Impact of environmental factors on knee injuries in male and female recreational skiers

In alpine skiing, the knee represents the dominant injury location with marked gender differences. Snow, slope and weather conditions as well as altitude and low temperatures are thought to influence the prevalence of knee injuries. Therefore, ski patrol injury reports were used to compare gender-specific prevalence of knee injuries with regard to several environmental factors including the actual air temperatures. A total of 1039 non-contact knee injuries were reported with a corresponding prevalence of knee injuries of 44.4% (males: 30.1%; females: 57.4%). Temperature quartiles of all recorded injuries were calculated to compare gender-specific prevalence of knee injury with regard to temperatures. Comparing the first quartile (mean temperature -11°C) with the fourth quartile (mean temperature +3°C), the prevalence of knee injury in female skiers was higher at low ambient temperatures (61% vs 50%, odds ratio: 1.60, 95% confidence interval: 1.16-2.22; P=0.005) while no such association was found for male skiers. Additionally, knee-injured females showed a twofold prevalence when skiing during snowfall compared with females with other injuries (15.4% vs 8.6%; P=0.001). No other environmental factor showed a significant association with the gender-specific prevalence of knee injury. In conclusion, low ambient temperature and snowfall are important environmental risk factors for knee injuries in female skiers.     

Occurrence and trends in ski injuries in Norway

OBJECTIVES: To provide an overview of ski injuries in Norway and to describe the changes between 1990 and 1996. METHODS: All ski injuries (7966) treated at four hospitals providing health care to a defined population of about 11% of the Norwegian population were registered prospectively from 1990 to 1996. For this study, 6462 injuries sustained in cross country skiing, downhill skiing, telemark skiing, and snowboarding were selected for further analysis. RESULTS: The relative distribution of ski injuries by type of skiing changed significantly from 1990 to 1996 (p<0.001). Injuries from snowboarding showed the highest relative increase, and those sustained during downhill skiing showed a decline. The proportion of fractures in all types of skiing increased during the study period (p=0.001). The proportion of injuries to knee/lower leg decreased and the proportion to the forearm/wrist/hand increased during the study period (p=0.03). The mean age of the injured skiers differed significantly among the different types of skiing activity (p<0.001): cross country skiers were the oldest followed by telemark skiers, downhill skiers, and snowboarders. CONCLUSIONS: Ski injury surveillance results in early detection of changes in temporal injury trends, allowing timely adjustment of injury prevention strategies. Injuries from snowboarding are on the increase in Norway, warranting more effective injury prevention measures.


     

Effect of functional bracing on knee injury in skiers with anterior cruciate ligament reconstruction: a prospective cohort study

BACKGROUND: The role of knee bracing in anterior cruciate ligament reconstructions is controversial. HYPOTHESIS: Functional bracing will have an effect on subsequent knee injury in skiers with anterior cruciate ligament reconstruction. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: From 1991 to 1997, 11606 skiers at a major destination ski resort underwent preseason knee screening. The anterior cruciate ligament-reconstructed group consisted of 820 skiers who had had an anterior cruciate ligament reconstruction 2 years or more earlier. Of these, 257 skiers selected the use of functional knee brace during skiing. The dependent variable was subsequent knee injury, identified via workers' compensation records. Covariates included age, gender, ski occupation, Lachman grade, pivot-shift grade, KT-1000 arthrometer manual maximum displacement, and use of a functional brace. Univariate and multivariate risk factors for subsequent knee injury were determined. RESULTS: In this study, 257 skier-employees with anterior cruciate ligament reconstruction wore braces and 563 skier-employees with anterior cruciate ligament reconstruction did not. Braced skiers had significantly higher preseason rates of grade II or higher Lachman and pivot-shift tests (braced, 29% and 22%, respectively; nonbraced, 11% and 10%, respectively; P < .05). Sixty-one subsequent knee injuries were identified, 51 (8.9 injuries/100 knees/ski season) in the nonbraced group and 10 (4.0 injuries/100 knees/ski season) in the braced group (P = .009). Nonbraced skiers were 2.74 times more likely to suffer subsequent injury than were braced skiers (odds ratio, 2.74 [confidence interval, 1.2-4.9]). Logistic regression modeling identified nonbracing as a significant independent multivariate risk factor for subsequent knee injury in the high-demand skiers with anterior cruciate ligament reconstruction. CONCLUSION: Because of the increased risk of subsequent knee injury in nonbraced skiers, the authors recommend functional bracing for skiers with anterior cruciate ligament reconstruction. Whether the protective effect of functional bracing can be extrapolated to other high-demand patients is yet to be determined.     

Recording injuries only during winter competitive season underestimates injury incidence in elite alpine skiers

Current epidemiological studies in elite alpine skiers are mostly limited to retrospective surveys on in-season injury. The aim of this study was to determine the risk and pattern of injury in elite alpine skiers during the winter competitive season (WCS) and the summer off-season (SOS). European Cup skiers were prospectively followed during 5 complete years. A total of 133 skier-seasons (79 males and 54 females) completed the study. All acute and overuse injuries that required medical attention were registered, representing a total of 166 injuries. Absolute injury incidence was 124.8 (95% CI [106-145]) injuries per 100 athletes per complete season and was higher during the WCS compared with the SOS, albeit in a smaller magnitude than expected (relative risk ratio (RR) 1.44 [1.06-1.96]). The absolute incidence of severe injuries (ie, time-loss >28 days) was twofold higher during WCS compared with SOS (RR 2.19 [1.21-3.95]). Most common injuries during the 2013-2015 seasons were knee followed by back (absolute incidences 56 [38-80] and 20 [10-36], respectively; RR 2.82 [1.42-5.61]), but this difference disappeared after 2015 (absolute incidences 25.6 [15.7-39.6] and 23.1 [13.7-36.5], respectively; RR 1.11 [0.59-2.10]). In summary, we found that 98 (59%) injuries occurred during WCS and 68 (41%) during SOS over 5 years. These results demonstrate the necessity to record injuries during the entire year to avoid a significant underestimation of the injury incidence. In addition, the current data showed an evolution of injury pattern over time and since previous reports, with back injuries being the main concern along knee joint injuries.     

Risk of injury during alpine and telemark skiing and snowboarding. The equipment-specific distance-correlated injury index

Estimation of injury risk in alpine sports is difficult. We present a new method of calculating an injury index related to the distance traveled on ski or snowboard. The distance-correlated injury index equals the number of injuries per 100,000 km traveled distance. This injury index can also be correlated to the type of equipment used. The equipment-specific distance-correlated injury index is the same as the distance-correlated injury index, but it is sport-specific. We found the distance-correlated injury index for alpine skiing to be 3.9 (95% Cl = 2.8 to 5.4); for snowboarding, 13.5 (95% Cl = 8.3 to 22.0); and for telemark skiing, 3.0 (95% Cl = 1.0 to 9.4), suggesting a three- to four-times higher incidence of injuries requiring hospital treatment among snowboarders than among alpine and telemark skiers.     

Interaction of potential intrinsic and extrinsic risk factors in ACL injured recreational female skiers

The aim of this study was to investigate the interaction of potential intrinsic and extrinsic risk factors in ACL injured recreational female skiers. 93 female recreational skiers who had suffered a non-contact ACL injury and 93 age-matched controls completed a self-reported questionnaire relating to intrinsic risk factors (menstrual history, BMI, previous knee injuries, self reported weekly sports participation) and extrinsic risk factors (type of ski used, time of last binding adjustment, snow condition, weather and slope difficulty). A logistic regression model revealed the following independent ACL injury risk factors for female recreational skiers: icy snow conditions (odds ratio, 24.33; 95% confidence interval, 6.8-86.5, P<0.001), skiing during snowfall (odds ratio, 16.63; 95% confidence interval, 1.8-152.1, P=0.013), use of traditional skis (odds ratio, 10.49; 95% confidence interval, 2.0-54.5, P=0.005), and preovulatory phase of menstrual cycle (odds ratio, 2.59; 95% confidence interval, 1.2-5.5, P=0.013). In conclusion, ACL injuries in female recreational skiers are the result of a complex interaction of intrinsic and extrinsic risk factors.     

Self-reported skill level and injury severity in skiers and snowboarders

There is evidence to suggest that the rate of injury is lower for expert skiers and snowboarders than for beginners. A better understanding of the relation between injury severity and skill level is also needed for planning injury prevention strategies. Our objective was to examine the severity and location of injuries sustained by self-reported expert and beginner skiers and snowboarders. A case-control study design was used. Injured skiers and snowboarders had to report their skill level on a 5 point scale (1: “beginner”; 5: “expert”). Two sets of severely injured cases were defined based on the type of injury and ambulance evacuation. Controls were those who did not sustain severe injuries. Logistic regression analyses were performed to relate injury severity to skill level. Subjects were 22 078 injured skiers and snowboarders who reported to the ski patrol with an injury sustained on the slopes of an alpine ski centre of the Canadian province of Québec during the seasons 2001–2002 to 2004–2005. Compared with beginners, experts had an increased risk of suffering from a severe injury (adjusted odds ratio [AOR]: 1.88; 95% CI: 1.58–2.23). Expert snowboarders were also more likely to suffer from a severe injury or be evacuated by ambulance (AOR: 1.18; 95% CI: 1.02–1.38). Results suggest that the type of activities or manoeuvres performed by expert skiers and snowboarders may increase the risk of sustaining a severe injury compared with beginner participants.     

Epidemiology of alpine skiing injuries in lowlanders

During one alpine skiing season injuries were registered prospectively among 951 Danish alpine skiers. The injury incidence was 19.4 injuries per 1000 skiing days, or 3.4 injuries per 1000 skiing hours. The incidence of injuries treated by a doctor was 5.9 injuries per 1000 skiing days, which is 2–5 times higher than previously reported. Lower extremity doctor-treated injuries comprised 65% of the total and upper extremity doctor-treated injuries 25% - a distribution seen 25 years ago in alpine skiing countries. Only 18% of the thumb injuries were seen by a doctor. Neither age, preholiday training, self-rated skiing ability, ski school attendance during the week nor the use of rented versus owned equipment significantly influenced the risk of injury.     

Snow sports injuries in Scotland: a case-control study

OBJECTIVES: To examine the incidence and patterns of snow sports injuries at the three largest commercial ski areas in Scotland and to identify factors associated with injury risk. METHODS: A prospective case-control study of all injured people at Cairngorm, Glenshee, and Nevis Range ski areas during the 1999-2000 winter season. Personal details, snow sports related variables, diagnosis, and treatment were recorded. Control data were collected at random from uninjured people at all three areas. Random counts were performed to analyse the composition of the on slope population. RESULTS: A total of 732 injuries were recorded in 674 people. Control data were collected from 336 people. The injury rate for the study was 3.7 injuries per 1000 skier days. Alpine skiers comprised 67% of the on slope population, snowboarders 26%, skiboarders 4%, and telemark skiers 2%. Lower limb injuries and sprains were the commonest injuries in alpine skiers and skiboarders. Snowboarders sustained more injuries to the upper limb and axial areas. Skiboarders and snowboarders had a higher incidence of fractures. After adjustment for other variables, three factors were all independently associated with injury: snowboarding (odds ratio (OR) 4.07, 95% confidence interval (CI) 1.65 to 10.08), alpine skiing (OR 3.82, CI 1.6 to 9.13), and age <16 years (OR 1.9, CI 1.14 to 3.17). More than five days of experience in the current season and at least one week of experience in total had a protective effect against injury. CONCLUSIONS: Despite a change in the composition of the alpine population at Scottish ski areas, the overall rate and pattern of injury are similar to those reported previously in comparable studies. Several factors are associated with an increased risk of injury and should be targeted in future injury prevention campaigns.     

Snow skiing injuries in physically disabled skiers.

This study, through retrospective review, examines the injury rate of selected disable skiing populations in general and as compared to able-bodied skiers in areas where comparison was possible. Data on disabled skiers gathered from instructional programs at multiple sites indicate that the disabled skier had a very low rate of injury occurrence. Where comparison could be make, it was found that there was no significant difference in overall injury rates between able-bodied and physically disabled skiers. Disabled skiers appear to sustain less severe injuries, and they do not show the trend in increasing injury rates that able-bodied skiers in this study show. In addition, the uphill transport of skiers with a disability who use sit- or mono-skis was examined in one large program and found to be efficient and exceedingly safe, with no injuries reported. A major limitation of this study is the inconsistency in methods of data collection and reporting. There is a need for further prospective studies in the general able-bodied and disabled skiing populations with direct comparisons of rate, location and severity of injury, type of disability, and experience level of the skier. We hope that this study will stimulate more ski areas to allow disabled skiers on their slopes, even it limited to participation in supervised, instructional programs.     

Reduction of injuries in downhill skiing by use of an instructional ski-video: a prospective randomised intervention study

Despite various attempts at prevention, injury in downhill skiing continues to be a worrisome recreational problem. The purpose of this study was to test the effect of an instructional ski video on the behaviour and injuries of 763 downhill skiers. They were enrolled in two study groups, based on whether or not an instructional video had been shown in their bus on the way to a skiing resort. The video focussed on information regarding how to get started in downhill skiing and injury prevention. The outcome parameters, behaviour (binding test and adjustment), injury risk, type and consequence, were registered on the return trip 8 days later by a questionnaire. In the intervention group all outcome parameters changed significantly. The binding test was performed by 86% in the intervention group and by only 59% in the control group (P < 0.05). Adjustment of the bindings was done by 22% in the intervention group vs 14% in the control group. Regarding injury risk, 205 injuries were seen in 158 persons (20.7%) which is 26 injured skiers per 1000 skier-days and 33.6 injuries per 1000 skier-days. In the intervention group 16% of all skiers were injured vs 23% in the control group, yielding a reduction in injury risk of 30% (P < 0.05). Injuries caused by falls were seen in 12.6% in the intervention group vs 16.2% in the control group (P < 0.05). Injuries caused by collision were seen in 6% of the intervention group vs 12% in the control group (P < 0.05). The overall mean injury risk was 16 injuries per 1000 falls. Knee injuries made up 32.6% of the total. For inexperienced skiers the knee injury risk was significantly lower if the bindings had been tested (P < 0.05). Therefore, an instructional ski video can change the behaviour of downhill skiers and reduce the injury risk and consequences significantly. Received: 26 March 1997 Accepted: 20 December 1997     

MRI of snow skiing and snowboarding injuries

Snow skiing has been called "the world's oldest sport," "the fastest non-motorized sport on Earth," and "the riskiest sport undertaken by adults on a routine basis." This article discusses the common mechanisms for orthopedic injuries occurring in two of the most popular winter sports in the world that have a reputation for an inherently high risk of injury: alpine skiing and snowboarding. The emphasis herein is on magnetic resonance imaging of characteristic injuries in skiers (knee, thumb, shoulder) and in snowboarders (wrist, forearm, ankle). Spine injuries in snowboarders and skiers are also discussed.     

INDEX to volume 13 jan-dec 1985

In brief: Although data are difficult to interpret because injury reporting is often sketchy, in the past 15 years the overall injury rate for skiers seems to have decreased by about 50%. One of the most important factors in this decline has been the development of improved equipment. Whereas formerly the principal severe skiing injury was the tibial fracture, now knee ligament injuries are dominant, probably because the newer boots block ankle rotation and transfer forces to the knee. Equipment plays such a major role in injury protection that skiers should choose it carefully with the help of knowledgeable ski shop personnel. In this discussion, participants examine how safe skiing is, pointing out that skiing safety is a function of the rate and severity of the injuries, both of which are difficult to define and measure. Other topics discussed include types of equipment needed to prevent injury and trends in equipment design.     

Blood profiles in elite cross-country skiers: a 6-year follow-up

Following the doping scandals at the World Championships in cross-country skiing in 2001, the International Ski Federation decided to generate individual blood profiles. From 2001 to 2007, 7081 blood samples from 1074 male and female elite cross-country skiers were collected and analyzed for hemoglobin concentration [Hb] and % reticulocytes (%rets). Data were applied to blood algorithms wherefrom blood model scores were calculated. From 1997–1999 to 2001–2002, the mean [Hb] was reduced by 0.9 g/dL to 15.3 g/dL in male skiers and by 0.4 g/dL to 13.8 in female skiers. From 2002–2003 to 2006–2007, the combination of increases in [Hb] and decreases in %rets led to pronounced increases in mean OFF-model scores. [Hb] was 0.2 g/dL higher at Olympic Games/World Championships (WOCs) than at World Cups competitions <4 weeks before and after WOCs. [Hb] and %rets increased with altitude in both genders. Since the introduction of an enlarged blood testing program, the mean [Hb] values were lowered to close to normal levels, but over the last 2–3 years there has been a small elevation and an increase in OFF-model scores, which may indicate a change in the manipulations used to elevate the [Hb].     

Self-estimation of ability among skiers and snowboarders in alpine skiing resorts

Skiing ability is thought to be an important risk factor for injuries, but the best method to classify skiing ability is not known. The objective of this study was to validate five different questions designed to self-report skiing ability for ski injury surveillance. To this end 512 alpine skiers, Telemark skiers, snowboarders and skiboarders were asked to selfestimate their skiing ability using five different questions based on skiing skill, piste difficulty, turning technique, skiing experience and falling frequency, each with four categories. The participants then made a test run to test their skiing ability. Observed and self-reported skiing ability were compared using kappa statistics. The correlation between observed and self-reported skiing ability was low to fair, with kappa values of 0.34 for skiing skill), 0.33 for piste difficulty, 0.38 for turning technique, 0.26 for experience and 0.16 for falling frequency. However, the sensitivity and specificity for each of the questionnaires in discriminating between individuals in the poorest skiing ability category on the test and the rest of the group was relatively good (skiing skill: sensitivity 75%, specificity 91%; piste difficulty 68, 96%; turning technique 75, 91%; experience 75, 90%; falling frequency 61, 97%). The results show that the capacity to self-assess skiing ability is limited, but estimation based upon turning technique or skiing skill seem to be best methods for epidemiological studies on injuries in snow sports.     

Head injuries in snowboarders compared with head injuries in skiers. A prospective analysis of 1076 patients from 1994 to 1999 in Niigata, Japan

We investigated snowboarding-related head injury cases and skiing-related head injury cases during five ski seasons at one resort area. There were 634 snowboarding-related head injuries and 442 skiing-related head injuries. The number of snowboarding head injuries increased rapidly over the study period. More male snowboarders than female snowboarders suffered head injuries. For both snowboarders and skiers, head injuries frequently occurred on the easy and middle slopes. Falls were the most frequent causes of injury in both groups. Jumping was a more frequent cause of injury in the snowboarders (30%) than in the skiers (2.5%). Injury to the occipital region predominated in the snowboarders as compared with the skiers. There were 49 organic lesions in 37 snowboarders and 46 organic lesions in 33 skiers. Subdural hematoma was frequent in the snowboarding head injury group, and fracture was frequent in the skiing head injury group compared with the snowboarding group (not significant). Subdural hematoma was likely to be caused by a fall rather than by a collision, and bone fracture was likely to be caused by a collision rather than by a fall. Four snowboarders and one skier died as a result of their head injuries. Our data suggest that snowboarding head injuries may be prevented by protection of the occipital region and refraining from jumping by beginners.     

The association between removing and reintroducing man-made jumps in terrain parks and severe alpine skiing and snowboarding injuries

ObjectivesTo explore the effect of removing and reintroducing man-made jumps in terrain parks (TPs), on the proportion of severe injuries among alpine skiers and snowboarders in Québec, Canada.DesignQuasi-experimental study.MethodsInjuries were identified via injury report forms completed by ski patrollers during seasons 2000–2001 to 2016–2017 in Québec ski areas. Severe injuries were defined based on the type of injury or ambulance evacuation. Logistic regression analysis was used to provide adjusted odds ratios (AOR) for the comparison of the time periods before jump removal (PRE) and after jump reintroduction (POST) with the jump removal interval (INT).ResultsCompared with INT, the proportion of severe injuries in PRE was not significantly different (AOR: 1.05; 95% CI: 0.85–1.30), but was higher in POST (AOR: 1.76; 95% CI: 1.24–2.51) for ski areas with jump removal. In ski areas without jump removal, there was no change in PRE (AOR: 0.96; 95% CI: 0.87–1.07) and increased odds of severe injuries in POST (AOR: 1.20; 95% CI: 1.07–1.35). A supplementary analysis suggested that removing jumps from TPs has contributed significantly to a reduction in the proportion of severe injuries. This protective effect appears to decline over time.ConclusionsThese results do not suggest that removing jumps from TPs as an effective long-term injury prevention strategy in skiing and snowboarding. Collecting data on exposure could improve our understanding of how removing, introducing or reintroducing man-made jumps in TPs is associated with the risk of minor and severe injuries in TPs and on regular trails.