The relationship between ACL injuries and physical fitness in young competitive ski racers: a 10-year longitudinal study

Br J Sports Med. 2012 Dec;46(15):1065-71. doi: 10.1136/bjsports-2012-091050. Epub 2012 Sep 11.


Background: Epidemiological studies have shown a high incidence of anterior cruciate ligament (ACL) injuries among competitive alpine skiers. Little is known regarding modifiable risk factors in young skiers. There are still uncertainties in gender-related risk factors.

Objective: The purpose of this study was to determine the relationship between ACL injuries and internal risk factors.

Methods: Retrospective data analyses were performed based on a group of 175 female and 195 male alpine ski racers between the ages of 14 and 19 years. The athletes underwent physical testing annually from 1996 to 2006. Z score transformations normalised the age groups. Multivariate binary logistic regressions were calculated for men and women separately to detect significant predictors of ACL ruptures. t Tests were computed to reveal the differences in test scores between injured and non-injured athletes.

Results: A total of 57 (15%) ACL injuries occurred. The female-male risk ratio (RR) was higher in females (2.3, 95% CI 1.3 to 4.2). Z scores for relative leg force, ratio of absolute core flexion to extension force, relative core strength and reactive strength index were predictive variables for men. Z scores of all of these predictive variables except relative leg force were higher in the non-injured group. The ratios of absolute flexion to extension force and absolute core strength were predictive covariates for women. Z scores for absolute core strength were higher in the non-injured group.

Conclusions: The risk of ACL injury was greater in female athletes. The findings suggest that core strength is a predominant critical factor for ACL injuries in young ski racers.

MeSH terms

  • Adolescent
  • Age Distribution
  • Anterior Cruciate Ligament Injuries*
  • Anthropometry
  • Case-Control Studies
  • Exercise Test / methods
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Physical Fitness / physiology*
  • Risk Factors
  • Rupture / etiology
  • Sex Factors
  • Skiing / injuries*
  • Young Adult