SYMPOSIA PAPER Published: 01 January 1993
STP25568S

3-D Video Motion Analysis on the Slope—A Practical Way to Analyze Motion Patterns in Alpine Skiing

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A detailed knowledge of motion patterns in sport is the basis for injury prevention, as well as performance enhancement. During the last two decades, enormous progress has been made in the field of video technology (U-matic, VHS, SVHS), that is now an alternative to 16 mm film. The goal of this study is to use a new SVHS video analysis system (Peak Performance System) on the slope for analyzing three different skiing techniques and revealing the practicality, accuracy and reliability of such a technique under extreme field conditions. Demonstrating each of the techniques, three different skiers were measured ten times, by using a 3-D camera setup with three synchronized video cameras. Sampling rate was set to 50 Hz. The calibration was done by using a theodolite and a calibration frame (cube) for smaller fields of view. The total time to set up the whole field was found to be one hour. In order to have a large enough picture to digitize, we chose only one turn to be in the field of view.

We found significant differences between the techniques in vertical acceleration, upper body rotation and angular displacement of the knee joint. By means of a computer animated stick figure, we could optically demonstrate the differences after rotating the figure into the proper position. Splitting the screen in up to four quadrants allowed comparison of the different techniques on screen.

The results lead to the conclusion that such a technique is a reliable, practical tool to establish a risk discrimination for the knee between different techniques. In addition there is valuable information that can be used to enhance the performance of the skier as well as lead to injury prevention.

Author Information

Schaff, P
Institute for Biomechanical Analysis and Interdisciplinary Studies (BASIS), TUV Product Service GmbH, Munich, Germany
Hauser, W
Institute for Biomechanical Analysis and Interdisciplinary Studies (BASIS), TUV Product Service GmbH, Munich, Germany
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Details
Developed by Committee: F27
Pages: 169–176
DOI: 10.1520/STP25568S
ISBN-EB: 978-0-8031-5237-3
ISBN-13: 978-0-8031-1494-4