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A Test Bed to Examine Helmet Fit and Retention and Biomechanical Measures of Head and Neck Injury in Simulated Impact
Published on: September 21, 2017
Rear-impact neck protection devices for adult wheelchair users
Ciaran K Simms1, Brian Madden, David Fitzpatrick
1Trinity Centre for Bioengineering, Trinity College, College Green, Dublin 2, Ireland. csimms@tcd.ie
Journal of Rehabilitation Research and Development
|November 3, 2009
Summary
Rear impacts pose a significant risk to wheelchair users, with neck injury risk substantially reduced by wheelchair head restraints. Minimizing the head-to-restraint gap is crucial for effective whiplash protection.
Area of Science:
- Biomechanics
- Occupant Safety
- Rehabilitation Engineering
Background:
- Wheelchair users often remain seated during vehicle transit, facing risks from various impact types.
- Existing safety research for wheelchair users predominantly addresses frontal impacts, leaving rear-impact protection understudied.
- Rear-impact injuries, though less severe, incur high treatment costs and significant patient burden, particularly whiplash for adult wheelchair users.
Purpose of the Study:
- To evaluate the effectiveness of wheelchair head restraints in mitigating neck injury risk during rear-impact collisions.
- To assess the impact of head restraint design, specifically the head-to-cushion gap, on injury metrics.
Main Methods:
- 10 g (16 km/h) rear-impact sled tests were conducted using the Biofidelic Rear Impact Dummy II (BioRID-II).
- Tests involved a rigid wheelchair with and without head restraints (a prototype and a commercial model).
- Neck injury risk was evaluated using the Neck Injury Criterion (NIC) and Nkm criterion, with injury scores compared against proposed thresholds.
Main Results:
- Without head restraints, BioRID-II exhibited neck injury risk substantially above proposed thresholds (NIC: 34-37, Nkm: 1.16).
- Both tested head restraints significantly reduced injury scores when the gap was minimized (NIC: 18-24, Nkm: 0.30-0.35).
- Preliminary findings suggest a minimal horizontal gap between the head and head restraint cushion is optimal.
Conclusions:
- Wheelchair head restraints demonstrate significant potential in reducing neck injury risk for wheelchair users during rear impacts.
- Optimizing the head restraint design, particularly minimizing the gap, is critical for enhancing occupant safety.
- Further research with larger sample sizes is recommended to confirm these trends and refine head restraint designs.
