A 3D analysis of the joint torques developed during driver's Ingress-Egress motion

Providing an easy ingress-egress movement (I/E) remains a challenge for car designers. I/E has been largely studied in kinematics, but not in dynamics. This study proposes: 1/ to evaluate and describe the motor torques developed in the lower limbs and lumbar joints during I/E motions and 2/ to analyse the influence of the car geometry and subject anthropometry. An experiment was performed to observe 15 subjects of three anthropometrical groups getting in and out of a car mock-up simulating three different vehicle configurations. Motor torques were extracted using an inverse dynamics analysis. Both ingress and egress motions were primarily characterized by large torques. Overall, the taller a subject and the lower the seat of the vehicle were, the larger the peak torques were. Moreover, peak torques were higher for egress than ingress. These results are discussed in regards of the current knowledge on I/E ergonomics