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1
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The Hierarchical Structure of Selected Morphological and Motoric Variables in Ski Jumping

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Jošt B.
Human Movement
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2010
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vol. 11
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issue 2
124-131
EN
Purpose. The main purpose of the present research paper was to establish a hierarchical factor structure in a selected sample of morphological and motor variables of ski jumpers; such variables are base constituents of the potential performance model in ski jumping. Basic procedures. The subject sample was Slovene ski jumpers older than 15 years (n = 72), tested in May 2008. The research was done on a selection of 41 variables (12 basic morphological ones, seven from a special morphological index, 10 basic motoric ones and 12 special dynamic variables of take-off power). Main findings. Through factor analysis in the first phase, nine factors were excluded from the manifest variables of first orders: 1. Factor of velocity power (34.9% of variance); 2. Factor of longitudinal body dimensions (17.2% of variance); 3. Factor of morphological index of flight aerodynamics (12.2% of variance); 4. Factor of morphological index of take-off (7.3% of variance), 5. Factor of push-off explosive power (5.0% of variance), 6. Factor of informatic component of motorics (3.5% of variance); 7. Factor of specific morphological index of thigh dimensions (3.1% of variance), 8. Factor of transversal dimensions of body (2.4% of variance), 9. Factor of flexibility of hips (2.2% of variance). All nine factors of the first order explained 88% of variance of manifest variables. On the basis of configuration of nine factors of the first order in the second phase, four components were excluded from the second order with 62.7% of total variance. The first was component of specific take-off movement (22.9% of variance), followed by component of thigh dimension (14.5% of variance), then component of specific flight potential (13.0% of variance) and finally component of basic morphology (12.1% of variance). On the third level of factor analysis, two general factors of ski jumpers with 57.1% of total variance were found. The first was the general factor of specific movement of ski jumpers (29.8% of variance) and second the general factor of morphology (27.7% of variance). Conclusions. The research confirms the main hypothesis that hierarchical latent factor structures of manifest motor and morphological variables exist. The independent primary factors of the first order are crucial for understanding the latent dimensions of the potential performance model on the second and third level. This factor shows the structure between manifest dimensions more clearly and their relations are more understandable.
2
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Kinematic Analysis of the Take-Off and Start of the Early Flight Phase on a Large Hill (HS-134 m) during the 2009 Nordic World Ski Championships

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Janura M., Cabell L., Svoboda Z., Elfmark M., Zahalka F.
Journal of Human Kinetics
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2011
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vol. 27
5-16
EN
The take-off is often considered the most significant and difficult phase of a ski jump. Thus, the purpose of this study was to compare three groups of ski jumpers representing different skill levels during the execution of the take-off and start of the early flight phase in ski jumping. A total of 30 athletes, recruited from competitors performing ski jumps on an HS-134 m jumping hill, were categorized into three groups based on jump-length execution. Two-dimensional (2-D) kinematic data were collected from the lower extremities, trunk, and skis of the ski jumpers. Findings indicated that the ski jumpers with shorter jump length demonstrated significantly smaller in-run velocity (p < .05), while the elite and mediocre level ski jumpers exhibited a significantly faster shift of the thigh at the transition from take-off into the early flight of the jump (p < .05) than did the low-level ski jumpers. In addition, the centre of body mass (CoM) of the elite group shifted significantly more forward over the skis (p < .01) than did that of the other two groups. Finally, interindividual differences existed among ski jumpers at similar performance levels. The largest coefficients of variation (CVs) were found for the position changes of the trunk and shank behind the jumping hill edge.
3
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Kinematic Structure at the Early Flight Position in Ski Jumping

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Vodičar J., Čoh M., Jošt B.
Journal of Human Kinetics
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2012
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vol. 35
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issue 1
35-45
EN
The purpose of our research was to establish the variability of correlation between the length of the jumps and selected multi-item kinematic variables (n=9) in the early flight phase technique of ski jumping. This study was conducted on a sample of elite Slovenian ski jumpers (N=29) who participated in the experiment on a jumping hill in Hinterzarten, Germany (HS95m) on the 20th of August, 2008. The highest and most significant correlations (p=0.01) with the length of the ski jump were found in the multi-item variable height of flying, which was also expressed with the highest level of stability of the explained total variance (TV) on the first factor (TV=69.13%). The most important characteristic of the aerodynamic aspect of early flight was the variable angle between the body chord and the horizontal axis with significantly high correlations (p<0.05). The stability of that aerodynamic factor was very high (TV=65.04%). The results were essentially similar for the multi-item variable angle between left leg and the horizontal axis (TV=61.88%). The rest of the multi-item kinematic variables did not have significant correlations with the multi-item variable length of jump. Only two more variables, the angle between the upper body and the horizontal plane (TV=53.69%), and the angle between left ski and left leg (TV=50.13%), had an explained common variance on the first factor greater than 50% of total variance. The results indicated that some kinematic parameters of ski jumping early flight technique were more important for success considering the length of the jump.
4
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Kinematic Chains in Ski Jumping In-run Posture

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Janurová E., Janura M., Cabell L., Svoboda Z., Vařeka I., Elfmark M.
Journal of Human Kinetics
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2013
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vol. 39
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issue 1
67-73
EN
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.
5
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The Factor Structure of Chosen Kinematic Characteristics of Take-Off in Ski Jumping

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Vodicar J., Jost B.
Journal of Human Kinetics
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2010
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vol. 23
37-45
EN
With a sample of 29 of the best Slovenian ski jumpers, a research project was carried out with the purpose of determining the structure relation of chosen dynamic and kinematic variables during the take-off of ski jumpers. The experiment was performed in August 2008 on the jumping hill in Hinterzarten, Germany (K=95m). The subjects jumped seven times without breaks between rounds. The analysis was done on variables that determine the technique of take-off in ski jumping (in-run velocity - km/h, vertical take-off velocity - m/s, precision of take-off - cm). The criteria variable was the length of the jump (m). The variability of the long distance of the jumps was significantly strong. The reliability of all used multi-item variables was high and satisfactory in most variables (in-run velocity - 0.98, vertical take-off velocity - 0.98, precision of take-off - 0.85, length of the jump - 0.95). The factor analysis produced an independent latent structure (explanation of variance = 93.3%) of five specific factors (1. in-run velocity connected to distance jumped (39.8 % of VAR.), 2. vertical take-off velocity strongly connected to distance jumped (26.0 % of VAR.), 3. precision of take-off partly connected to distance jumped (14.9 % of VAR.), 4. precision of take-off in the 7th round (6.7 % of VAR.), 5. precision at take-off in the 4th round (5.7 % of VAR.). The present factor structure confirms the hypothetical model of three independent motor tasks to be optimally realized in the take-off of the ski jumper. Criteria variables influencing the length of jumps were mainly associated with the first two factors, which confirm the basic hypothesis that the length of the jump reflects the overall output quality of the first two factors. The accurancy factor of take-off affects the length of the jumps indirectly and latently through these two fundamental factors.
6
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Lost in Translation: Heidegger and Ski Jumping in Slovenia

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Kreft L.
Physical Culture and Sport. Studies and Research
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2010
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vol. 49
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issue 1
13-20
EN
Heidegger developed his non-concept Gelassenheit after World War II. Its meaning remains uncertain and controversial, something different from notions of everyday conversation. In Slovene, however, it has been translated as sproščenost, which is parallel to English ‘relaxedness’, thus producing hybridity between notions of relaxedness, relaxation and releasement, which is, together with letting-go, a proper English translation of Gelassenheit.This hybridity was (ab)used for political slogans during the 2004 elections, when Heidegger's term was repeated on and on, until it entered popular discourse as well as other domains such as the economy, culture, and media. This phenomenon was examined by Boris Vezjak in The Relaxed Ideology of Slovenes (The Peace Institute, Ljubljana 2007). Relaxedness-releasement entered sport jargon as well, but Vezjak's book did not cover this field. At first abundant, this term more or less disappeared later. With one exception: in ski jumping, where it became one of the main words used to explain what was missing from Slovenian ski jumping during 2004-2009 period. In Slovenia, ski jumping is a national sport, and the absence of excellence during this long period created additional pressures on athletes and the whole ski jumping commonwealth.To examine the numerous cases where releasement was used to explain what is wrong with ski jumpers, or what they finally achieved in rare examples of success during that period, the only Slovene sport daily, "Ekipa" (The Team), was consulted for research. This study revealed that releasement was indeed lost in translation, appearing in ads as a signifier without any certain signified, and functioning as a je-ne-sais-quoi of sport performance and excellence. Through cases of repeated use of releasement as mystical and at the same time scientific (instead of relaxation) and colloquial notion (which is relaxedness, even carelessness), we get at inoculation of kinesiological mechanicism and psychological technique with philosophical mysticism.
7
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Configurations of the Graf-Boklev (V-Style) SKI Jumper Model and Aerodynamic Parameters in a Wind Tunnel

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Maryniak J., Ładyżyńska-Kozdraś E., Tomczak S.
Human Movement
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2009
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vol. 10
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issue 2
130-136
EN
The paper discusses the results of wind tunnel tests for different angular configurations (φ1 and φ2) of a V-style (Graf-Boklev style) ski jumper model. The range of tested angles of attack was α = -10, 20, 30, 40 (deg), depending on a configuration. The configurations of the Graf-Boklev style ski jumper model were compared with the classic parallel style of ski jumping with the ski-opening angle λ = 0. Kl as a configuration for the parallel style of ski jumping was used as the reference configuration for other configurations with different ski-opening angles, i.e. λ = 0, 15, 25, 45 (deg). The results obtained have been presented graphically as aerodynamic parameters within a specific angle of attack.
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