Whiplash Possible At Low Speeds, But Psyche A Factor In Injury Claims: Expert

"Once a rear collision velocity change approaches six miles per hour, we start to see soft tissue symptoms," said Ms. Haddox.

"A common misconception is that no vehicle damage equals no injury potential. This is not necessarily the case," she said.

Low-speed rear-end impacts are among the most common types of vehicle collisions and result in millions of dollars in claims each year, according to Ms. Haddox. Whiplash Associated Disorder is responsible for a large percentage of these claims, she added.

Because the standard dummy used in most crash tests has a stiff neck configuration, two specialized rear-impact dummies have been developed with more flexible spinal configurations. The BioRID II and RID2 have performed relatively well and are in regular use in research on low-speed occupant kinematics and injury prevention.

"In some ways, the dummies have made progress simulating the performance of human subjects; and in some ways, theyve made no progress at all," said Ms. Haddox. "Theres still some work to do on these rear-impact dummies."

Because differences in force distribution between the dummy tests and human volunteer tests may affect the use of dummies for injury prediction, testing with volunteers remains the most accurate method for predicting occupant response in low-speed rear-end impacts, she said.

Recent human subject testing has involved an investigation of a possible psychosomatic element of accident injuries, she explained.

In one German study, the subjects view to the rear of the test vehicles was blocked. The rearward car was driven forward and braked severely, causing noise, but no actual impact. At the same time, a heavy weight was dropped on a glass bottle in the trunk of the subject vehicle, which was allowed to roll down a small incline. No actual impact occurred, and the average vehicle acceleration was much less than average driver acceleration from a traffic light or stop sign.

Following the simulations, 12 of the 51 subjects reported symptoms within three days, with one reporting continuing symptoms 28 days after the event. "It appears clear from this study that there is a psychological component in some injuries reported after low-speed rear-end collisions," said Ms. Haddox.

Another recent study investigated the effect of volunteer subject awareness, comparing reactions among groups of alerted, non-alerted and surprised subjects. The alerted group received a countdown, while the non-alerted group was told to expect an impact within 60 seconds. The surprised group was deceived; they were told that a baseline muscle measurement was needed, and the event occurred while the baseline measurement was being taken.

The results of this study showed no significant differences in kinematic response between alerted and unalerted subjects, and only slight differences in some of the responses of surprised subjects. For example, surprised females exhibited slightly greater rearward head motion than alerted or unalerted females, while surprised males exhibited slightly greater rebound head acceleration than alerted or unalerted males.

The ACE-SCLA Annual Claims Exposition + Conference was presented by Claims Magazine. Claims Magazine is published by The National Underwriter Company, which is also the parent company of this newsmagazine. The Conference was produced in conjunction with the Society of Claims Law Associates, a national organization of claims people whose purpose is to promote professionalism through education.

For a more detailed account of research being done in this area, read Ms. Haddoxs article in the December issue of Claims.

Mikel Benton is a senior editor for Claims magazine.

Reproduced from National Underwriter Property & Casualty/Risk & Benefits Management Edition, November 14, 2003. Copyright 2003 by The National Underwriter Company in the serial publication. All rights reserved.Copyright in this article as an independent work may be held by the author.