Kinematic Characteristics of the Ski Jump Inrun: A 10-Year Longitudinal Study

2010 ◽  
Vol 26 (2) ◽  
pp. 196-204 ◽  
Author(s):  
Miroslav Janura ◽  
Lee Cabell ◽  
Milan Elfmark ◽  
František Vaverka
Keyword(s):  
Average Velocity ◽  
Joint Angles ◽  
Kinematic Parameters ◽  
Contributing Factors ◽  
World Cup ◽  
Kinematic Data ◽  
Straight Path ◽  
Body Segments ◽  
Ski Jumping ◽  
The World

The athlete’s inrun position affects the outcome for take-off in ski jumping. The purpose of this study was to examine the kinematic parameters between skiers’ adjacent body segments during their first straight path of the inrun. Elite ski jumpers participated in the study at the World Cup events in Innsbruck, Austria, during the years 1992 through 2001. A video image was taken at a right angle to the tracks of the K-110 (meter) jumping hill. Kinematic data were collected from the lower extremities and trunk of the athletes. Findings indicated that jumpers had diminished ankle and knee joint angles and increased trunk and hip angles over the 10 years. In recent years, the best athletes achieved a further length of their jumps, while they experienced slower inrun average velocity. These results are perhaps explained by several possible contributing factors, such as new technique of the jumper’s body kinematics, advancements in equipment technology, and somatotype of the jumpers.

scholarly journals Kinematic Chains in Ski Jumping In-run Posture

2013 ◽  
Vol 39 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Eva Janurová ◽  
Miroslav Janura ◽  
Lee Cabell ◽  
Zdeněk Svoboda ◽  
Ivan Vařeka ◽  
...  
Keyword(s):  
Kinematic Chain ◽  
Coefficient Of Determination ◽  
Ground Contact ◽  
Longitudinal Assessment ◽  
Joint Angles ◽  
World Cup ◽  
Kinematic Data ◽  
Kinematic Chains ◽  
Ski Jumping ◽  
Adjacent Segments

Abstract The concept of kinematic chains has been systematically applied to biological systems since the 1950s. The course of a ski jump can be characterized as a change between closed and open kinematic chains. The purpose of this study was to determine a relationship between adjacent segments within the ski jumper’s body’s kinematic chain during the in-run phase of the ski jump. The in-run positions of 267 elite male ski jumpers who participated in the FIS World Cup events in Innsbruck, Austria, between 1992 and 2001 were analyzed (656 jumps). Two-dimensional (2-D) kinematic data were collected from the bodies of the subjects. Relationships between adjacent segments of the kinematic chain in the ski jumper’s body at the in-run position are greater nearer the chain’s ground contact. The coefficient of determination between the ankle and knee joint angles is 0.67. Changes in the segments’ positions in the kinematic chain of the ski jumper’s body are stable during longitudinal assessment. Changes in shank and thigh positions, in the sense of increase or decrease, are the same.

Fair compensation for gate and wind conditions in ski jumping – estimated from competition data using a mixed model

2015 ◽  
Vol 11 (4) ◽  
Author(s):  
Magne Aldrin
Keyword(s):  
Mixed Model ◽  
Compensation System ◽  
The Other ◽  
World Record ◽  
World Cup ◽  
Ski Jumping ◽  
Compensation Factor ◽  
The World ◽  
Fair Compensation ◽  
Olympic Sport

AbstractSki jumping is a Winter Olympic sport where the athletes try to fly as far as possible with the best possible style on a ski jumping hill. The best athletes may achieve distances around 100 m on the smallest hills and up to 251.5 m (the world record) on a flying hill. The length of a ski jump is affected by the gate from which the jumpers start, where higher gates give higher speed and therefore longer jumps. Wind conditions are also important, head winds tend to give longer jumps and tail winds tend to give shorter jumps. To ensure relatively fair conditions during competitions, a system including gate and wind compensations was introduced from January 2010. If the conditions change considerably during a round, the jury can change the gate number to avoid too long or too short jumps, and the athlete is then given a compensation (positive or negative). Furthermore, the athletes are given a compensation for the wind conditions during their jump. In this paper, the fairness of this compensation system is investigated by an analysis of the results from 80 ski jumping competitions for men arranged in the World Cup, World Championships and Olympics in the 2011/2012, 2012/2013 and 2013/2014 seasons. The analysis is based on a mixed model. I found that the present compensation for gate number is reasonably fair, but with a tendency for 10% over-compensation. On the other hand, I estimate that the present compensation factor for head winds should be increased by 48% (95% CI 40–57%) and for tail winds by 22% (95% CI 16–30%) to fully compensate for wind conditions.

Career Counselling Effectiveness and Contributing Factors

2020 ◽  
Author(s):  
Susan C. Whiston
Keyword(s):  
Career Choice ◽  
Significant Influence ◽  
Empirical Support ◽  
Effect Sizes ◽  
Career Counselling ◽  
Contributing Factors ◽  
Considerable Evidence ◽  
Effective Strategies ◽  
The World ◽  
Meta Analyses

This chapter explores the research related to whether career counselling is effective for individuals with vocational issues. In particular, there is considerable empirical support for career counselling related to career choice issues and searching for employment. Hence, practitioners can use this evidence to convince administrators, policymakers, parents, students, and other constituencies of the worth of career counselling. In addition, the chapter provides empirical evidence that practitioners can use to improve their effectiveness in working with people with career issues. This discussion mainly focuses on the results from older and newer meta-analyses regarding the ingredients that have a significant influence on effect sizes or the critical ingredients in career counselling. For example, there is considerable evidence that support from individuals, including the counsellor, may play an important role in the effectiveness of career counselling. Other factors that contribute to effective practice are also identified and discussed. The chapter further explores the need for additional research that addresses the most effective methods for providing career counselling. As the world of work becomes increasingly complex, it is important that researchers continue to explore the most effective strategies for assisting people in finding satisfying, meaningful, and productive work.

GOAALLL!: Using sentiment in the world cup to explore theories of emotion

2017 ◽  
Vol 65 ◽  
pp. 58-65 ◽  
Author(s):  
Gale M. Lucas ◽  
Jonathan Gratch ◽  
Nikolaos Malandrakis ◽  
Evan Szablowski ◽  
Eli Fessler ◽  
...  
Keyword(s):  
World Cup ◽  
The World

Collective Decision-making: FIFA from the Perspective of Public Choice

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Florian Follert ◽  
Lukas Richau ◽  
Eike Emrich ◽  
Christian Pierdzioch
Keyword(s):  
Decision Making ◽  
Public Choice ◽  
Choice Theory ◽  
Collective Decision ◽  
Public Confidence ◽  
Collective Decision Making ◽  
Public Choice Theory ◽  
World Cup ◽  
The World ◽  
Selection Of

AbstractVarious scandals have shaken public confidence in football's global governing body, Fédération Internationale de Football Association (FIFA). It is evident that decision-making within such a collective provides incentives for corruption. We apply the Buchanan-Tullock model that is known from Public Choice theory to study collective decision-making within FIFA. On the basis of this theoretical model, we develop specific proposals that can contribute to combating corruption. Three core aspects are discussed: the selection of the World Cup host, transparency in the allocation of budgets, and clear guidelines for FIFA officials and bodies with regard to their rights and accountability. Our insights can contribute to a better understanding of collective decision making in heterogenous groups.

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