg; BMI 24.5) were collected in 168 locations throughout Germany. The hobby gamers reported on average 37.1?h screen media usage per week. Compared to the reference sample, they showed a slightly higher body cell mass index (p?<?0.01, T?=?4.07), but no differences in fat mass index (p?=?0.96, T?=?0.05) and phase angle (p?=?0.90, T?=?0.12). A significant increase in body water (T₀: 48.2?l, T₀₊₂₄?_h: 49.3?l; p?=?0.04, T?=?2.39) and decrease in the phase angle of the lower extremities (T₀:?7.40, T₀₊₂₄?_h: ?6.85; p?<?0.01, T?=?5.40) was observed in the 24?h retest. Compared to the reference data collected throughout Germany, hobby gamers show no differences in health-relevant parameters of body composition. Nevertheless, after intensive gaming, a short-term increase in the amount of extracellular water in the lower extremities was found. Due to these disturbances in the water balance, the consequent execution of movement breaks during gaming is important.     

‘Whys’ and ‘Hows’ of Using Philosophy in Mathematics Education

The article elaborates and exemplifies a potential categorization of the reasons for using philosophy, in particular the philosophy of mathematics, in mathematics education and approaches to doing so—the so-called ‘whys’ and ‘hows’. More precisely, the ‘whys’ are divided into the two categories of ‘philosophy as a tool’ for teaching and learning mathematics, and ‘philosophy as a goal’, referring to a stance of considering it a purpose in itself to teach students certain aspects regarding the philosophy of mathematics. A division of the ‘hows’ into three different categories is offered: illumination approaches; modules approaches; and philosophy-based approaches. A major part of the article is spent on providing illustrative exemplifications of each of these approaches by referring to already implemented uses of philosophy of mathematics in mathematics education as well as by suggesting new ones.     

Spatial Ability Mediates the Gender Difference in Middle School Students' Science Performance

Prior research has demonstrated a male advantage in spatial skills and science achievement. The present research integrated these findings by testing the potential role of spatial skills in gender differences in the science performance of eighth‐grade students (13–15 years old). In 2 (N = 113), the findings showed that mental rotation ability mediated gender differences in physical science and technology/engineering test scores. In 3 (N = 73,245), science performance was examined in a state population of eighth‐grade students. As in 2 , the results revealed larger gender differences on items that showed higher correlations with mental rotation. These findings underscore the importance of considering spatial training interventions aimed at reducing gender differences in the science performance of school‐aged children.     

Exploring data management content in doctoral nursing handbooks

Objective:While data management (DM) is an increasing responsibility of doctorally prepared nurses, little is understood about how DM education and expectations are reflected within student handbooks. The purpose of this study was to assess the inclusion of DM content within doctoral nursing student handbooks.Methods:A list of 346 doctoral programs was obtained from the American Association of Colleges of Nursing (AACN). Program websites were searched to locate program handbooks, which were downloaded for analysis. A textual review of 261 handbooks from 215 institutions was conducted to determine whether DM was mentioned and, if so, where the DM content was located. Statistical analysis was performed to compare the presence of DM guidance by type of institution, Carnegie Classification, and the type of doctoral program handbook.Results:A total of 1,382 codes were identified across data life cycle stages, most commonly in the handbooks’ project requirements section. The most frequent mention of DM was in relation to collecting and analyzing data; the least frequent related to publishing and sharing data and preservation. Significant differences in the frequency and location of codes were identified by program type and Carnegie Classification.Conclusions:Nursing doctoral program handbooks primarily address collecting and analyzing data during student projects. Findings suggest limited education about, and inclusion of, DM life cycle content, especially within DNP programs. Collaboration between nursing faculty and librarians and nursing and library professional organizations is needed to advance the adoption of DM best practices for preparing students in their future roles as clinicians and scholars.