Kinematics and dynamics of pedestrian head ground contact: A cadaver study.

• First detailed analysis of pedestrian ground contact kinematics using cadaver tests. • The linear accelerations in ground contact are generally higher. • Highlighting the risk of pedestrian injuries from ground contact at low speeds. Pedestrians struck by vehicles are generally injured by the primary vehicle contact but also the secondary ground contact. However, experimental evidence for ground contact injuries is limited. Here we report on six staged cadaver tests at 20–30 km/h with passenger cars/vans in which we recorded the whole process from first pedestrian contact until after the end of the ground contact is complete using high-speed video and accelerometers mounted in the cadavers. Results show distinct phases for pedestrian flight and ground contact in addition to the already established vehicle contact phases. No skull fractures were observed in any of the tests. However, for the speed range tested, the linear and angular head injury risk (evaluated using HIC/3ms & BrIC respectively) is generally higher from the ground contact compared to the vehicle contact. Although not yet clearly understood, angular head injury risk during ground contact is higher for the 20 km/h tests compared to the 30 km/h tests. A good comparison was observed with respect to previously predicted ground contact mechanisms and head impact speeds from multibody modelling. These results emphasize the importance of ground related injuries to pedestrians when struck by vehicles at speeds of 20–30 km/h and provide a unique dataset for computational model validation of pedestrian ground contact. [ABSTRACT FROM AUTHOR]