Mechanisms of brain injury related to mathematical modelling and epidemiological data

Willinger, R.; Ryan, G. A.; McLean, A. J.; Kopp, C. M.

Measurements of the impulse frequency response of head impact points on the exterior and the interior of a car were used to calculate the modal mass and stiffness for each point. These points were then arranged in an hierarchy of increasing stiffness and grouped into three classes. Thirty two head impact cases (13 pedestrian, 4 car occupants and 15 fall victims) in which the distribution of injury to the brain had been recorded in detail were grouped according to the stiffness of the object struck and by the location of the impact on the head. The distribution of the brain injury lesions in the anterior, middle and posterior regions of the brain were determined for each class of stiffness (soft, medium or hard) and location of impact (occipital or lateral). Distinctive patterns of brain injury distribution were noted for each class of stiffness and each location of impact. Three probable mechanisms of brain injury were distinguished. They were: relative motion between the brain and the skull, local bone deformation and intra-cerebral strains. Each mechanism was related to a range of stiffness and natural frequency of the structure impacted. Hence these theories of brain injury mechanisms are consistent with observed epidemiological data and with conclusions drawn from mathematical modelling.

Year

Entry

1991

Willinger R, Kopp CM, Cesari D. Cerebral motion and head tolerance. In: 35th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 7, 1991; Toronto, Canada.387-404.

1991

Willinger R, Césari D, Kopp CM. Brain tolerance in the frequency field. In: Proceedings of the 13th International Technical Conference on Experimental Safety Vehicles (ESV). November 4-7, 1991; Paris, France.940-947.

1991

Manavis J, Blumbergs PC, Scott G, North JB, Simpson DA, Ryan GA, McLean AJ. Brain injury patterns in falls causing death. In: Proceedings of the 1991 International IRCOBI Conference on the Biomechanics of Impact. September 11-13, 1991; Berlin, Germany.77-88.

1990

McLean AJ, Blumbergs PC, Kloeden CN, Palmer GJ, Ryan GA. The relative motion concept of brain injury. In: Proceedings of the 1990 International IRCOBI Conference on the Biomechanics of Impact. September 12-14, 1990; Lyon, France.181-189.

1989

Ryan GA, McLean AJ, Vilenius ATS, Kloeden CN, Simpson DA, Blumbergs PC. Head impacts and brain injury in fatally injured pedestrians. In: Proceedings of the 1989 International IRCOBI Conference on the Biomechanics of Impact. September 13-15, 1989; Stockholm, Sweden.27-37.