Sex-specific analysis of individual and ski geometry-related risk factors for ACL injuries in recreational alpine skiing: A case-control study

Abstract

Introduction In recreational alpine skiing, female skiers experience knee injuries at twice the rate of male skiers, with the risk of anterior cruciate ligament (ACL) injuries being three times higher in women (Posch et al. 2021). In addition to individual factors such as, e.g., age or skill level, ski geometry parameters may also influence the risk of ACL injuries (Ruedl et al., 2022). Therefore, the aim of this study was to assess sex-specific effects of individual factors and ski geometry parameters on ACL injury risk in recreational skiers.

Methods A retrospective questionnaire-based case-control study was conducted during 6 consecutive winter seasons from 2014/15 to 2019/20. According to Ruedl et al. (2022) individual factors as age, body height, skill level and risk-taking behavior were self-reported, while ski geometry data (ski length, side-cut radius, and widths of the tip, waist, and tail) were recorded from each participant’s skis. Additionally, ski length was relativized to body height.

Results A total of 1,817 recreational skiers (49.1% female) participated in this study, of whom 21.6% (n=392, 57.9% female) sustained an ACL injury. The risk of ACL injury was 1.6 times higher in females (95% CI: 1.2-2.0). In both sexes, ACL-injured skiers were significantly older, by approximately five years, compared to uninjured controls (females: 42 vs. 37 years; males: 44 vs. 39 years). In females, a more risky behavior was associated with a reduced ACL injury risk (OR 0.7, 95% CI: 0.4-0.9), while in males, more risky behavior increased the risk (OR 3.5, 95% CI: 2.4-5.0). A lower skill level increased ACL injury risk in both females (OR 3.2, 95% CI: 2.4-4.6) and males (OR 2.2, 95% CI: 1.5-3.2). Ski geometry parameters did not differ significantly in females; however, ACL-injured males used skis with significantly narrower mean values of tip, waist, and tail width compared to uninjured controls.

Discussion/Conclusion According to the existing literature, our findings indicate a significantly higher risk of ACL injury in females. Increasing age and lower skill levels were associated with a heightened ACL injury risk in both sexes, while a risky behavior might increase ACL injury risk in males only. Ski geometry parameters appear to have no significant impact on ACL injury risk in females, whereas males with ACL injuries tended to use skis with narrower widths. In addition to enhancing skill levels through ski lessons and modifying individual behavior on the slopes to reduce ACL injuries among recreational skiers of both sexes, equipment-related factors could be easily addressed by male skiers when purchasing or borrowing ski equipment.

References

Posch, M., Schranz, L., Lener, M., Tecklenburg, K., Burtscher, M., & Ruedl, G. (2021). In recreational alpine skiing, the ACL is predominantly injured in all knee injuries needing hospitalisation. Knee Surgery, Sports Traumatology, Arthroscopy, 29(6), 1790–1796. https://doi.org/10.1007/s00167-020-06221-z

Ruedl, G., Posch, M., Tecklenburg, K., Schranz, L., Greier, K., Faulhaber, M., Scher, I., & Burtscher, M. (2022). Impact of ski geometry data and standing height ratio on the ACL injury risk and its use for prevention in recreational skiers. British Journal of Sports Medicine, 56, 1104-1109. https://doi.org/10.1136/bjsports-2021-105221