Whiplash neck injuries among drivers and their passengers who have been shunted from behind are a major cause of long-term health problems and, in extreme cases, death. A report in International Journal of Vehicle Systems Modelling and Testing describes a new type of vehicle headrest that can both improve safety and comfort.
The new headrest being developed by Italian engineers can be easily positioned so that it is always at the optimum passenger head distance to avoid whiplash injuries during a rear vehicle collision. However, the headrest almost instantaneously locks in position during a crash and provides the best protection for driver and passengers.
Federico Giorgetta, Massimiliano Gobbi, and Giampiero Mastinu of the Department of Mechanical Engineering, at the
Gobbi and colleagues explain their motivation: "Whiplash injuries constitute a growing health problem and economic burden in westernised and motorised nations," and suggest that, "Without significant efforts in crash prevention and improvements in vehicle safety design, especially with more effective seat back and head restraint systems, the ever increasing traffic density will show a rise in this negative trend."
Part of the problem is the drivers and their passengers are unaware of the personal harm a whiplash injury can do and usually fail to adjust their headrest to the optimum height. Moreover, common headrests are often difficult to adjust and are pressed downwards by the head in a collision and so do nothing to save the person from injury. A headrest that can be adjusted without fuss to the optimum safety and comfort level is needed, the team says. The team has studied the biomechanics of whiplash injury, so named because of the way the head moves when involved in a rear-end collision.
They explain that whiplash is an issue of rapid "acceleration-deceleration" with energy transferred to the neck in rear-end or side-impact collisions. A whiplash can cause bone and soft-tissue injuries that may or may not be treated effectively. Such injuries are preventable with better headrest design the team believes.
They have developed full-scale tests and a scaled test-rig for research and development of the new headrest prototype. The new headrest has an automatic locking system that is activated only in a collision, locking the headrest within milliseconds. At other times, the headrest is unrestrained and can be adjusted without difficult manoeuvres involving the depression of various locking buttons.