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.

In recreational alpine skiing, ACL injury risk is 3 times greater in females. However, since the introduction of carving skis ACL injury risk seems to have decreased. No study has yet investigated the distribution of ACL injury mechanisms in male and female carving skiers. Therefore, the aim of the study was to investigate potential gender specific differences of ACL injury mechanisms and related factors among carving skiers. In total, 220 recreational carving skiers (59 males and 161 females) suffering from an ACL injury volunteered for this study. Demographic data, skiing ability, equipment related and environmental factors, circumstances and causes for the fall, and type of fall (injury mechanisms) were collected by questionnaire. The forward twisting fall is the most reported ACL injury mechanism in both gender (p=0.672) accounting for 54% of all injuries, although male and female skiers differed significantly with regard to circumstances of fall (p=0.001) and actions when ACL injury occurred (p=0.04). Bindings not releasing at the time point of accident occurred 2.6 times more with females than with males (p=0.005). The forward twisting fall seems to have become the dominant ACL injury mechanism both in male and female recreational skiers since the introduction of carving skis.

While ACL injury mechanisms in skiers using traditional skis are well studied, no study has yet investigated the distribution of injury mechanisms in carving skiers. In traditional skiers, the backward twisting fall seems to be the dominant injury mechanism, especially in female skiers. Female recreational skiers have a threefold higher risk to sustain an ACL injury than male skiers; therefore, it is important to determine if carving skis influence the distribution of injury mechanisms and the related frequencies of ACL injuries in female skiers. We investigated the frequencies of injury mechanisms and related factors in 65 ACL-injured female carving skiers by questionnaire. The forward twisting fall was the most reported ACL injury mechanism with about 51%, followed by the backward twisting fall within 29% of cases. Catching an edge of the ski (59 vs. 24%, P = 0.03) when executing turns (69 vs. 41%, P = 0.053) was a more frequent cause for forward twisting falls than for the other types of falling. While 29% of bindings released during a forward twisting fall, only 3.1% released during the remaining mechanisms. In contrast to traditional skiers, the forward twisting fall was the dominant injury mechanism in female carving skiers with ACL injury.

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.