Context: Sex differences in landing biomechanics play a role in increased rates of anterior cruciate ligament (ACL) injuries in female athletes. Exercising to various states of fatigue may negatively affect landing mechanics, resulting in a higher injury risk, but research is inconclusive regarding sex differences in response to fatigue.
Objective: To use the Landing Error Scoring System (LESS), a valid clinical movement-analysis tool, to determine the effects of exercise on the landing biomechanics of males and females.
Design: Cross-sectional study.
Setting: University laboratory.
Patients or other participants: Thirty-six (18 men, 18 women) healthy college-aged athletes (members of varsity, club, or intramural teams) with no history of ACL injury or prior participation in an ACL injury-prevention program.
Intervention(s): Participants were videotaped performing 3 jump-landing trials before and after performance of a functional, sportlike exercise protocol consisting of repetitive sprinting, jumping, and cutting tasks.
Main outcome measure(s): Landing technique was evaluated using the LESS. A higher LESS score indicates more errors. The mean of the 3 LESS scores in each condition (pre-exercise and postexercise) was used for statistical analysis.
Results: Women scored higher on the LESS (6.3 ± 1.9) than men (5.0 ± 2.3) regardless of time (P = .04). Postexercise scores (6.3 ± 2.1) were higher than preexercise scores (5.0 ± 2.1) for both sexes (P = .01), but women were not affected to a greater degree than men (P = .62).
Conclusions: As evidenced by their higher LESS scores, females demonstrated more errors in landing technique than males, which may contribute to their increased rate of ACL injury. Both sexes displayed poor technique after the exercise protocol, which may indicate that participants experience a higher risk of ACL injury in the presence of fatigue.
Keywords: Landing Error Scoring System; anterior cruciate ligament; fatigue.