Why back pain in rear impact RTA

BACK PAIN AS A PART OF WHIPLASH DISORDERS

Back pain is often complained by claimants as an additional concern to cervical spine in association with road traffic accidents. The literature illustrates the incidence of lower back pain associated with cervical acceleration/deceleration (CAD) injury vary from a low of 25-57%

Studies of occupant kinematics demonstrate very complex lumbar biomechanics during CAD, which includes a likely flattening of the lumbar spine, followed by compression, ramping, and then tension. The combination of neck pain and low back pain following whiplash trauma also seems to be common.

 Mechanism

As such the exact mechanism of lower back injury in rear impact collisions, although not entirely clear, is probably multifactorial and includes position of the occupant in vehicle and the type of restraint system the use or non-use of seat belts and shoulder harness, stiffness of the seat back, inclination of the seat back.

There is a number of prosed mechanisms that may account for the concern with the commonest being the suggestion of straightening of the lumbar spine with axial loading. Fig. 1 illustrate that the forces on the lumbar spine however do not reach the same magnitude as those noted in the cervical spine.

Yang et al  Volunteer subject studies in low speed rear impacts have shown that significant lumbar spine injuries are unlikely in such collisions. Anthropomorphic test devices (ATD) used in low to medium speed rear impact simulations have similarly revealed an unlikely mechanism to cause lumbar spine injuries.