Jump-Landing Kinematics: Establishing Normative Ranges for Male and Female Athletes

Abstract

Context: Lower extremity (LE) joint kinematics during landing tasks are important predictors of injury risk and performance outcomes in athletes. Objective: To establish sex-related differences and normative ranges for LE kinematics during the jump-landing task in a large cohort of healthy military service academy cadets. Design: Cross-sectional study. Setting: US Air Force, Military, and Naval academies. Patients or Other Participants: A total of 5308 cadets comprising 2062 female (38.8%; age = 18.57 ± 0.79 years, height = 165.61 ± 6.5 cm, mass = 62.9 ± 7.95 kg) and 3246 male cadets (61.2%; age = 18.87 ± 0.97 years, height = 178.13 ± 7.13 cm, mass = 77.59 ± 12.4 kg) participated. Main Outcome Measure(s): Sex-related differences in LE kinematics during the jump-landing task were analyzed using an independent-samples t test. Mean differences (MDs) and Cohen d effect sizes were reported for interpretability. Normative ranges for hip- and knee-joint angles were established separately for male and female cadets at initial contact (IC) and 50% of the stance phase. Results: Moderate effect sizes were observed for knee- external-rotation angles, for which female cadets had greater motion at IC and at 50% of stance (MDs = -3.91° and -5.04°, respectively; P