Posture variation in a car within the restrictions of the driving task

Passive posture variation in vehicles could enable variation in pressure distribution and muscle activity to counter physical fatigue from static seating resulting in more comfort. The difference in posture, however, should not lead to perceived discomfort and aspects of driving should be considered such as operating the steering wheel, pedals and vision in the mirrors.

This study sets out to find out how much postural variation occurs during the driving task and how sensitive is the human body to these changes.

The first experiment was user evaluation and assessed how and when the changes in seat configuration were noticeable to the human body. The second experiment evaluated the influence of varying inclination of the backrest and the seat pan by the rating of typical aspects of driving.

The differences in seat configuration during experiment 1, were so small that there was no consistency in the ratings for the same configuration. The most critical feature that restrains the posture is the location of the rear view mirror.

The range-of-motion is defined as -1° to +1° for the seat pan and 0° to +1.5° for the backrest based on the results of experiment 2 because of the restraints of the driving task.