Anterior cruciate ligament injury incidence among male and female professional alpine skiers

A retrospective review of anterior cruciate ligament injuries among professional alpine skiers was performed to compare sex-related differences in injury incidence. We screened 7155 ski patrollers or instructors (4537 men and 2618 women) for knee injuries before each ski season between 1991 and 1997. Screening involved a ski history questionnaire, a knee injury history questionnaire, and a knee physical examination. Any patient with an equivocal Lachman or pivot shift test was evaluated by KT-1000 arthrometry and excluded from the study if the manual maximum side-to-side difference was 3 mm or more. Thus, the study population was limited to subjects with intact anterior cruciate ligaments. Skiers injured during the study were identified through mandatory workers' compensation claims. Each injured skier was reevaluated using an injury questionnaire and physical examination. The men skied an average of 110 days per year (499,070 skier-days) and the women skied an average of 87 days per year (227,766 skier-days). Thirty-one skiing-related anterior cruciate ligament injuries were diagnosed, 21 in men and 10 in women. The incidence of ACL disruption was 4.2 injuries per 100,000 skier-days in men and 4.4 injuries per 100,000 skier-days in women. These data suggest that the incidences of anterior cruciate ligament injuries among male and female professional alpine skiers are similar.     

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.     

Injury profile of competitive alpine skiers: a five-year cohort study

Purpose

The aim of this study was to make a survey of injuries in young elite alpine skiers.

Methods

During 5 years, all students at the Swedish Ski High schools were prospectively followed regarding injuries, time of exposure, injury location, type of injury, injury severity and gender. Four hundred and thirty-one skiers, 215 males and 216 females completed the entire study.

Results

Of 431 skiers, 193 (91 males, 102 females) sustained 312 injuries during the 5-year study period. The injury incidence for males was 1.62 injuries/1,000 ski hours or 2.97 injuries/100 months at a Ski High school, and the corresponding values for females were 1.77 and 3.25, respectively. Forty-one percent of the injuries involved the knee, 69% were ligament injuries, and 49% were classified as severe injuries. Of 190 injured skiers, 120 injured their left leg (P = 0.0097). This was their first time injury. The risk of sustaining a re-injury or a new injury increased the sooner the first time injury occurred (P = 0.001).

Conclusion

There was a high risk for alpine ski students to sustain an injury during their education at the Swedish Ski High schools. Most injuries, especially ligament injuries, occurred in the knee joint in both males and females. Both genders were more likely to sustain injuries to the left than to the right leg. Nearly 50% of the injuries were classified as severe.

Level of evidence

II.     

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.     

Dynamic knee valgus in competitive alpine skiers: Observation from youth to elite and influence of biological maturation

Numerous studies investigated the association between dynamic knee valgus and injury risk in post-pubertal and elite athletes; however, normative reference scores for competitive alpine skiers and observations on the development process throughout and beyond athletes' growth spurt are lacking. Thus, the aim of this study was to describe the dynamic knee valgus of competitive alpine skiers during drop jump landings (DJ) and single-leg squats (SLS) with respect to sex, sportive level, and biological maturation. Thirty-seven elite and 104 youth competitive alpine skiers around the growth spurt (U15) were examined for their maximal medial knee displacement (MKD) during DJ and SLS by a marker-based 3D motion analysis evaluating dynamic knee valgus. Additionally, skiers' age, anthropometry and biological maturation were assessed. MKD of youth and elite alpine skiers during DJ was comparable and did not improve with increasing training age. Female U15 skiers (on average further matured) had significantly larger MKD values during DJ than male U15 skiers (less matured) (P < .01). Moreover, MKD during DJ was directly associated with the athlete's individual biological maturation status. MKD values obtained from DJ significantly differed from those obtained during SLS (P < .01). The gender-specific difference in MKD values during DJ and their relationship with maturity offset highlight the fundamental changes to the neuromuscular control system during the growth spurt. Thus, biological maturation needs to be considered as a confounding factor for knee valgus screening. Caution is required when evaluating MKD by using high- and low-dynamic tasks, as corresponding information can differ.     

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.     

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.     

Health problems in youth competitive alpine skiing: A 12-month observation of 155 athletes around the growth spurt

Alpine ski racing is known as a high-risk sport; however, little is known on the health problems occurring at youth level. The purpose of this study was to investigate the prevalence of health problems in youth competitive alpine skiers with respect to sex, age, and season differences, to describe their severity and location and to assess the influence of biological maturation. Over a 12-month period, 155 youth competitive alpine skiers around the growth spurt were prospectively monitored for health problems using the Oslo Sports Trauma Research Centre (OSTRC) questionnaire. These data were verified by supplemental interviews at the end. Biological maturation was estimated by a non-invasive, anthropometric-based assessment method. During competition season, 42.2% of the skiers suffered from health problems and 19.8% reported their problem being substantial. Females had significantly higher rates of acute and overuse injuries compared to males, while there was no sex difference in duration, severity, and time loss. Skiers of the category U15 showed higher prevalence of acute and overuse injuries than U14 skiers. During preparation season, health problem prevalence was substantially lower. The knee was found to be the most affected body part for both acute and overuse injuries. There was a direct association between the offset to the age at peak height velocity (APHV) and the occurrence and severity of acute injuries. In conclusion, youth competitive alpine skiers suffer from a large number of health problems. Since sex, age, and biological maturation are important, effective injury prevention should already start before reaching the APHV.     

Text messaging as a new method for injury registration in sports: A methodological study in elite female football

Methodological differences in epidemiologic studies have led to significant discrepancies in injury incidences reported. The aim of this study was to evaluate text messaging as a new method for injury registration in elite female football players and to compare this method with routine medical staff registration. Twelve teams comprising 228 players prospectively recorded injuries and exposure through one competitive football season. Players reported individually by answering three text messages once a week. A designated member of the medical staff conducted concurrent registrations of injuries and exposure. Injuries and exposure were compared between medical staff registrations from nine teams and their 159 affiliated players. During the football season, a total of 232 time‐loss injuries were recorded. Of these, 62% were captured through individual registration only, 10% by the medical staff only, and 28% were reported through both methods. The incidence of training injuries was 3.7 per 1000 player hours when calculated from individual registration vs 2.2 from medical staff registration [rate ratio (RR): 1.7, 1.2–2.4]. For match injuries, the corresponding incidences were 18.6 vs 5.4 (RR: 3.4, 2.4–4.9), respectively. There was moderate agreement for severity classifications in injury cases reported by both methods (kappa correlation coefficient: 0.48, confidence interval: 0.30–0.66).     

Injuries in Norwegian female elite soccer: a prospective one-season cohort study

Female soccer has become increasingly popular during the last two decades. According to the International Football Association (FIFA) there are approximately 40 million registered female soccer players in the world. Three studies in elite soccer have shown an injury incidence during games ranging from 12.6 to 23.3 injuries per 1,000 h. A very high incidence of ACL-injuries ranging from 0.31 to 2.2 per 1,000 game hours has also been shown. We followed the Norwegian female elite series during the 2001 season to estimate the incidence and characteristics of injuries. A total of 181 female soccer players on ten teams were followed during the 2001 elite season in Norway. We recorded baseline data, match and training exposure and injury data as type of injury, location and severity of injury. The mean age of the players was 23 years (range 17–34). A total of 189 injuries were recorded and 19 (10%) of these were overuse injuries; 89 (47%) occurred during games and 100 (53%) during training sessions. The incidence of acute injuries was 23.6 per 1,000 game hours and 3.1 per 1,000 training hours. The majority of the injuries occurred in the lower extremities (81%), but there were also a significant number of head injuries (6.3%). The most common injury type was ankle sprain (17.2%). Half of the injuries were minor, with training or game absence of less than 7 days. Midfielders sustained the most injuries (32.6%) with an incidence of 42.4 per 1,000 game hours. We recorded two ACL-injuries and two PCL-injuries during the season. They all occurred during games, and the incidence was therefore calculated to 0.6 per 1,000 game hours for both injury types. The incidences of injuries reported for female soccer varies considerably, with the highest numbers reported from Germany and the present study. These studies have also the highest incidence of minor injuries registered. The location of the injuries is quite similar compared to other reports, but the number of ankle sprains seems to be higher in our study, whereas the number of knee and thigh injuries is lower. There has been much attention to ACL injuries in team handball and hamstring injuries in soccer in Norway, and this could have influenced the team’s pre-season training, resulting in a reduction in the incidence of these injury types. The high number of ankle injuries has to be addressed to see whether this is a result of inadequate rehabilitation routines leading to re-injuries, or other factors. The high number of ACL-injuries in these reports is alarming and needs special attention in the future.     

Soccer injuries among elite female players

Injuries occurring in two female elite soccer teams were recorded during 1 year. Of 41 players, 33 (80%) sustained 78 injuries. The incidence of injury during games was 24/1000 hours, while the incidence during training was 7/1000 hours. The majority (88%) of injuries were localized to the lower extremities, with equal occurrence in the left and right legs. Forty-nine percent of the injuries occurred in the knee or ankle. Most of the injuries were minor (49%), while 36% were moderate and 15% were major. Of the major injuries (N = 12), 10 were due to trauma and 7 (58%) were knee ligament or meniscal tears. Overuse injuries constituted 28% of all injuries and occurred mainly during preseason training and at the beginning and end of the competitive season. Traumatic injuries (72%) occurred mainly during games with a predominance at the beginning of the competitive season. Almost 80% of the traumatic injuries occurred during physical contact with an opponent. Extrinsic factors such as weather, playing surface, temperature, or the position of the player within the team did not influence the injury rate. We conclude that female elite soccer players sustain a high incidence of injury. Few injuries were major, but 17% of the players sustained a major knee injury during the year.     

Injuries among Swedish female elite football players: a prospective population study

Injury occurrence in all 12 female elite senior football teams in premiere league was registered during 1 year. Of 269 players, 129 (48%) sustained 237 injuries. The total injury incidence was 4.6/1000 h of football. The injury incidence during practice was 2.7 and during the game time was 13.9/1000 h. The highest injury incidence during practice was to the knee (0.8/1000 h) and thigh (0.5/1000 h), and during game time was to the knee (4.4/1000 h) and head (2.2/1000 h). In total, the location for the highest injury incidence was the knee with 1.5 injuries/1000 h of football. The majority of injuries (82%) were localized to the lower extremities. Sixty-six injuries (28%) were re-occurring injuries (re-injuries). The incidence of traumatic injuries was 3.3/1000 h of football and for overuse injuries 1.3/1000 h. Overuse injuries occurred mainly during the preseason and at the beginning of the spring season. Thirty-nine percent of the injuries were slight or minor causing absence from practice or game time of less than 1 week, 39% were moderate (absence 7-28 days) and 22% were major (absence more than 28 days). The major injuries occurred often owing to trauma and were mainly to the knee.     

Risk factors associated with alpine skiing injuries in children. A case-control study.

We investigated the relative contribution of four risk factors to the occurrence of injuries among alpine skiers aged 12 years and younger (3 to 12 years old; mean age, 9.43 years). The risk factors selected were deficient binding adjustment, absence of formal training, low skill level, and use of rented equipment. A group of injured skiers (N = 41) and a control group of uninjured skiers (N = 313) were recruited among young skiers at one major alpine ski center in the Quebec City, Canada, area during the 1995 to 1996 season. No significant group differences were found for mean age or sex distribution. The adjusted odds ratios for injury were 7.54 (95% confidence interval [2.57, 22.15]) for skiers in the low level of skill category relative to highly skilled skiers, 7.14 (2.59, 19.87) for skiers who rented their ski equipment compared with skiers who owned their equipment, and 2.11 (1.02, 4.33) for skiers with ill-adjusted bindings compared with skiers with better-adjusted bindings. Only formal training did not meet the 0.05 significance level for entry into the model; this is probably because of methodologic limitations. Implications of these results for the development of a prevention program aimed at young skiers are discussed.     

Are oral contraceptive use and menstrual cycle phase related to anterior cruciate ligament injury risk in female recreational skiers?

Oral contraceptive use and menstrual cycle phase are suggested to influence the risk of anterior cruciate ligament (ACL) injuries in female athletes. However, only few data are available for recreational sports. Therefore, female recreational skiers with a non-contact ACL injury and age-matched controls completed a self-reported questionnaire relating to menstrual history, oral contraceptive use and previous knee injuries. Menstrual history data were used to group subjects into either preovulatory or postovulatory phases of menstrual cycle. Our findings suggest that oral contraceptive use did not show any protective effect against ACL injuries nor did self-reported previous knee injuries show any association with ACL injury rate in recreational alpine skiing. Analysis of menstrual history data revealed that recreational skiers in the preovulatory phase were significantly more likely to sustain an ACL injury than were skiers in the postovulatory phase.     

Injuries and preventive actions in elite Swedish volleyball

The purpose of this study was to examine the prevalence of injury and the extent of preventive actions in elite Swedish volleyball players. Injuries to players in the elite male and female Swedish division, during the 2002-2003 season, were registered by using a questionnaire. Of the 158 volleyball players (70% response rate), a total of 82 players (52%) reported 121 injuries, during a total exposure time of 24 632 h, representing an overall incidence of 0.77 injuries per player. The majority of the injuries were located in the ankle (23%), followed by the knee (18%) and the back (15%). Most injuries (62%) were classified as being of minor severity. Most injuries occurred during training (47%), and 41% of the injuries had a gradual onset. Fifty-four percent of the injuries that could be related to a specific court situation occurred during blocking, and 30% during spiking. Most players (96%) participated in injury prevention training of some kind, generally performed without supervision (58%). Although most players took part in some kind of preventive action, one out of two players incurred an injury during the season, which indicates that the risk of suffering an injury in elite volleyball is relatively high.     

Injuries among World Cup ski and snowboard athletes

There is little information available on injuries to World Cup skiers and snowboarders. The aim of this study was to describe and compare the injury risk to World Cup athletes in alpine skiing, freestyle skiing, snowboarding, ski jumping, Nordic combined and cross country skiing. We performed retrospective interviews with the International Ski Federation (FIS) World Cup athletes from selected nations during the 2006–2007 and 2007–2008 winter seasons and recorded all acute injuries occurring during the seasons. We interviewed 2121 athletes and recorded 705 injuries. There were 520 (72%) time‐loss injuries and 196 (28%) severe injuries (absence >28 days). In freestyle skiing, alpine skiing and snowboarding, there were 27.6, 29.8 and 37.8 time‐loss and 14.4, 11.3 and 13.8 severe injuries per 100 athletes per season, respectively. In Nordic combined, ski jumping and cross country skiing, there were 15.8, 13.6 and 6.3 time‐loss and 3.3, 5.6 and 0.7 severe injuries per 100 athletes per season, respectively. In conclusion about 1/3 of the World Cup alpine, freestyle and snowboard athletes sustain a time‐loss injury each season, while the risk is low in the Nordic disciplines. A particular concern was the high proportion of severe injuries observed among alpine, freestyle and snowboard athletes, which is in contrast to most other sports.     

Seasonal deterioration of selected physiological variables in elite male skiers.

The purpose of this study was to determine whether seasonal deterioration in physiological variables could be observed in skiers. Eighteen international male British downhill, free-style, and speed skiers were subjected to a maximal treadmill running test, a 30-s Wingate test, and isokinetic dynamometry at the beginning, middle, and end of the 1989-90 competition season. Maximal oxygen intake (VO2max) and respiratory anaerobic threshold (T vent) were among the parameters measured on the treadmill test, while peak and mean power outputs were measured during the Wingate test. During dynamometry, knee flexors and extensors were bilaterally assessed at 1.04 and 3.14 rad.s-1. Mean VO2max (p < 0.01) and mean T vent (p < 0.05) were lower at the end compared to the beginning, but not compared to the middle of the competition season. The isokinetic test demonstrated lower mean peak torques at 1.04 rad.s-1, for the knee extensors measured at the end of the season, compared with both the start (p < 0.01) and the middle (p < 0.05). Also at 1.04 rad.s-1, knee flexors produced lower torques at the end than the start of the season (p < 0.05). No further statistical differences were found. It was concluded that seasonal deterioration in key physiological variables such as aerobic endurance and muscle strength, can be observed in elite alpine skiers, and that in-season fitness training programmes should take account of this.