[Automobile head supports--adjustment possibilities and utilization. Results of a field study]

An important detail referring to the whiplash syndrome is the relationship between the position of the head restraint and the head, because the head restraint protects the head in case of a rear-end accident. This relationship was evaluated in a representative study in 601 nonselected volunteers. A horizontal distance between the head and head restraint of maximal 9 cm was present in 69.6%. An optimal distance of 0 cm was only found in 7.4%. Just 50% of the adjustment distance was used by the car drivers. Even in completely distracted adjustments in 50% a deficit of more than 8 cm, and in 20.9% a deficit of even more than 12 cm was present. These results show that passive protection, on the one hand, is not guaranteed because of the lack of proper height adjustment. On the other, the volunteers did not use the best adjustment each time.