Are there Sex Differences Regarding Ski Length to Height Ratio, Ski Length to Weight Ratio, Sidecut Radius and Ski Boot Sole Abrasion among ACL Injured Male and Female Skiers?

Abstract

Introduction Female skiers suffer from knee injuries twice as much as male skiers, and the risk of an injury to the anterior cruciate ligament (ACL) is three times greater among females compared to males. The sex-specific ACL injury risk depends on internal (e. g. age, skiing skills, fitness level) and external (e. g. slope and weather conditions, ski equipment) factors. However, it is not clear whether male and female recreational skiers with an ACL injury differ regarding the sidecut radius and ski boot sole abrasion. Method This questionnaire-based study was conducted in the winter seasons 2014/15 and 2015/16. During those periods, data of ACL-injured skiers were collected at an Austrian ski clinic. The questionnaire included information about demographics, skiing skills, type of fall, binding release, and injury diagnosis. Furthermore, the ski length and sidecut radius were notated from the ski, and abrasion of ski boot sole was measured at the toe and heel piece of the ski boot using a caliper. Results In total 164 ACL-injured skiers (67 % females) with a mean age of 41.7 ± 11.5 years were recorded. Males used significantly longer skies compared to females (168.3 ± 6.6 vs. 157.5 ± 5.9 cm, p < 0.001), however the ski length to height ratio (94.0 ± 3.4 vs. 94.1 ± 3.3 %) showed no significant difference between the two sexes. The ski length to weight ratio was significantly different between females and males (2.5 ± 0.3 vs. 2.0 ± 0.2 cm/kg). The sidecut radius (13.5 ± 1.4 vs. 15.6 ± 2.6 m, p < 0.001) was significantly lower among ACL-injured females compared to ACL-injured males. No sex-specific differences were found regarding the abrasion of ski boot soles, neither at the toe piece (5.4 ± 1.2 vs. 5.5 ± 1.1 mm) nor at the heel piece (6.0 ± 1.7 vs. 6.0 ± 1.6 mm) between females and males. For both sexes the most common type of fall was the forward fall with body rotation (approximately 59 %). Failure of binding release was significantly more often reported by females compared to males (86 vs. 44 %, p < 0.001). Conclusion Female and male skiers with an ACL injury differ regarding the sidecut radius, the ski length to weight ratio, and the proportion of failure of binding release. Moreover, although no sex-specific differences were found regarding the abrasion of ski boot soles, the mean ski boot abrasion was beyond the ISO standard tolerances.