Acute on-snow severe injury events in elite alpine ski racing from 1997 to 2019: the Injury Surveillance System of the Austrian Ski Federation.

OBJECTIVES: The study aimed to (1) determine the incidence and gender-specific risk ratio of acute on-snow severe injury events (SIE) in elite alpine ski racing, (2) examine the development of SIE over 22 seasons, and (3) analyse SIE with respect to the severely injured body parts and structures. METHODS: Data recorded in the Austrian Ski Federation's Injury Surveillance System over 22 seasons were analysed. The Austrian Ski Team consists of four groups: Team National (n=477), Team A (n=444), Team B (n=696) and Team C (n=608). Team National and Team A comprised World Cup, Team B European Cup and Team C junior alpine ski racers. Simple and multiple Poisson regressions were calculated. RESULTS: The SIE incidence was 15.7 (95% CI 14.2 to 17.5) per 100 skier seasons. ACL injury events accounted for 70.8% of severe knee injury events and 48.6% of SIE. The incidence of severe ACL injury events was 7.6 (95% CI 6.6 to 8.9). Female World Cup alpine ski racers had a 1.65 times (95% CI 1.02 to 2.69) higher risk of severe ACL injury events than their male counterparts. CONCLUSION: The incidence of acute on-snow SIE in World Cup alpine ski racing was higher than previously reported. Despite various prevention efforts, the average seasonal incidence of SIE in World and European Cup alpine ski racers has grown from approximately 11 in 1997 to 23 in 2019; thus with roughly one more injured athlete every second season.

The 2 Minute Loaded Repeated Jump Test: Longitudinal Anaerobic Testing in Elite Alpine Ski Racers.

This study investigated the 4-year development of anaerobic power and capacity in Austrian elite female alpine ski racers and examined the relationship between the 2-minute loaded repeated jump test (LRJT) results and ski racing performance (International Ski Federation (FIS) points). Ten Austrian elite female ski racers were tested prior to four racing seasons. The LRJT consisted of 48 loaded countermovement jumps (LCMJs) with barbell load equivalent to 20% bodyweight. Before the LRJT, maximal body mass normalized average power of a single LCMJ (PMAX) was determined. The mean jump power was calculated across all jumps in the test (P0-120). Anaerobic power (PMAX) in season 2 (32.3 ± 2.3 W·kg-1) significantly improved over season 1 (30.5 ± 2.3 W·kg-1) (p < 0.05) but there were no further differences between seasons, with season 3 at 33.5 ± 3.4 W·kg-1 and season 4 at 33.6 ± 3.0 W·kg-1. Anaerobic capacity (P0-120) increased up to season 3 by 9.2% (27.1 ± 2.8 to 29.6 ± 2.4 W·kg-1), but was significantly higher only when comparing season 4 to seasons 1 and 2 (p < 0.05). FIS points changed significantly (p < 0.05), from 18.1 ± 8.2 in season 1 to 8.4 ± 4.8 in season 4 (lower FIS points indicates better racing results). FIS points had a positive relationship with PMAX (r = -0.73, p < 0.05) and P0-120 (r = -0.64, p < 0.05) only in season 4. Improvements in FIS points from year to year did not correlate with seasonal increases in LRJT results. In conclusion, anaerobic power improved only after season 1, and anaerobic capacity changes were evident only in season 4. Ski racing performance (FIS points) correlated with LRJT test results in only season 4. The LRJT can monitor a ski racer's anaerobic power and capacity, but does not correlate with ski racing performance.

The 2.5-minute loaded repeated jump test: evaluating anaerobic capacity in alpine ski racers with loaded countermovement jumps.

The purposes of this study were to test the reproducibility of the 2.5-minute loaded repeated jump test (LRJT) and to test the effectiveness of general preparation period (GPP) training on anaerobic fitness of elite alpine ski racers with the LRJT. Thirteen male volunteers completed 2 LRJTs to examine reliability. Nine male Austrian elite junior racers were tested in June and October 2009. The LRJT consisted of 60 loaded countermovement jumps (LCMJs) with a loaded barbell equivalent to 40% bodyweight. Before the LRJT, the power (P) of a single LCMJ was determined. Power was calculated from ground reaction forces. The mean P was calculated for the complete test and for each 30-second interval. The interclass correlation coefficients (between 0.88 and 0.99) for main variables of the LRJT demonstrated a high reliability. A repeated-measures analysis of variance indicated that anaerobic capacity was significantly higher in October (p ≤ 0.05). The ski racers' single LCMJ P increased from 37.0 ± 1.2 W·kg to 39.0 ± 1.4 W·kg. The mean P of the total test improved from 33.6 ± 1.2 W·kg to 35.8 ± 1.3 W·kg, but relative effect of fatigue did not change. The GPP training improved the athletes' ability to produce and maintain muscular power. The LRJT is a reliable anaerobic test suitable for all alpine ski racing events because the 60 jumps simulate the approximate number of gates in slalom and giant slalom races and the 2.5 minutes is equivalent to the duration of the longest downhill race.

Physical characteristics of experienced and junior open-wheel car drivers.

Despite the popularity of open-wheel car racing, scientific literature about the physical characteristics of competitive race car drivers is scarce. The purpose of this study was to compare selected fitness parameters of experienced and junior open-wheel race car drivers. The experienced drivers consisted of five Formula One, two GP2 and two Formula 3 drivers, and the nine junior drivers drove in the Formula Master, Koenig, BMW and Renault series. The following fitness parameters were tested: multiple reactions, multiple anticipation, postural stability, isometric upper body strength, isometric leg extension strength, isometric grip strength, cyclic foot speed and jump height. The group differences were calculated using the Mann-Whitney U-test. Because of the multiple testing strategy used, the statistical significance was Bonferroni corrected and set at P < 0.004. Significant differences between the experienced and junior drivers were found only for the jump height parameter (P = 0.002). The experienced drivers tended to perform better in leg strength (P = 0.009), cyclic foot speed (P = 0.024) and grip strength (P = 0.058). None of the other variables differed between the groups. The results suggested that the experienced drivers were significantly more powerful than the junior drivers: they tended to be quicker and stronger (18% to 25%) but without statistical significance. The experienced drivers demonstrated excellent strength and power compared with other high-performance athletes.

The relationship between ACL injuries and physical fitness in young competitive ski racers: a 10-year longitudinal study.

BACKGROUND: Epidemiological studies have shown a high incidence of anterior cruciate ligament (ACL) injuries among competitive alpine skiers. Little is known regarding modifiable risk factors in young skiers. There are still uncertainties in gender-related risk factors. OBJECTIVE: The purpose of this study was to determine the relationship between ACL injuries and internal risk factors. METHODS: Retrospective data analyses were performed based on a group of 175 female and 195 male alpine ski racers between the ages of 14 and 19 years. The athletes underwent physical testing annually from 1996 to 2006. Z score transformations normalised the age groups. Multivariate binary logistic regressions were calculated for men and women separately to detect significant predictors of ACL ruptures. t Tests were computed to reveal the differences in test scores between injured and non-injured athletes. RESULTS: A total of 57 (15%) ACL injuries occurred. The female-male risk ratio (RR) was higher in females (2.3, 95% CI 1.3 to 4.2). Z scores for relative leg force, ratio of absolute core flexion to extension force, relative core strength and reactive strength index were predictive variables for men. Z scores of all of these predictive variables except relative leg force were higher in the non-injured group. The ratios of absolute flexion to extension force and absolute core strength were predictive covariates for women. Z scores for absolute core strength were higher in the non-injured group. CONCLUSIONS: The risk of ACL injury was greater in female athletes. The findings suggest that core strength is a predominant critical factor for ACL injuries in young ski racers.

The effect of gender on force, muscle activity, and frontal plane knee alignment during maximum eccentric leg-press exercise.

PURPOSE: To investigate for gender differences during eccentric leg-press exercise. Tears of the anterior cruciate ligament (ACL) are considered to be related to eccentric tasks, altered neuromuscular control (e.g., reduced co-contraction of hamstrings), and increased knee abduction (valgus alignment). Based on these observations and the fact that ACL tears are more common in women, it was hypothesized that men and women differ significantly with regard to key parameters of force, knee stabilization, and muscle activity when exposed to maximum eccentric leg extension. METHODS: Thirteen women and thirteen men were matched for age and physical activity. They performed maximum isokinetic eccentric leg-pressing against footplates of varied stability. The latter was done because earlier studies had shown that perturbational test conditions might be relevant in respect of ACL injuries. Key parameters of force, frontal plane knee stabilization, and muscle recruitment of significant muscles crossing the knee were recorded. RESULTS: The 'force stabilization deficit' (difference between maximum forces under normal and perturbed leg-pressing) did not differ significantly between genders. Likewise, parameters of muscle activity and frontal plane leg stabilization revealed no significant differences between men and women. CONCLUSION: This study is novel, in that gender differences in parameters of force, muscle activity, and leg kinematic were investigated during functional conditions of eccentric leg-pressing. No gender differences were observed in the measured parameters. However, the conclusion should be viewed with caution because the findings concurred with, but also contrasted, previous research in this field. LEVEL OF EVIDENCE: Diagnostic study, Level III.

In-Competition Severe Injury Events in Elite Alpine Ski Racing from 1997 to 2020: The Case of the Austrian Ski Team.

BACKGROUND: To increase safety in elite alpine ski racing Injury Surveillance Systems were implemented and preventive measures introduced. However, studies analysing the change in athletes' injury risk by controlling for their exposure are still scarce. OBJECTIVES: This study aimed to describe and analyse the risk of in-competition severe injury events (SIEcomp) in elite alpine ski racing. METHODS: Data recorded in the Austrian Ski Federation's Injury Surveillance System were used to analyse the SIEcomp incidence. Information on athletes' competition exposure was obtained from the official website of the International Ski Federation. In 23 seasons, 2333 skier seasons were recorded for the Austrian Ski Team. Within a total of 114,531 runs 169 SIEcomp occurred. Generalised Estimating Equation for Poisson Regressions were applied. RESULTS: The SIEcomp incidence per 1000 runs was 1.48 [95% confidence interval (CI) 1.26-1.73] for elite alpine ski racers and 2.21 (95% CI 1.79-2.75) for the subgroup of World Cup racers. A significant sex difference was detected for the subgroup of junior racers with a higher risk for female athletes [risk ratio (RR): 2.97, 95% CI 1.46-6.05]. Between the seasons of 1997 and 2020, the seasonal SIEcomp incidence increased by a factor of 2.67 for elite alpine ski racers and 3.53 for World Cup racers. Downhill (2.75, 95% CI 2.18-3.47) had the highest SIEcomp incidence, followed by super-G (1.94, 95% CI 1.30-2.88), giant slalom (1.40, 95% CI 1.06-1.85), and slalom (0.64, 95% CI 0.43-0.96). CONCLUSION: Although many preventive measures have been implemented in elite alpine ski racing, the risk of SIEcomp has increased over the last two decades.

Did injury incidence in alpine ski racing change after equipment regulations? An evaluation based on the injury surveillance system of the Austrian Ski Federation.

OBJECTIVES: To assess the effects of alpine competition equipment regulations from 2003, 2007 and 2012 on severe injury incidence. DESIGN: Case study METHOD: Data originated from records of the injury surveillance system of the Austrian Ski Federation. Injuries from the seasons 2001-2017 were divided in four periods between the equipment regulations. For comparison of consecutive periods, risk ratios (RR = later period / preceding period) with 95% CI were calculated. Total severe injury events, events with severe knee injuries, and events with severe ACL injuries were separately investigated. RESULTS: A significant increase of total severe injury incidence was found after the equipment regulation in 2003 (RR1.52, 95% CI 1.00-2.31). None of the other comparisons revealed significance (p<0.05) or statistical trends (p<0.1). Only the minority (40%) of the RR showed a reduction in the injury incidence of the Austrian Ski Team (lowest RR 0.78). 60% of the RR increased after the regulations (highest RR 1.63). CONCLUSIONS: Even though statistical uncertainties remain, our findings allow the conclusion, that the implemented equipment regulations did not cause a noticeable reduction of injuries. The three analysed equipment regulations were not appropriate or were counteracted by other factors.

Power variables and bilateral force differences during unloaded and loaded squat jumps in high performance alpine ski racers.

The purpose of this paper was to investigate the power-load relationship and to compare power variables and bilateral force imbalances between sexes with squat jumps. Twenty men and 17 women, all members of the Austrian alpine ski team (junior and European Cup), performed unloaded and loaded (barbell loads equal to 25, 50, 75, and 100% body weight [BW]) squat jumps with free weights using a specially designed spotting system. Ground reaction force records from 2 force platforms were used to calculate relative average power (P), relative average power in the first 100 ms of the jump (P01), relative average power in the first 200 ms of the jump (P02), jump height, percentage of best jump height (%Jump), and maximal force difference between dominant and nondominant leg (Fmaxdiff). The men displayed significantly higher values at all loads for P and jump height (p < 0.05). No significant differences were found in P01. The men had significantly higher P02 at all loads except 75% BW). Maximum P was reached at light loads (men at 25% BW and women at 0% BW), and P decreased uniformly thereafter. Individual power-load curves show a deflection point. It is proposed that the load where the power-load deflection point occurs be used as the power training load and not the load at which maximum P is reached. It is also proposed that loads not be described in %1-repetition maximum (RM), but as %BW. This system can be used to safely assess and train power with loaded jumps and free weights.

Comparison of physical characteristics and performance among elite snowboarders.

There are little scientific data regarding snowboarding and the physiological demands on snowboarders. The aim of this study was to assemble and evaluate a battery of tests for the snowboard disciplines parallel, snowboard cross (SBX), big air, and half-pipe (HP). Thirty-seven competitive snowboarders participated in the study and completed a test battery that comprised tests for aerobic capacity, balance, jumping, isokinetic core power, isokinetic leg power, isometric bench press, isometric bench pull, and a snowboard start simulator. The results showed that the battery of tests explained between 61 and 98% of variance when predicting snowboard performance. The test battery predicts better for women than for men and better for SBX, HP, and overall World Cup ranking than for the other disciplines. The results indicate that starting speed, leg power, core power, and aerobic capacity are important in different snowboarding events.

Safety recommendations of winter terrain park jumps into airbags.

OBJECTIVES: In winter terrain parks special airbags are used for skiers and snowboarders to practice jumps and achieve safe landings. However, in 2010 two skiers landed at the end of oval airbags. One suffered fatal, the other severe, injuries. The aim of this study was to identify parameters that lead to jumping over the airbag and to suggest preventive measures. DESIGN: Simulation study. METHODS: For the calculation of the flight distance the equation of motion was solved for the jumper's approach and flight phase. Measured data of five jumps into an airbag employed in a similar geometry and conditions as in the second accident case were used to validate the simulation and to measure typical takeoff velocities. The effect of approach and takeoff parameters on the flight distance for oval and flat airbags was analyzed with the simulations. RESULTS: In both accident cases a too long approach led to a too high takeoff speed, which was the cause for landing at the end of the oval airbags. The effect of flight distance is considerably more sensitive to approach and takeoff parameters with oval versus flat airbags. CONCLUSIONS: Three measures are recommended to prevent jumping over an airbag. An approach corridor with top and lateral fences has to be set up and the approach should be steep. Flat airbags are preferable to oval airbags. Airbags should be equipped with a heightening at the end.

Performance-determining physiological factors in the luge start.

In luge, the start is a performance-determining factor. Athletes spend several months in the off-season training to improve starting performance. The aim of this study was to evaluate the influence of different physiological factors on the luge start and identify an appropriate physiological test battery. Thirteen male members of the Austrian national luge team were recruited. All participants completed a test battery that consisted of tests for balance, jumping, isometric truck flexion and extension strength, leg strength, hand grip strength, isometric bench pull and bench press strength, flexibility, and a luge start simulator. Regression analyses of fitness variables and starting speeds revealed relationships (P at least 0.049) except for flexibility, isometric trunk flexion strength, and isometric leg strength at a knee angle of 100 degrees (P at best 0.069). Results showed that a single variable (isometric bench pull strength) explained most of the variance in maximum push-off speed (R2 = 0.750) and suggest that any test battery should include bench pull, trunk extension, and grip strength tests. Bench pull performance might also be a useful tool in the recruitment of athletes.