Motorcycle rider posture prediction: The prediction of spinal curvature as a function of anthropometrics and point-of-contact chassis design

This research developed a significant motorcycle rider posture prediction capability that relates individual anthropometrics and motorcycle chassis point-of-contact design to the curvature of the spine. This research is a step towards integrating Human Factors and Ergonomics (HFE) as a normal and practical engineering process within motorcycle chassis design. The research was divided into three divisions to build a systematic body of knowledge about motorcycle rider posture. The first division was an initial biomechanical investigation into motorcycle design and an assessment of the moments that push and pull the pelvis, sacrum, and lumbar region of the spine to assume various postures. The second division was a preliminary experiment amassing over 600 subject matter expert responses to an in-depth motorcycle rider posture survey. Findings from this preliminary experiment set an azimuth for continued research, developing initial qualitative relationships and providing insight into what the experts think about chassis design, modification requirements, comfort, and the ability to attain comfort on a motorcycle. The third division of this research was a set of three quantitative experiments that collected detailed spinal and 5-link human representation location data along with anthropometrics of subjects and motorcycle chassis point-of-contact locations. The intent of this data collection effort was the exploration and formulation of a significant relationship between factors that influence the curvature of a human spine while seated on a motorcycle.; The result is a significant mathematical capability that predicts the horizontal location for any given vertical location on a rider's vertebral column relative to the rider's anthropometric descriptive information and the chassis point-of-contact design. Once a set of locations is predicted, the set represents discrete points along the curve of a spine. Inversely, specifying a set of locations that represent a desired curve can provide the predicted chassis point-of-contact locations. This relationship between anthropometrics and motorcycle chassis design will enable the chassis engineer to make quantitative choices with respect to expected resultant postures when designing the point-of-contact locations on a chassis and it may provide a revolutionary method to design a more universal chassis that fits a larger proportion of the anthropometrically defined population.