Objective: To examine sex differences in strength, Q-angle, and pronation as predictors of anterior cruciate ligament (ACL) injuries.
Design and setting: Height, weight, sum-of-seven skin-folds, quadriceps and hamstrings strength, Q-angle, and pronation were measured in each subject.
Subjects: Male (n = 23) and female (n = 25) NCAA Division in identical conditioning programs.
Measurements: Strength was measured at 180 degrees .s(-1) using an isokinetic dynamometer. Q-angle was assessed with the leg fully extended and flexed to 30 degrees . Pronation was determined with the navicular drop test.
Results: A 2 x 2 factorial analysis of variance indicated significant differences in the eccentric hamstrings-to-eccentric quadriceps strength ratio (female right = 46.11% +/- 2.83%, left = 52.73% +/- 3.74%; male right = 89.08% +/- 6.34%, left = 93.16% +/- 9.14% (P < .001)) and Q-angle measured in 30 degrees of flexion (female right = 13.37 degrees +/- 0.99 degrees , left 15.56 degrees +/- 1.34 degrees ; male right = 5.62 degrees +/- 0.75 degrees , left = 6.00 degrees +/- 0.86 degrees (P = .05)).
Conclusions: The results of this investigation indicate that, of the variables thought to contribute to ACL injuries, eccentric hamstrings strength relative to concentric quadriceps strength and Q-angle measured in 30 degrees of flexion appear to be significantly different in males and females.