Project: Lower Back Injuries Resulting from Road Accidents

Reference: S202J/VF

Last update: 02/09/2003 13:54:18


This project was jointly funded with Road Safety Division and was carried out by three contractors: the Department of Orthopaedic Surgery, University of Manchester, the DTLR Vehicle Inspectorate and TRL Limited. The aim of the project was to study the long-term disabling effects of injuries to the lumbar region of the back, which have been sustained in road traffic accidents, and to attempt to relate the severity and duration of these injuries to factors such as vehicle damage, estimated collision speed, impact type, head restraint fitting/adjustment and seat type and adjustment. Information on such causative factors could possibly enable effective countermeasures against these injuries to be developed.


Although the main thrust of the study was towards lower back injuries, people who had suffered whiplash injuries, with or without concomitant lower back injury, were also included in order to follow up on a previous project which was primarily intended to examine whiplash injury. It was during the course of this previous project (S093A/VF) that the significance and extent of the problem of lumbar injuries was first recognised. A brief analysis of the Co-operative Crash Injury Study's (CCIS) databases was also carried out, to obtain a broader view of lumbar strain injuries and to place them in the context of other spinal injuries resulting from road traffic accidents. Results from these databases indicated that women were more at risk than men of incurring strain injury in all regions of the spine. In addition, rear impact carried a higher risk of spinal strain injury (again, in all regions), but frontal impacts produced higher actual numbers of injuries. Finally, many of the spinal strain injuries were described as non-contact injuries, or as being due to indirect loading, indicating the difficulty the crash investigators had in finding occupant contacts within the vehicle to correlate with these injuries.


TRL Limited
Crowthorne House, Nine Mile Ride, Wokingham, Berkshire, RG40 3GA
+44 (0)1344 773131

Contract details

Cost to the Department: £238,000.00

Actual start date: 01 August 1996

Actual completion date: 28 February 2001


PR/SE/259/01. A study of lower back strain injuries resulting from road accidents
Author: TRL Ltd
Publication date: 01/06/2001
Source: Contact
More information:

A Study of Lower Back Strain Injuries Resulting from Road Accidents
Author: TRL Ltd
Publication date: 01/06/2002
Source: Contact

Lower Back Injuries Resulting From Road Accidents: third Interim Progress Report
Author: TRL Ltd
Publication date: 01/06/1999
Source: Contact

Summary of results

  1. Approximately one third of subjects in the present study still had some degree of disability two years after their accidents. A previous history of back problems was very significantly correlated with long-term disability, although in a number of cases, these previous back problems had themselves been caused by road accidents. Women suffered higher disability than men. Older people recovered more slowly, although their initial disability tended to be lower than that of younger people.

    However, trends for back length in relation to the height of the seat backrest were contradictory and inconclusive. Neither weight, neck length, neck circumference nor body mass index (obesity) showed any conclusive correlation with disability. Being braced for the impending impact was detrimental for those with prior back problems, while there were indications that being involved in a right side impact was beneficial.

    Where a head restraint was present, results indicated that it should either be hard or, if soft, be thickly padded. There was some indication that greater horizontal distance between head and restraint may be detrimental. Results for vertical head restraint adjustment were inconclusive. There were indications that hinged seat backrests may be beneficial, but only for those without prior back problems. Hard structure at the base of the backrest, which was close enough to the surface to be detected by the vehicle examiners, was detrimental for women and for those with prior back problems. Restriction of this sample to particular makes and models of vehicles was not found to clarify which factors were significantly related to injury risk, as the sample size became too small.