How speed, incline and fatigue alter pelvic kinematics in female running

Running provides health benefits but also carries an injury risk. While speed, incline, and fatigue affect running biomechanics, their influence on pelvic kinematics in female runners remains underexplored. This study examined how these factors impact three-dimensional pelvic rotation, tilt, and obliquity in female heel-strikers. Twenty-five female runners completed randomized treadmill sessions at speeds of 10, 12, and 14 km/h and inclines of 0%, 5%, and 10%, before and after a 30-minute fatiguing protocol. Kinematic data from 14,800 steps were collected via motion capture and analyzed using a mixed-effects model. Increased speed significantly elevated peak pelvic rotation, rotation range of motion, pelvic tilt, and obliquity range of motion (all p < 0.001). Steeper inclines increased peak pelvic rotation (p = 0.002) and obliquity (p = 0.004) while reducing anterior pelvic tilt post-fatigue (p = 0.004). Fatigue significantly increased peak pelvic rotation and pelvic tilt range of motion (both p < 0.001). These findings highlight the importance of monitoring pelvic kinematics in female runners to reduce injury risk. Adjusting running speed to minimize excessive pelvic motion, optimizing incline selection to reduce chronic strain injuries, and incorporating strength training to mitigate fatigue-related biomechanical changes.