@article{ref1,
title="Analysis of a severe head injury in World Cup alpine skiing: a case report",
journal="Medicine and science in sports and exercise",
year="2014",
author="Yamazaki, Junya and Gilgien, Matthias and Kleiven, Svein and McIntosh, Andrew S. and Nachbauer, Werner and Muller, Erich and Bere, Tone and Bahr, Roald and Krosshaug, Tron",
volume="47",
number="6",
pages="1113-1118",
abstract="Traumatic brain injury (TBI) is the leading cause of death in alpine skiing. It has been found that helmet use can reduce the incidence of head injuries between 15% and 60%. However, knowledge on optimal helmet performance criteria in World Cup alpine skiing is currently limited due to lack of biomechanical data from real crash situations. <br><br>PURPOSE: This study aimed to estimate impact velocities in a severe TBI case in World Cup alpine skiing. <br><br>METHODS: Video sequences from a TBI case in World Cup alpine skiing were analyzed using a Model-Based Image Matching (MBIM) technique. Video sequences from four camera views were obtained in full high definition (1080p) format. A 3D model of the course was built based on accurate measurements of piste landmarks and matched to the background video footage using the animation software Poser 4. A trunk-neck-head model was utilized for tracking the skier's trajectory. <br><br>RESULTS: Immediately before head impact, the downward velocity component was estimated to be 8 m/s. After impact, the upwards velocity was 3 m/s, whereas the velocity parallel to the slope surface was reduced from 33 m/s to 22 m/s. The frontal plane angular velocity of the head changed from 80 rad/s left tilt immediately before impact to 20 rad/s right tilt immediately after impact. <br><br>CONCLUSION: A unique combination of HD video footage and accurate measurements of landmarks in the slope made possible a high quality analysis of head impact velocity in a severe TBI case. The estimates can provide crucial information on how to prevent TBI through helmet performance criteria and design.<p /> <p>Language: en</p>",
language="en",
issn="0195-9131",
doi="10.1249/MSS.0000000000000511",
url="http://dx.doi.org/10.1249/MSS.0000000000000511"
}