Ligament Stretching During Whiplash Movement
This study examined the effectiveness of a new sensor that measures ligament length during motion testing. The researchers placed this new sensor on a cadaveric spine, and measured the range of motion of the right C6-C7 capsular ligament during flexibility tests and simulated whiplash.
"The maximum C6-C7 capsular ligament elongation (7.2 mm) during the specimen flexibility testing occurred in the left lateral bending...During whiplash simulations, the maximum recorded ligament lengths were 7.2, 7.4, 7.8, and 8.2 mm, respectively, for 3, 4, 8, 10 g accelerations of the sled. These lengths exceeded the earlier-established ligament elongation during the flexibility testing."
While more studies must be done in this area, these findings indicate that relatively minor collisions may result in excessive loading to the spinal ligaments. (A collision of just 6 mph can result in G forces of 6.5g.) From the preliminary findings of this current study, this low speed collision may result in ligament stretch.
Cholewicki J, Panjabi MM, Nibu K, Macius ME. Spinal ligament transducer based on a hall effect sensor. Journal of Biomechanics 1997;30(3):291-293.