Technical possibilities for optimising the ski-binding-boot functional unit to reduce knee injuries in recreational alpine skiing     

Veit Senner  Frank I. Michel  Stefan Lehner  Othmar Brügger 《Sports Engineering》2013,16(4):211-228

This review study focuses on knee injuries in recreational alpine skiing. The objectives of this study were (1) to provide selected knowledge derived from current and past knee injury epidemiology; (2) to outline the most important knee injury mechanisms; and (3) to review and discuss how modifications of the skiing equipment might alleviate the risk of knee injuries. This review represents the essence of a comprehensive research report and considers the content of more than 230 scientific papers, further “grey literature”, patents, international standards and other publications. Knee injuries are the most frequent injuries in alpine skiing and their incidence rate remained high despite a decline of the incidence of other skiing injuries in recent years. Women have a higher knee injury risk, but age and tiredness appear not to be significant factors. Apart from the commonly described injury mechanisms “phantom foot” and “boot-induced anterior drawer” other more sophisticated injury categorisations are given. The ski radius, the ski length and the standing height on the ski may be relevant ski parameters. For the binding, the release mechanisms in different mechanical degrees of freedom, the impact tolerance and the maintenance frequency are discussed. In the ski boot, the height of the upper, the boot liner, the shaft stiffness, and the position on the ski may play a role. The biggest challenge, but probably also the biggest opportunity for a reduction of knee injury rates seems to be the development of a mechatronic binding. The current strategies to develop these types of bindings are explained and illustrated by one example. Some of the possible parameters which may be essential for the necessary control algorithms are described. Finally, considerations regarding the strategic and operational implication of the analysed technical measures are given.  相似文献   

Development of a test device for testing soccer boots under gamerelevant highrisk loading conditions     

T. Grund  V. Senner  K. Grube 《Sports Engineering》2007,10(1):55-63

Soccer boots are the most important piece of equipment used by a soccer player. They have been improved from heavy bold leather shoes to lightweight aerodynamic designer objects. As traction is one of the key factors of performance, industry experiments with new stud designs, hoping to improve traction behaviour in the different directions. However, excessive traction may contribute to the occurrence of non-contact injuries of the anterior cruciate ligament (ACL). Therefore, many researchers have investigated the shoe-surface interaction of studded boots with mechanical test devices. As yet, a final conclusion regarding correlation between stud design and ACL injuries has not been obtained. Most of the current test devices do not test the soccer boots under game-relevant loading conditions. A new approach has been taken in order to overcome this limitation. In the first step, real ACL injury situations were analysed in detail. The results of this analysis were then used as input data for a multi-body computer model of the human body, to calculate internal forces at the injured leg. Based on this data, a new test device, the TrakTester, was developed including an artificial lower leg with a replica human ankle joint. This paper presents details of the development of the new traction test device and gives an overview of the research options the TrakTester may provide for the future.  相似文献   

Simulation of puck flight to determine spectator safety for various ice hockey board heights     

H. Böhm  C. Schwiewagner  V. Senner 《Sports Engineering》2007,10(2):75-85

The boards of ice hockey rinks are equipped with protective glass to prevent the spectators from being hit by the puck. According to international rules, the minimum height of the board with protective glass is 197 cm. This is not high enough to protect the spectators from puck-related injuries, and severe accidents have occurred in the past. This study investigates what increase in the height of the safety glass is necessary to reduce the risk of severe puck-related injuries to spectators. Puck flights towards the safety board are simulated, based on initial take-off conditions of the puck, by top-level players. The simulations show that increasing the security glass from a board height without any protective glass of 117 cm to a total band height of 380 cm will lower the relative frequency of shots with a potential to hit a spectator by 80%. The maximum velocity of such dangerous shots was only slightly decreased from 28.4 m s⁻¹ to 25.2 m s⁻¹ for the same difference in band height. However, the reduced number of dangerous shots does not protect the spectators completely from injuries. The simulation model suggests that a safety wall height of 10.8 m leads to a 100% reduction in all outgoing shots.  相似文献   

'So few fat ones grow old': diet, health, and virtue in the golden age of rising life expectancy     

Veit HZ 《Endeavour》2011,35(2-3):91-98

Life expectancy and chronic disease rates both rose dramatically in the United States during the first third of the twentieth century. As a result of this concurrence, Americans in this era increasingly thought about things they could do to extend their own lives, especially eating less, exercising more, and limiting stress, all factors thought to reduce chronic disease. New recognition of the correlation between daily physical habits and long lives made longevity look like a sign of virtue. At the same time, amidst discussions about the relationship between individual longevity and national vitality, this correlation also contributed to Americans' moralization of diet, exercise, and emotional self-control.  相似文献   

What moderates the accuracy of ease of learning judgments?     

Andreas Jemstedt  Veit Kubik  Fredrik U. Jönsson 《Metacognition and Learning》2017,12(3):337-355

When people begin to study new material, they may first judge how difficult it will be to learn. Surprisingly, these ease of learning (EOL) judgments have received little attention by metacognitive researchers so far. The aim of this study was to systematically investigate how well EOL judgments can predict actual learning, and what factors may moderate their relative accuracy. In three experiments, undergraduate psychology students made EOL judgments on, then studied, and were tested on, lists of word-pairs (e.g., sun – warm). In Experiment 1, the Goodman-Kruskal gamma (G) correlations showed that EOL judgments were accurate (G = .74) when items varied enough in difficulty to allow for proper discrimination between them, but were less accurate (G = .21) when variation was smaller. Furthermore, in Experiment 1 and 3, we showed that the relative accuracy was reliably higher when the EOL judgments were correlated with a binary criterion (i.e., if an item was recalled or not on a test), compared with a trials-to-learn criterion (i.e., how many study and test trials were needed to recall an item). In addition, Experiments 2 and 3 indicate other factors to be non-influential for EOL accuracy, such as the task used to measure the EOL judgments, and whether items were judged sequentially (i.e., one item at a time in isolation from the other items) or simultaneously (i.e., each item was judged while having access to all other items). To conclude, EOL judgments can be highly accurate (G = .74) and may thus be of strategic importance for learning. Further avenues for research are discussed.  相似文献   

Femoral indicator injection for transpulmonary thermodilution using the EV1000/VolumeView®: do the same criteria apply as for the PiCCO®?     

Wolfgang Huber  Veit Phillip  Josef Höllthaler  Caroline Schultheiss  Bernd Saugel  Roland M. Schmid 《Journal of Zhejiang University. Science. B》2016,17(7):561-567

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Effects of different weight loss intervention programmes in health clubs – an observational multicenter study     

Markus Wanjek  Veit Senner  Friederike Scharhag-Rosenberger  Martin Halle 《European Journal of Sport Science》2016,16(7):859-867

This study aimed at comparing the effectiveness of three lifestyle intervention programmes in health clubs “exercise only” (E), “exercise plus nutritional counselling” (E?+?NC), and “exercise plus weight loss program” (E?+?WLP) on weight loss under real-life conditions. An observational multicenter study including 788 overweight/obese new customers of 95 health clubs in Germany was performed. Participants chose E (n?=?512, 38?±?14?year, BMI 30.4?±?4.7?kg/m²), E?+?NC (n?=?179, 42?±?14?year, BMI 31.7?±?4.5?kg/m²), or E?+?WLP (n?=?97, 40?±?11?year, BMI 31.6?±?5.1?kg/m²). Anthropometric data, energy expenditure, and energy intake were assessed at baseline and after 3 months. All groups significantly reduced body weight (E: ?1.5?±?2.9?kg, E?+?NC: ?3.4?±?3.6?kg, E?+?WLP: ?5.5?±?4.3?kg, p?p?p?相似文献   

Academic freedom in germany before and after 1933     

Fritz Veit 《Peabody Journal of Education》2013,88(1):36-44

A Nation at Risk (NAR; National Commission on Excellence in Education, 1983) had a tremendous impact on what schools do and has since spawned other reforms that attest to the report's ongoing influence. Coming in the wake of a decade of economic stagnation and import pressures from overseas producers, the authors of NAR blamed these problems on schools. In this article, we show that there was little justification for this conclusion, then or now. Although education clearly plays a role in the economy, it is only one of many factors. We find little evidence that there is a large or growing mismatch between worker skills and employer demands. Moreover, the American work force and economy continue to be among the most productive in the world. We should improve our schools and our economy, but real improvement will only occur when their problems are correctly diagnosed.  相似文献