The impact of joint angle and movement velocity on sex differences in the functional hamstring/quadriceps ratio

Background: Females are two to eight times more likely to suffer a non-contact injury compared with males thus the purpose of this study was to explore the influence of joint angle and movement velocity on sex differences in the functional hamstring to quadriceps ratio (H/Q(FUNC)). Methods: lsokinetic concentric and eccentric torque were determined in 110 participants (55 males and 55 females) through a 90 degrees range of movement at 60, 120, and 240 degrees/s. Testing was performed with the hip flexed at 10 degrees. The H/Q(FUNC) was determined at three specific joint angles (15, 30 and 45 degrees flexion) and where peak torque occurred for concentric knee extension. Results: A significant interaction effect (P < 0.01) for sex and joint angle was observed with women demonstrating a lower H/Q(FUNC) than males, especially at more extended knee positions. A significant sex by velocity interaction (P < 0.01) indicated a lower H/Q(FUNC) in women as velocity increased. Significant main effects (P < 0.01) indicated that irrespective of sex the H/Q(FUNC) increased as the knee extends and velocity increases. Conclusion: Given the reduced H/Q(FUNC) in females compared to males at more extended knee positions and faster velocities, this may contribute to the observed sex bias in reported injury rates. (C) 2017 Elsevier B.V. All rights reserved.