Increased Trunk Motion In Female Athletes Compared To Males During Single Leg Landing

Abstract

PURPOSE: Core stability has been denned as the ability to control the position and motion of the trunk during athletic activities (Kibler 2006). Decreased active trunk control may increase risk of injury to the distal joints, specifically the knee. The purpose was to examine trunk motion in height and weight matched athletes during a single leg landing maneuver. The hypothesis was that females would exhibit increased trunk motion compared to males and that this motion would correlate with differences in lower extremity joint mechanics. METHODS: 11 female (F) and 11 male (M) collegiate basketball and soccer athletes height (F: 176±8cm; M: 176±8cm) and weight (F: 73±7 kg; M: 74±6 kg) matched were measured using 3-D motion analysis. Trunk and lower extremity joint angular motions, moments and powers were calculated during single leg landings (from initial ground contact to maximum center of mass displacement) from a medial drop of 13.5 cm. Each leg was examined separately using a MANO VA to determine the differences between sexes. Pearson correlation coefficients were utilized to determine the relationship between variables. RESUITS: Females demonstrated increased maximum trunk flexion (F: −13.9±8.0°; M: −8.5±6.6°; P=0.02), total trunk flexion range of motion (ROM)(F: 10.1±4.1°; M: 6.2±2.7°; P<0.001) and lateral trunk tilt ROM (F: 3.8±1.9°; M: 2.8±1.3°; P=0.042) compared to males during landing. Increased sagittal plane trunk ROM was significantly correlated to a decreased knee extensor (internal) moment in both groups of athletes (R=0.61, P<0.001). Females also demonstrated decreased knee extensor moment compared to males (F: −1.66±0.45Nm/kg; M: −1.91±0.33Nm/kg; P=0.036). No other sagittal plane variables in the lower extremity were different between gender. CONCLUSIONS: This study demonstrates that measures of active trunk control are different between males and females during single leg landing tasks. Female athletes demonstrate decreased dynamic control of their trunk compared to males as evidenced by increased trunk ROM in the sagittal and coronal planes during single leg landing. These observations may be indicative of a compensation for decreased dynamic coupled stability of the trunk and knee. Trunk mechanics should be considered when examining knee motion and torque in female athletes.