Effects of muscle-tendon length on joint moment and power during sprint starts

The aim of this study was to examine the effects of muscle-tendon length on joint moment and power during maximal sprint starts. Nine male sprinters performed maximal sprint starts from the blocks that were adjusted either to 40 degrees or 65 degrees to the horizontal. Ground reaction forces were recorded at 833 Hz using a force platform and kinematic data were recorded at 200 Hz with a film camera. Joint moments and powers were analysed using kinematic and kinetic data. Muscle - tendon lengths of the medial gastrocnemius, soleus, vastus medialis, rectus femoris and biceps femoris were calculated from the set position to the end of the first single leg contact. The results indicated that block velocity (the horizontal velocity of centre of mass at the end of the block phase) was greater (P < 0.01) in the 40 degrees than in the 65 degrees block angle condition (3.39 +/- 0.23 vs. 3.30 +/- 0.21 m . s(-1)). Similarly, the initial lengths of the gastrocnemius and soleus of the front leg in the block at the beginning of force production until half way through the block phase were longer (P < 0.001) in the 40 degrees than in the 65 degrees block angle condition. The initial length and the length in the middle of the block phase were also longer in the 40 degrees than in the 65 degrees block angle condition both for both the gastrocnemius (P < 0.01) and soleus (P < 0.01-0.05) of the rear leg. In contrast, the initial lengths of the rectus femoris and vastus medialis of the front leg were longer (P < 0.05) in the 65 degrees than in the 40 degrees block angle condition. All differences gradually disappeared during the later block phase. The peak ankle joint moment (P < 0.01) and power (P < 0.05) during the block phase were greater in the 40 degrees than in the 65 degrees block angle condition for the rear leg. The peak ankle joint moment during the block phase was greater (P < 0.05) in the 40 degrees block angle for the front leg, whereas the peak knee joint moment of the rear leg was greater (P < 0.01) in the 65 degrees block angle condition. The results suggest that the longer initial muscle-tendon lengths of the gastrocnemius and soleus in the block phase at the beginning of force production contribute to the greater peak ankle joint moment and power and consequently the greater block velocity during the sprint start.     

The Multiple Faces of Visual Arts Education

This article identifies recent, mainly Nordic, research approaches to visual arts education. A concept map was developed as a heuristic tool in order to highlight salient traits and blind spots. Contemporary research typically has its origin either in education or in the art world, with an emphasis either on art as language or on art as text. These two dimensions were used to organise the studies and to select representative exemplars in different domains. The framework helped to chart the knowledge base of, and research approaches to, visual arts education. However, the result of blending subject matter and pedagogy tended to be a ‘mixture’ of viewpoints rather than emerging domains of subject‐specific pedagogical knowledge (Lee Shulman: an ‘amalgam’).     

Correction to: The influence of SES,cognitive, and non-cognitive abilities on grades: cross-sectional and longitudinal evidence from two Swedish cohorts

It is well established that socioeconomic status, cognitive ability, and non-cognitive abilities such as self-efficacy are substantially associated with academic achievement. However, the specific relationships of these variables remain a relatively unexplored topic in regard to more recent and representative samples. The current study examined such relations by taking advantage of two cohorts (total N = 12,315) of Swedish students at the elementary (Grade 6) and lower-secondary school levels (Grade 8) in the compulsory school. The regression models showed that all three variables explained a substantial portion of grade variance, with cognitive ability having the strongest relationship, followed by non-cognitive abilities, and SES. Longitudinal associations, which accounted for previous academic achievement, showed that the three variables did still explain a substantial amount of grade variance.

     

Technical analysis of a Central Asian wall painting detached from a Buddhist cave temple on the northern Silk Road

A great number of Central Asian wall paintings, archeological materials, architectural fragments, and textiles, as well as painting fragments on silk and paper, make up the so called Turfan Collection at the Asian Art Museum in Berlin. The largest part of the collection comes from the Kucha region, a very important cultural center in the third to ninth centuries. Between 1902 and 1914, four German expeditions traveled along the northern Silk Road. During these expeditions, wall paintings were detached from their original settings in Buddhist cave complexes. This paper reports a technical study of a wall painting, existing in eight fragments, from the Buddhist cave no. 40 (Ritterhöhle). Its original painted surface is soot blackened and largely illegible. Grünwedel, leader of the first and third expeditions, described the almost complete destruction of the rediscovered temple complex and evidence of fire damage. The aim of this case study is to identify the materials used for the wall paintings. Furthermore, soot deposits as well as materials from conservation interventions were of interest. Non-invasive analyses were preferred but a limited number of samples were taken to provide more precise information on the painting technique. By employing optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, micro X-ray fluorescence spectroscopy, X-ray diffraction analysis, and Raman spectroscopy, a layer sequence of earthen render, a ground layer made of gypsum, and a paint layer containing a variety of inorganic pigments were identified.     

Ideology or reality? The awareness of educational aims and activities amongst German and Norwegian participants of the first summer and winter Youth Olympic Games

This paper explores the awareness of the young German and Norwegian participants in the Youth Olympic Games (YOG) of the additional educational mission of this new event, implemented by the International Olympic Committee. Among the questions considered are whether the nature of the event contradicts its claimed intention to focus on both competition and education. Data were collected through a set of interviews with young German and Norwegian athletes at the Singapore YOG in the summer of 2010 and the Innsbruck YOG in the winter of 2012. The findings revealed (1) a focus on elite sport by athletes and their coaches, while the educational aims were considered secondary; (2) that it was problematic for the young participants to focus on education in a high-performance event. The overall conclusion was that the YOG have had only limited success in achieving the educational ambitions of the Olympic Movement.     

‘The Sole Anti-Democratic Federation in the Entire Olympic Movement’: Early International Association of Athletics Federations Development Initiatives Between Commercialization and Democratization, 1974–1987

Abstract

Studies on the development of Olympic Solidarity as a tool of the International Olympic Committee (IOC) to enable National Olympic Committees of developing countries access to resources and influence in the Olympic Movement exist. However, historical scholarship has relatively neglected the development of aid programs by International Federations to explain how they made use of resources to gain influence in international sport politics. Based on extensive multi-national and multi-lingual archival research in the archives of the International Association of Athletics Federation (IAAF) and the German Sport University Cologne, this article explores the establishment and development of the IAAF‘s Technical Aid Program, which had been installed in 1974. Referencing a large amount of previously unknown protocols and written correspondence, the paper critically discusses the IAAF‘s development activities in light of two parallel occurring processes that shaped the federation’s character in the 1970s and 1980s decisively: its increasing commercialization and its path towards democratization in its voting system. It is argued that the IAAF development programs served as a tool to enforce commercial and sport political interests whilst the nature of support remained without clear guidance until the mid-1980s.     

PÄdagogische Zeitschriften Westdeutschlands

Ohne Zusammenfassung     

Mathematics and mathematics education: Content and people, relation and difference

A broad view of mathematics education takes it as the study of how people learn and do mathematics. Starting with this view, the actual and potential relationships of mathematics education as are search discipline to mathematics as a field of knowledge and activity and to the mathematicians carrying out that activity are analyzed. This leads to the picture of a gulf between the two scientific communities which are based in different cultures of thinking and research. A (meta-)study of mathematics and all its facets termed here mathematicology is proposed. It could serve as common ground for cooperative studies by mathematicians and mathematics educators. Thereby the gulf will not necessarily become narrower but abridge over the differences and mutual misunderstandings could be built.     

Wandel in der Fremdsprachenpolitik der DDR

Ohne Zusammenfassung