Quantifying posture differences between wheelchair users and standard automotive posture

Vehicles with automated driving systems may provide substantial benefits to individuals who travel while seated in wheelchairs. Despite the importance of posture data for developing occupant protection systems, limited research has analysed wheelchair user posture in the context of automotive safety. In this study, we obtained three-dimensional postural data of 75 people seated in their personal wheelchairs and generated individualised baseline avatars in automotive posture using HumanShape software. Generated avatars were manually adjusted to match the posture of the field scan, and anatomical landmark locations and segment orientations were analysed relative to wheelchair and participant characteristics. Observed differences in pelvis, abdomen, and knee angles compared to standard automotive posture indicate the prevalence of reclined posture among wheelchair users offset by a more forward neck angle. Significant postural differences were observed based on gender, BMI, and disability. These posture differences have implications for the design of occupant protection systems.