Jennifer Walsh, Ciaran Simms
Trinity Centre for Bioengineering, Trinity College, Dublin
David FitzPatrick
School of Electronic and Mechanical Engineering, University College Dublin
John Tiernan
Eastern Region Postural Management, Enable Ireland

During transportation, many wheelchair occupants remain in their wheelchair which is secured to the vehicle floor using tie downs, and the occupant is restrained in the wheelchair using a vehicle mounted belt system.

Crash safety techniques have benefited greatly from experimental and numerical tests using crash test dummies. However, in order to adequately design for wheelchair users these crash test dummies must be adapted to reflect postural deformities frequently present in wheelchair users. A particular case of this is the neuromuscular scoliosis which accompanies cerebral palsy.

This paper reports on numerical modelling of this form of scoliosis by the introduction of a lateral curvature to the spinal column to reflect the deformed scoliotic spine. The altered muscle tone associated with cerebral palsy will be introduced, based on findings by Stackhouse et al1 who investigated muscle contraction and the corresponding force in children with and without cerebral palsy.

The focus of this project is rear impact. Validation of the baseline numerical model was achieved by comparison with experimental rear impact crash tests. Results of this validation are presented.

The computational model of the wheelchair occupant was then altered to reflect a person with scoliosis and the response of this occupant was investigated. A qualitative increase in predicted injury was found when compared to a non-scoliotic occupant. This work will provide information to determine the requirements to improve crash safety for wheelchair occupants with scoliosis.