Backset and cervical retraction capacity among occupants in a modern car
Journal article, 2007

OBJECTIVES: The horizontal distance between the back of the head and the frontal of the head restraint (backset) and rearward head movement relative to the torso (cervical retraction) were studied in different occupant postures and positions in a modern car. METHODS: A stratified randomized population of 154 test subjects was studied in a Volvo V70 year model 2003 car, in driver, front passenger, and rear passenger position. In each position, the subjects adopted (i) a self-selected posture, (ii) a sagging posture, and (iii) an erect posture. Cervical retraction, backset, and vertical distance from the top of the head restraint to the occipital protuberance in the back of the head of the test subject were measured. These data were analyzed using repeated measures ANOVA and linear regression analysis with a significance level set to p < 0.05. RESULTS: In the self-selected posture, the average backset was 61 mm for drivers, 29 mm for front passengers, and 103 mm for rear passengers (p < 0.001). Women had lower mean backset (40 mm) than men (81 mm), particularly in the self-selected driving position. Backset was larger and cervical retraction capacity lower in the sagging posture than in the self-selected posture for occupants in all three occupant positions. Rear passengers had the largest backset values. Backset values decreased with increased age. The average cervical retraction capacity in self-selected posture was 35 mm for drivers, 30 mm for front passengers, and 33 mm for rear passengers (p < 0.001). CONCLUSIONS: Future design of rear-end impact protection may take these study results into account when trying to reduce backset before impact. Our results might be used for future development and use of BioRID manikins and rear-end tests in consumer rating test programs such as Euro-NCAP.

Seated posture

Car seat

Whiplash injury

Cervical motion

Head restraint

Neck motion

Author

Bertil Jonsson

University Hospital of Umeå

Umeå University

H Stenlund

Umeå University

Mats Svensson

Chalmers, Applied Mechanics

Ulf Björnstig

Umeå University

Traffic Injury Prevention

1538-9588 (ISSN) 1538-957X (eISSN)

Vol. 8 1 87-93

Subject Categories

Physiology

Vehicle Engineering

DOI

10.1080/15389580600911010

More information

Latest update

11/17/2021