The Factor Structure of Chosen Kinematic Characteristics of Take-Off in Ski Jumping

• Authors: Janez Vodicar , Bojan Jost
• Languages of publication: EN

Abstracts

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.

Keywords

EN

ski jumping; factor structure; kinematics of take-off

• Publisher: De Gruyter Open
• Journal: Journal of Human Kinetics
• Year: 2010
• Volume: 23
• Pages: 37-45

Dates

published

1 - 1 - 2010

online

24 - 5 - 2010

Contributors

author

Janez Vodicar

• Faculty of Sport, University of Ljubljana

author

Bojan Jost

• Faculty of Sport, University of Ljubljana

References

• Arndt A., Bruggemann P. G., Virmavirta M. & Komi P. Techniques Used by Olympic Ski Jumpers in the Transition From Takeoff to Early Flight. J Appl Biomech, 1995; 11: 224-237.
• Ettema G.J, Braten S. & Bobbert M. F. Dynamics of the In-Run in Ski Jumping: A simulation Study. J Appl Biomech, 2005; 21, 247-259.
• Jošt B. Performance success in ski-jumping related to vertical take-off speed. Biomechanics in Sport XI. Proceedings of the XIth Symposium of the International Society of Biomechanics in Sports (eds. J. Hamill et al.), 1993; Amherst, Ma, USA.
• Jost B., & Strojnik V. Ski jump parameters' measurement reliability on a tensiometric force plate and specific measurement plate. Kinesiologia Slovenica 1992; 1 (1), 33-38.
• Komi P. V. & Virmavirta M. Ski-jumping take-off performance: Determining factors and methodological advances. In: Proceedings book of the First International Congress on Skiing and Science, St. Chrisoph a. Arlberg, Austria, January 7-13, 1996 (pp. 3-26). Cambridge: 1997; Cambridge University Press.
• Lurija A. R. Osnovi neuropsihologije. Beograd: Nolit, 1976.
• Medved I. Povezanost izbranih spremenljivk odskoka smučarja skakalca z dolžino skoka - diplomsko delo (Correlation between chosen variables of takeoff and longines of Skijumps- diploma work). Ljubljana: Fakulteta za šport. 2007.
• Sasaki T., Tsunoda K., Uchida E., Hoshino H. & Ono M. Joint Power Production in Take-Off Action during Ski-Jumping. In: (Muller, E., Schwameder, H., Kornaxl, E., Raschner, C., eds.). Proceedings of the forst International Congress on Skiing and Science St. Chrisoph a. Arlberg, Austria. January 1997; 7-13, 1996: 49-60.
• Schmolzer B. & Muller W. Individual flight styles in ski jumping: results obtained during Olympic Games competitions. J Biomech, 2004; 38 (5), 1055-1065.
• Schwameder H., Muller E. Biomechanics in Ski jumping: A Review. European Journal of Sport Science, 2001; 1: 1-16.
• Vaverka, F. Biomechanika skoku na lyžich. UP Olomouc 1987.
• Vaverka F., Janura M., Elfmark M., Salinger J. Inter- and intra-individual variability of the ski-jumper's take-off. In: Proceedings book of the First International Congress on Skiing and Science, St. Chrisoph a. Arlberg, Austria, January 7-13, 1996; (pp. 61-71). Cambridge: Cambridge University Press. 1997.
• Virmavirta M. & Komi P. V. The Take-off Forces in Ski Jumping. International Journal of Sport Biomechanics, 1989; 5: 248-257.[WoS]
• Virmavirta M. & Komi P. V. Measurement of take -off forces in ski jumping - Part 1. Scand J Med Sci Sports, 1993a; 3: 229-236.
• Virmavirta M. & Komi P. V. Measurement of take-off forces in ski jumping - Part II. Scand J Med Sci Sports, 1993b; 3: 237-243.
• Virmavirta M. & Komi P. V. Take-off analysis of a champion ski jumper. Coaching and Sport Science Journal, 1994; 1 (1): 23-27.
• Virmavirta, M., Isolehto, J., Komi, P., Brüggemann, G. P., Müller, E, Schwameder, H. Characteristics of the early flight phase in the Olympic ski jumping competititon. J Biomech 2005; 38, 2157 - 2163.

Identifiers

DOI

10.2478/v10078-010-0005-6