Exponent has extensive expertise and capabilities in human motion modeling and simulation. Simulations are used to evaluate human motion and injury potential in a wide variety of cases, including motor vehicle collisions, pedestrian accidents, bicycle accidents, falls, and other types of accidents. Our biomechanical engineers use state-of-the-art computer simulation programs, such as MADYMO® (TNO Automotive Safety Solutions), to analyze dynamics of the human body under varying impact/crash conditions. MADYMO®, an acronym for Mathematical DYnamic MOdel, is a sophisticated computer program that has been used for many years to simulate human motion during dynamic events, especially occupant kinematics during motor vehicle collisions. Our biomechanical engineers also have experience with ATB. ATB (Articulated Total Body) is a dynamic simulation tool that also can simulate human motion during dynamic events. We continue to perform and publish ongoing research using human motion modeling and simulation.
Occupant Kinematics 
Exponent’s biomechanics professionals simulate occupant kinematics resulting from a wide array of vehicle motions. We frequently use complex accident histories obtained from crash tests and collision simulations to determine the kinematics of single and multiple occupants, and to evaluate injury mechanisms. Our team has extensive experience in simulating occupant kinematics in frontal impacts, rear impacts, side impacts, multiple rollovers, and combinations of such. We are current with Federal Motor Vehicle Safety Standards (FMVSS), United Nations Economic Commission for Europe (UNECE) vehicle regulations, and the Federal Aviation Administration (FAA) airworthiness standards. Our consultants have successfully created numerical models using MADYMO® to simulate these test conditions.
Occupant Restraint Performance
Our experience includes modeling and evaluating the effectiveness of occupant restraint systems such as seatbelts, front airbags, side airbags, and side curtains. We have experience with modeling inflators and have evaluated inflator/airbag performance to optimize the protection offered by the airbag systems. Our team has the ability to capture the complex interactions between the occupants and the restraint systems with a high degree of accuracy. We have created MADYMO® models to evaluate restraint-system performance for automotive and aerospace applications. Our expertise also includes modeling restraint systems for specialized applications, such as military vehicles, racing cars, and ejection seats of fighter jets.
Other Vehicle Accidents
Exponent’s biomechanical engineers have experience reconstructing Go-Kart accidents, bicycle accidents, vehicle-to-bicycle accidents, and vehicle/pedestrian accidents using MADYMO® models. For instance, bicycle simulations have been used to analyze rider kinematics and injuries resulting from collisions with fixed objects. Vehicle/bicycle and vehicle/pedestrian simulations have been used to analyze vehicle speeds and timing issues. We have also evaluated injury claims related to incidents involving amusement park rides, including capturing human motion and loading and evaluating injury potential. We also assist clients in designing cabin structure, seats, and restraint systems for rides involving high speeds and g-forces, such as roller coasters and Go-Karts.
Other Accidents
Exponent’s modeling and simulation experience also includes the analysis of human motion during a wide variety of other non-vehicle accidents, including trips, slips, falls, and human/machine interactions. We simulate falls down stairs, falls from height, and human motion and injuries resulting from agricultural and industrial accidents.
Analysis of Simulations
Accurately simulating real-world scenarios requires not only expertise in the software, but also experience in modeling a variety of situations. Our team has decades of experience with both, and therefore are able to examine existing simulations for accuracy and validity.
Figure 1. This series of figures depicts a MADYMO® model of a lateral collision involving a seatbelted child occupant. Our analysis included validation of the simulated vehicle dynamics using a crash test, as well as validation of the occupant-to-vehicle interaction using sled testing. This analysis allowed for determination of the occupant kinematics in the subject collision, which provided additional insight into occupant injury mechanics.