Sex Differences In Lower Extremity Kinematics During Overhead And Single Leg Squat Tests

Abstract

The Overhead Squat (OHS) and Single-Leg Squat (SLS) are two clinical tests commonly used by sports medicine practitioners to identify high-risk biomechanical movement patterns. Traditional scoring of these tests requires subjective judgement whereas new technology has allowed for automatic scoring and additional objective data. To date, few studies have examined sex differences in OHS and SLS performance and none measured with a marker-less motion capture system. PURPOSE: To determine if biomechanical differences exist between male and female collegiate athletes during performance of an OHS and SLS. METHODS: 75 female (18.1±0.4y; 166.9±6.5cm; 64.1±10.2kg) and 58 male (18.7±1.2y; 184.4±7.1cm; 86.9±15.2kg) collegiate athletes completed OHS and SLS testing as part of their pre-participation exam. Men’s sports included football (n=24), baseball (n=19), lacrosse (n=10), and swimming (n=5); women’s sports included track and field (n=23), field hockey (n=12), softball (n=12), lacrosse (n=9), swimming (n=7), soccer (n=6), golf (n=3), tennis (n=2), and gymnastics (n=1). Participants completed 4 OHSs followed by 4 SLSs on each leg. A Microsoft Kinect sensor using Athletic Movement Assessment software (PhysiMax®) was used to measure all kinematic variables. Differences between males and females were assessed with independent t-tests. RESULTS: For the OHS, males displayed greater peak knee varus (M: 25.7°±9.6°, F: 19.8°±8.2°; P<0.001), peak hip flexion (M: -93.6°±-14.41°, F: -86.9°±-14.5°; P<0.05), and peak trunk flexion angles (M: 11.5°±10.9°, F: 6.3°±9.2°; P<0.01). Females displayed greater peak ankle dorsiflexion angles (F: -28.7°±-5.8°, M: -26.5°±-6.3°; P<0.05). For the SLS (dominant limb), males displayed greater peak trunk flexion (M: 32.2°±5.6°, F: 27.6°±6.6°; P <0.001) and lateral pelvic angles (M: 4.2°±3.9°, F: 2.9°±2.7°; P<0.05). For the non-dominant limb, females displayed greater peak knee valgus angles (F: -12.5°±-9.1°, M: -8.9°±-9.1°; P<0.05) whereas males displayed greater peak trunk flexion angles (M: 31.7°±5.5°, F: 27.5°±6.9°; P<0.001). CONCLUSION: Male and female collegiate athletes displayed different movement strategies during performance of an OHS and SLS. Injury prevention programs may need to target sex-specific biomechanical patterns to improve movement capacity.