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ABSTRACT: We have limited insight into how injuries occur in professional ski racing. The aim of this study was to describe the injury situations in World Cup alpine skiing. Injuries reported through the International Ski Federation Injury Surveillance System for three consecutive World Cup seasons (2006-2009) were obtained on video. In total, 69 injuries and 124 runs of matched controls were analysed by five experts to evaluate the skiing situation, skier behavior, as well as piste-related factors. A chi-square test (95% CI, P ≤ 0.05) was used to examine whether there was a difference between course sections regarding where the injury situation occurred. The skier was most frequently turning (n = 55) or landing from a jump (n = 13) at the time of injury. Most of the injuries to the head and upper body (96%) resulted from crashes, while the majority of knee injuries (83%) occurred while the skier was still skiing. Gate contact contributed to 30% of the injuries, while 9% occurred at contact with safety nets/material. Almost half of the injuries (46%) occurred in the final fourth of the course. A particular concern was the high contribution of inappropriate gate contact and the high-energy impacts to the body when crashing.
Scandinavian Journal of Medicine and Science in Sports 01/2013; · 2.87 Impact Factor
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ABSTRACT: Background We have limited insight into the mechanisms of anterior cruciate ligament (ACL) injuries in alpine skiing, particularly among professional ski racers. Objective To describe the mechanisms of ACL injury in World Cup alpine skiing. Design Descriptive video analysis. Setting World Cup alpine skiing. Methods 20 cases of ACL injuries reported through the International Ski Federation Injury Surveillance System for three consecutive World Cup seasons (2006-2009) were obtained on video. Seven international experts performed visual analyses of each case to describe the injury mechanisms in detail (skiing situation, skier behaviour, biomechanical characteristics). Results Three main categories of injury mechanisms were identified: the slip-catch, landing back-weighted and the dynamic snowplow. The slip-catch mechanism accounted for half of the cases (n=10), and all these injuries occurred during turning, without or before falling. The skier lost pressure on the outer ski, and while extending the outer knee to regain grip, the inside edge of the outer ski abruptly caught in the snow, forcing the knee into internal rotation and valgus. The same loading pattern was observed for the dynamic snowplow (n=3). The landing back-weighted category included cases (n=4) where the skier was out of balance backwards in-flight after a jump and landed on the ski tails with nearly extended knees. The suggested loading mechanism was a combination of tibiofemoral compression, boot induced anterior drawer and quadriceps anterior drawer. Conclusion A consistent pattern was observed where the main mechanism of ACL injury in World Cup alpine skiing appeared to be a slip-catch situation where the outer ski suddenly catches the inside edge, abruptly forcing the outer knee into internal rotation and valgus. A similar loading pattern was observed for the dynamic snowplow. Injury prevention efforts should focus on the slip-catch mechanism and the dynamic snowplow.
British journal of sports medicine 04/2011; 45(4):326-7. · 2.55 Impact Factor
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ABSTRACT: Background We have identified that a slip-catch situation is the main mechanism for anterior cruciate ligament (ACL) injuries in World Cup alpine skiing by simple visual inspection of injury videos. This occurs when the skier loses pressure on the outer ski during turning, and while extending the outer knee to regain grip, the inside edge of the outer ski catches abruptly, forcing the knee into valgus and internal rotation. To develop injury prevention methods based on this mechanism, a more precise description is needed. Objective To describe the detailed joint kinematics in a slip-catch situation using a model-based image-matching (MBIM) technique. Design Case study. Setting Men's World Cup alpine skiing. Methods Video of a slip-catch injury situation in slalom captured with two nearly perpendicular camera views was analyzed using the MBIM method to obtain the time course of knee and hip joint kinematics. Results Knee valgus and internal rotation angle increased by 13° and 13°, respectively, in the last 60 ms before the time of ACL rupture, which was estimated to occur 100 ms after the catching the edge. Knee flexion angle increased by 32° in the last 20 ms from 22° at snow contact to a final position. Hip flexion and adduction angle increased by 18° and 13°, respectively, in the last 20 ms and the hip stayed at approximately 30° of internal rotation in the last 60 ms. Conclusion Abrupt compression, valgus and internal rotation loading seems to be the main mechanism of slip-catch injury situations in ACL injuries in World Cup alpine skiing. The knee loading pattern described from the previous simple visual inspection study matched well with the more detailed analysis using the MBIM technique. Prevention efforts should focus on avoiding valgus and internal rotation loading on the knee.
British journal of sports medicine 04/2011; 45(4):327. · 2.55 Impact Factor
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ABSTRACT: Limited knowledge exists on injuries among professional alpine skiers.
To describe the risk of injury and the injury pattern among competitive World Cup alpine skiers during the competitive season.
Retrospective interviews were performed with all World Cup athletes from 10 nations at the end of the 2006-7 and 2007-8 winter seasons, and all acute injuries occurring during the 4.5-month competitive season were recorded. If the athlete was not present, their coaches or medical personnel were interviewed.
A total of 191 acute injuries were recorded among 521 World Cup alpine skiers. As many as 86 injuries (45%) occurred during World Cup/World Ski Championship competitions, corresponding to an injury rate of 9.8 injuries per 1000 runs (95% CI 7.8 to 11.9). The injury rate was found to increase with increasing speed (slalom 4.9 injuries per 1000 runs, 95% CI 2.5 to 7.4--giant slalom 9.2, 5.1 to 13.3--super-G 11.0, 5.2 to 16.8--downhill 17.2, 11.6 to 22.7). The most frequently injured body part was the knee, with 68 injuries (36%), and 37 of these were severe. The overall injury rate was higher in males than in females, but not for knee injuries.
The risk of injury among World Cup athletes in alpine skiing is even higher than previously reported. The knee is the most commonly injured body part and with many severe injuries. Injury rate increased with a higher speed and was higher among males than in females.
British journal of sports medicine 12/2009; 43(13):973-8. · 2.55 Impact Factor
