Transportation Safety for Wheelchair Occupants Linda van Roosmalen, PhD Douglas Hobson, PhD Department of Rehabilitation Science and Technology University of Pittsburgh Funding: National Institute on Disability and Rehabilitation Research March 2004 ISS-Instructional Course

Application to practice Wheelchair transit and associated risks Methods to prevent occupant injury Safety guidelines and Standards Resources

Wheelchair Transportation Safety 1.6 million wheelchair users Access to motor-vehicle transportation is the key to functioning in society ADA prohibits discrimination in public transportation services 2001 New Freedom initiative calls for integration of disabled persons into workforce and community - “transportation” critical factor in meeting this priority 82% of wheelchair users indicate difficulty with using public transportation Wheelchair users have 10% higher unemployment rate

Impact Direction Direction of Impact: Cars/Vans:School Buses: Front 48.3% 55.9% Side 28.5%14.7% Rear 3.3% 0% Other19.9% 29.4% NHTSA, FARS Database

Impact Severity Injury Risk: –Proportional to velocity change –“Loading = velocity * body weight” Occupant Restraints protect by: –Prevent occupant ejection from vehicle –Prevent excessive occupant motion –Reduce occupant loading –Increasing time of energy exposure

Safety Guidelines 1.Secure the wheelchair 2.Restrain the occupant 3.Remove loose accessories from wheelchair 4.Remove parts that can injure occupant during an impact –Lap trays, loose objects, postural supports, communication devices, neck rings

Sled Impact Testing Frontal 30mph 20g

Safety System #1 Secure the Wheelchair to the Vehicle

Wheelchair Securement Systems –Four point strap type tie-downs –Docking systems –Other: wheel-clamps, hybrids –Rearward facing compartments (in large buses)

Strap type tie-down system Advantages –Four securement points (improves crash response and stability) –Adaptable to most wheelchair types –No additional wheelchair hardware required –Withstands crash forces IMMI-Westfield (IN)

Strap type tie-down system Disadvantages –Invasion of personal space –Lengthy securement times –Requires operator/attendant for securement –Tiedowns easily misplaced or soiled –Lack of defined wheelchair securement points –Requires operator training when securing a variety of wheelchairs

Easy Accessible Securement Points NO!!!

Easy Accessible Securement Points YES!!!

Docking Systems Advantages –Quick securement times –Independent securement –Eliminates need for human judgment of securement point location –Minimizes error –Withstands crash forces EZ-Lock (Baton Rouge, LA)

Docking Systems Disadvantages –Requires add-on hardware –Requires adaptations to all wheelchair types –Hardware adds weight and length –Hardware affects ground clearance –Fewer securement points (less stability and control of crash response)

Wheel Clamps

Disadvantages –Unable to safely withstand crash forces –Not compatible with all wheel types –Requires attendant for securement Advantages –Fairly quick securement –Less invasive

Passive Restraint: Containment Wheelchair is positioned rearward facing in the vehicle

Passive Restraint: Containment Easy to use Quick Non-constraining Independent use HOWEVER…. For use in ’low-g’ vehicles only –More research is needed to evaluate safety during emergency driving situations (Van Hool, Belgium)

Safety System #2 Restrain the Occupant –To vehicle and/or wheelchair Lap belts mounted to wheelchair frames are generally for positioning purposes and NOT for safety during transit!!!

Occupant Restraints Reduce Risk of Injury Prevent occupant ejection Increasing time over which the occupant comes to a stop –Decreasing deceleration or “G-loads” –Higher weight means higher loads! Decrease occupant forward travel –Reduce risk of occupant impact with vehicle interior

Sled Impact Testing without use of Occupant Restraints Frontal 30mph 20g

Sled Impact Testing with proper Occupant Restraints Frontal 30mph 20g

3-Point Occupant Restraint Upper torso belt (shoulder belt) Pelvic belt (lap belt)

Gorilla Car Seat Carrie Bus Seat Snug Seat Car Bed Harness Type Restraint EZ-On Vest

Occupant Restraint Safety Improperly positioned pelvic belt: –Abdominal injury due to ‘submarining’ –Lumbar vertebra injury in frontal crashes Improperly positioned shoulder belt: –Excessive head excursions –Secondary impact with vehicle surfaces –Injuries to vital thoracic cavity organs Adomeit & Heger, 1975; Leung et al., 1985

Occupant Restraint Problems Appropriate belt fit related to: –Shoulder belt anchor point –Pelvic belt anchor point –Wheelchair and occupant size –Location of wheelchair in securement zone –Available clearance for belt placement

Common Problems Shoulder belt slip off user’s shoulder –Due to shallow angle of torso belt Shoulder belt rubs against user’s neck –Discomfort, –Resistance to using belt –Decreased upper torso restraint Anchoring upper torso restraint below shoulder may result in downward loading of torso and spine

Occupant Restraint “Best Practices” Use both pelvic and shoulder belt to restrain the occupant Lead restraints over bony anatomy –Shoulder restraint over the Sternum –Pelvic restraint over the (pelvis) Iliac Crests Avoid loading soft tissues (abdomen) Remove belt slack Use a retractor to reduce upper torso belt slack Restraint pre-tensioner reduces belt loading

Wheel clamps Sideward facing position

4-Point Tiedown Systems Twisted BeltsBelt interferes with tires

Occupant Restraints & Postural Supports No use of shoulder belts Pelvic belt over armrests

Ongoing Research Automated Wheelchair Securement –Universal docking Customized Occupant Restraints –Wheelchair integrated –Consumer friendly

Safety System #3 Support the Occupant –Wheelchair seating system –Wheelchair frame –Wheelchair components