J Manipulative Physiol Ther 1998 (Nov); 21 (1): 629–639
Background: There is a controversy regarding
likelihood of injuries sustained when one car strikes another at
a relatively low speed with little or no vehicle damage.
Plaintiffs often claim injuries while defendants counterclaim
that injuries could not have occurred with such a relatively
Objective: To review the dynamics of low speed rear-end
collisions resulting in little or no visible damage and to see if
occupant injury can occur; also, to discuss diagnostic and
treatment that may be helpful to the clinical
Data Selection: A medline search of low speed
rear-end was conducted. Other articles and studies were reviewed
that discuss low speed rear-end collisions and factors impacting
the neuromusculoskeletal system relevant to clinical
practitioners. Articles included were: human low speed rear-end
tests, lab tests on cadavers, automotive engineering papers, and
peer reviewed journal articles on whiplash. A few live animal and
simulation studies were considered for the background of possible
injury mechanism and vehicular deformation. Excluded were non
rear-end collision and single case reports.
Data synthesis: The data was studied to find a
relationship between the resultant vehicle dynamics with occupant
movement, biologic mechanisms of injury and the neurological
mechanisms causing complaints. Data was also studied to
investigate objective findings supporting subjective complaints.
Conclusion: In low impact collisions, there are
usually no skid marks, minor or no visible damage to the vehicle.
There is a lack of relationship between occupant injury vehicle
speed and/or damage. There does not appear to be an absolute
speed or damage to a vehicle for a person to experience injury.
Crash tests indicate a change of vehicle velocity of 4km/h (2.5
mph) may produce occupant symptoms. Vehicle damage may not occur
until 14-15km/h (8.7 mph). Occupant soft tissue and joint
injuries resulting from low speed vehicle collisions respond
positively to afferent stimulation of mechanoreceptors. The
diagnosis of the occupant injuries is reliant upon standard
orthopedic neurological testing, the autonomic concomitant signs
and qualitative sensory testing.
Key Indexing Terms: Cervical Spine; Whiplash Injury; Low