ObjectivesTo outline research underway at the Injury Biomechanics Laboratory at the University of British Columbia and illustrate the importance of a collaborative relationship between biomechanical engineers and provincial and national injury prevention organizations such as the British Columbia Injury Research and Prevention Unit.

+Departments of Mechanical Engineering and Orthopaedics and *Department of Paediatrics, University of British Columbia, #BC Injury Research and Prevention Unit, Vancouver, BC

Contact: Shelina Babul, PhD, Tel: (604) 875-3682, Fax: (604) 875-3569, Email: sbabul@cw.bc.ca

INJURY BIOMECHANICS AS A MEANS TO PREVENT INJURIES IN CANADA

INTRODUCTION

Injury Biomechanics is centrally involved in understanding the mechanisms of human injury. This information is used to prevent injuries or advance medical treatments. Examples of injury prevention devices that biomechanical engineers have been centrally involved in include the development and advancement of seat belts, airbags and helmets.

Peter A. Cripton+ and Shelina Babul*#

Acknowledgements:

Financial support in the form of research grants from GM Canada (PACE), and Natural Sciences and

Engineering Research Council of Canada (NSERC), and the Rick Hansen Man in Motion Fund, are gratefully

acknowledged. .

References:

1. Boak J.C., Lau C., Bellezza A., Saari A., Cripton P.A., Ocular Injury Tolerance to Projectile Impacts During Motor Vehicle Collisions. Proceedings of the 2005 Annual Meeting of the Association for Research in Vision and Ophthalmology. May 1-5, 2005, Fort Lauderdale, FL, USA

2. Saari A, Morley P, Cripton PA, Spinal cord deformation during burst fractures of the cervical spine in the presence of physiologic preload. Proceedings of the 2005 Summer Bioengineering Conference of the American Society of Mechanical Engineers, June 22-26, Vail, CO, USA

3. Louman-Gardiner K, Mulpuri K, Perdios A, Tredwell S, Cripton PA, Pediatric chance fractures and associated neurological injury in British Columbia: recommendations for injury prevention, Proceedings of the International Collaboration on Repair Discoveries (ICORD) Annual Research Meeting, October 17, 2005

4. Duma SM, Crandall JR. J Trauma 2000;48:786-9.

5. Potts AM, Distler JA. American Journal of Ophthalmology 1985;100:183-7.

6. Rajabali F et al. Unintentional injuries in BC: trends and patterns among children and youth 2005, BCIRPU Report

7. Christensen L, Reid L, Booster seat law in BC-at what compromise? 2002 ICBC& BCAA presentation

Theme 1: Prevention of Eye Injuries 1

Motivation: Injuries to the spinal cord (Figure 3) result in loss of function below the level of the injury with catastrophic consequences from quality of life, health care utilization, and financial perspectives. Method: Drop Tower Experiments (Figure 4) Conclusion: Prevention of Spinal Cord Injuries

This technique will be used to evaluate and develop novel devices to prevent spinal injuries in automotive and sports environments.

Figure 2 – Corneal abrasion and penetration summary graph: This graph summarizes data made available to the authors, Potts and Distler5 and Duma and Crandall.4 Smaller and sharper objects penetrate the globe at momentums that are several magnitudes lower than those necessary with 10 mm diameter rigid spheres.

Projectiles

Figure 1 – Schematic of eye tolerance experiment.

Motivation: Ocular injury tolerance data can aid automotive design by recommending limits on the allowable speed, mass, and shape of projectiles associated with airbag deployment or vehicle damage during motor vehicle collisions. Method: Literature search

STAPP Car Crash Conference Proceedings and Pubmed Medline

Results: Eye Injury Tolerance Projectiles of various size, shape and mass (Figure 1)

Corneal Injury tolerance data (Figure 2)

Theme 2: Prevention of Spinal Cord Injuries 2

Theme 3: Improving Child Restraint Performance 3

Conclusion: Prevention of Eye Injuries Automotive manufacturers can use the assembled

data to optimize the design of airbags such that projectiles produced during airbag deployments or collisions do not injure occupants’ eyes.

Figure 3 - C-spine fractures occur at speeds over 3m/s i.e. diving into shallow water or in automotive rollovers.

Figure 4 - Drop tower used to induce burst fracture injuries

Motivation: Motor vehicle traffic is the leading cause of death in BC for the ages 0 to 14 years.6 High rates of child restraint misuse have been reported in BC7 (Figure 5). Method: Investigations of specific MVCs

Engineering, epidemiological and medical Investigations of BC injuries to children associated with specific motor vehicle collisions.

Conclusion: Improving Child Restraint Performance This information will be used to educate the public, guide policy

decisions and to identify performance improvements to child restraints that can be accomplished through engineering redesign.

Figure 5 – Six-year-old occupant simulation. The yellow line indicates head motion. (Source: Partners for child passenger safety). This is a common misuse when the shoulder belt doesn’t fit properly.

GENERAL CONCLUSION

Injury prevention is a complex multidisciplinary field. Many injury prevention research topics require effective interdisciplinary collaboration between physicians, epidemiologists, engineers, and others.

• Injury Biomechanics is centrally involved in understanding the mechanisms of human injury. This information is used to prevent injuries or advance medical treatments. Examples of injury prevention devices that biomechanical engineers have been centrally involved in include the development and advancement of seat belts, airbags and helmets. In the realm of injury treatment biomechanical engineers have contributed to novel treatments for spinal cord injury by helping to improve the concordance between the injuries suffered by human patients and those used to develop new treatments in rodent models.

• The objective of this presentation will be to outline research underway at the Injury Biomechanics Laboratory at the University of British Columbia. The important collaborative relationship between biomechanical engineers and provincial and national injury prevention organizations such as the British Columbia Injury Prevention Unit will be highlighted.

• Theme 1 - Eye Injury: Injury due to small projectiles contacting the eye at high velocity can be devastating because of potential loss of vision. Ocular injury tolerance data can aid automotive design by recommending limits on the allowable speed, mass, or shape of projectiles associated with airbag deployment or vehicle damage during motor vehicle collisions. It was determined that little quantitative information is known about the tolerance for eye injury for projectiles of the size, shape, or mass characteristic of automobile collisions. In this research, biomechanical engineers can design and perform experiments to quantitatively determine the tolerance of the eye to injury using cadaveric eyes and simulated projectiles propelled by an air cannon.

• Theme 2 – Spinal Cord Injury: Spinal cord injury is a devastating injury with enormous associated societal and financial burdens. The objective of this research is to quantitatively determine the mechanical deformation that the spinal cord undergoes during various kinds of common spinal injuries such as diving injuries or injuries associated with automotive rollovers. This is done using cadaveric spinal segments and a sensor placed in the spinal canal which can be used to measure spinal cord deformation during spinal injury.

• Collaboration with physicians and epidemiologists as well as researchers with other expertise is essential in these fields as it provides a quantitative understanding of the importance of the research question in the Canadian context (epidemiology) as well as an understanding of the clinical presentation and treatment of affected individuals.