Sex differences in gluteal muscle forces during running.

Sex differences in common sports injuries to the lower extremity have been reported. Biomechanical factors of the hip have been investigated between sexes with regard to running-related injury. This study investigates gluteal muscle forces between sexes to aid in our understanding of sex-related biomechanical factors in running. Twenty-one healthy male and female runners were participants. Each ran at a controlled speed of 3.52-3.89 m/s down a 20-m runway. Kinetic and kinematic data were utilised to estimate muscle forces. Multivariate analysis of variance tests were utilised to detect differences in gluteal and hamstring muscle forces, hip and pelvic kinematics, and hip kinetic variables between sexes. Males produced greater peak gluteus maximus force, but lesser peak gluteus medius, minimus, and hamstring force than females during running. Males also demonstrated less hip adduction and greater hip flexion and anterior pelvic tilt than females. Finally, males produced lesser peak hip abduction and external rotation moments than females. Males and females demonstrate differences in gluteal muscle forces and hip kinetics and kinematics during running. Further understanding of underlying muscle forces may offer further insight into biomechanical differences in running between males and females.