Transportation Safety for Wheelchair Occupants - Part 1

This is the first part of a 90 slide lecture.

Go ahead to Part 2 (the middle 30 slides)

Go ahead to Part 3 (the last 30 slides)


A slide lecture created by: Linda van Roosmalen, PhD & DongRan Ha, PhD

First slide in the presentation… Transportation Safety for Wheelchair Occupants


Wheelchair Transportation Safety

slide 2: Wheelchair Transportation Safety

Slide text:

  • 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

slide 3: Impact Direction

Slide text:

Direction of Impact

  • Front = Cars/Vans 48.3% and School Buses 55.9%
  • Side=Cars/Vans 28.5% and School Buses 14.7%
  • Rear=Cars/Vans 3.3% and School Buses 0%
  • Other=Cars/Vans 19.9% and School Buses 29.4%

Graphic description:

The table shows that frontal impact has the highest accident rate when compared to side and rear vehicle impact.


Impact Severity

slide 4: Imact Severity

Slide text:

  • Injury Risk:
    • Proportional to velocity change (=acceleration)
  • Occupant Restraints protect the occupant by:
    • Increasing the time over which the velocity changes
    • Therefore reducing the acceleration loads

Safety Guidelines

slide 5: safety guidelines

Slide text:

  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

Wheelchair Securement Systems

slide 6: Wheelchair securement systems

Slide text:

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

Strap type tie-down system

slide 7: strap type tie-down system

Slide text:

  1. Advantages
  • Four securement points (improves crash response and stability)
  • Adaptable to most wheelchair types
  • No additional wheelchair hardware require
  • Withstands crash forces

Graphic description:

Picture of a wheelchair that is tied down to the vehicle floor with 4 belts. 2 belts on the left and right front of the wheelchair and two belts on the left and right rear of the wheelchair. Aluminum tracks can be used to anchor the belts to the vehicle floor.


Strap type tie-down system

slide 8: strap type tie-down system

Slide text:

  1. 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

Docking Systems

slide 9: Docking Systems

Graphic description:

Picture of an EZ Lock system, that can automatically secure a wheelchair to the vehicle floor. For this to work, the wheelchair needs to be equipped with a bolt underneath the wheelchair. This bolt is caught by the docking system when the wheelchair rides over it.


Docking System

    slide10: Docking Systems

    Slide text:

    1. Advantages
    • Quick securement times
    • Independent securement
    • Eliminates need for human judgment of securement point location
    • Minimizes error
    • Withstands crash forces

    Graphic description:

    Pictures show the EZ-Lock docking system and a wheelchair that is equipped with a interface that fits in a docking type securement system.


    Docking System

    slide11:Docking Systems

    Slide text:

    1. Advantages
    • Require additional wheelchair hardware
    • Difficulty in adapting add-on hardware to all wheelchair types
    • Add on hardware adds weight
    • Add-on hardware may affect ground clearance and/or overall wheelchair length
    • Fewer securement points (less stability and control of crash response)

    Wheel Clamps

    slide12:wheel clamps

    Graphic description:

    Pictures show the side ways installed wheel clamp system, which is not recommended, because the wheel can come detached from the wheelchair during impact and the occupant is sideways facing, which is a non safe position during frontal impact.


    Wheel Clamps

    slide13: wheel clamps

    Slide text:

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

    Rearward Facing Compartment

    slide14: Rearward facing compartment

    Graphic description:

    Pictures of a flip up seat and ‘ironing board’ that function as a rearward facing back stop for wheelchair users traveling in low g (low speed) vehicles such as public buses.

    Rearward Facing Compartment

    slide15: Rearward facing compartment

    Slide text:

    • Easy to use
    • Quick
    • Non-constraining
    • Independent use

    BUT….

    Graphic description:

    Pictures of an ‘ironing board’ that functions as a rearward facing back stop for wheelchair users traveling in low g (low speed) vehicles such as public buses.


    Rearward Facing Compartment

    slide16: Rearward facing compartment

    Slide text:

    Only for the following situations:

    1. Large vehicles with relatively low accelerations
    2. Fixed route transit
    3. Vehicles with low Injury incidence

    Research is needed to evaluate safety of this type wheelchair ‘compartment’ during emergency driving (braking, turning, accelerating)


    General Securement Issues

    slide17: General securement issues

    Slide text:

    • Heavier WCs generate larger forces
    • Systems securing heavier WCs must withstand greater forces
    • To accommodate heavy WCs (>275 lb):
      • 4 rear tie-downs instead of 2

    Rear tie-down loads during frontal impact:

    • 6000-7000 lbs for:
      • Power wheelchair (180 lbs)
      • 50th percentile male user (168 lbs)

    Wheelchair Safety Standards

    slide18: Wheelchair safety standards

    Slide text:

    • National Standard: ANSI/RESNA WC19
    • International Standard: ISO 7176-19
      • Wheeled mobility devices for use in Motor Vehicles
      • Test requirements: 20g/30mph frontal impact test
      • Wheelchair integrated pelvic belt (as of 2002)

    Graphic description:

    ANSI/RESNA WC/19 is U.S. standard, and at the International level, ISO 7176-Part 19: Wheeled Mobility Devices for Use in Motor Vehicles is in process of developing as a standard. They both requires that a complete, unused commercial or prototype wheelchairs to be sled impact tested using a 20g/48kph (30mph) frontal crash pulse.

    Difference is that , ISO 7176-part 19 is for wheelchairs designed for adult occupants whose mass greater than 36 kg and ANSI/RESNA WC/19 is for wheelchairs designed for both adults and children with a body mass of greater than or equal to 22 kg (48 lb).


    Wheelchair Safety Standards

    slide19: Wheelchair safety standards

    Slide text:

    • ISO 10542/SAE J2249
      • Wheelchair Tie-down and Occupant Restraint Systems (WTORS)
        • 30mph/20g Impact Test
      • Requirements for:
        • 4-point strap type tie-down systems
        • Docking systems
        • Clamping systems
        • Systems for special wheelchairs

    Graphic description:

    ANSI/RESNA WC/19 is U.S. standard, and at the International level, ISO 7176-Part 19: Wheeled Mobility Devices for Use in Motor Vehicles is in process of developing as a standard. They both requires that a complete, unused commercial or prototype wheelchairs to be sled impact tested using a 20g/48kph (30mph) frontal crash pulse.

    Difference is that , ISO 7176-part 19 is for wheelchairs designed for adult occupants whose mass greater than 36 kg and ANSI/RESNA WC/19 is for wheelchairs designed for both adults and children with a body mass of greater than or equal to 22 kg (48 lb)


    Securement Guidelines

    slide20: Securement guidelines

    Slide text:

    • Securement point location on vehicle
    • Securement point location on WC
      • rear tie-down close to WC center of gravity
      • Securement close to ‘bulk of WC mass’
      • Location too low: forward WC rotation
      • Location too high: rearward WC rotation

    Graphic description:

    Pictures showing the recommended tiedown angles for a 4-point belt type securement system.


    Web Resources

    slide21: Web resources

    Slide text:

    • www.rercwts.pitt.edu
    • Standards info: www.wheelchairstandards.pitt.edu
      • http://www.wheelchairstandards.pitt.edu/ANSIRES/
      • SOWHAT/SOWHATindex.html#anchor13088715
      • http://www.wheelchairstandards.pitt.edu/ISO/ISOindex.html
      • http://www.wheelchairstandards.pitt.edu/SAE/
      • unitindexSAE.html#anchorSAEJ2249

    Transit Options on Wheelchairs

    slide 22: Transit options on wheelchair

    Slide text:

    • Snug Seat
    • Quickie 900
    • Orthokinetics
    • Tumble Forms (Carrie Rover)
    • Physio ERP Alvema
    • Kid-E-Plus

    Graphic description

    Pictures showing the transit option on wheelchairs. 4 D-shaped rings, 2 on the front and 2 on the back of the wheelchair seating system, or frame.


    Transit Options on Wheelchairs

    slide 23: Transit options on wheelchairs

    Graphic description:

    Pictures showing the transit option on wheelchairs. 4 D-shaped rings, 2 on the front and 2 on the back of the wheelchair seating system, or frame.

    Occupant Restraints Reduce Injury Risk By….

    slide24: Occupant restraints reduce inury risk by...

    Slide text:

    • Increasing the time over which the occupant comes to a stop
      • Decreasing deceleration or “G’s”
    • Decreasing occupant forward travel
      • Reduces risk of impact with vehicle surface therefore reducing risk of injury!

    Upper torso and pelvic belt loading: 3000 lbs.


    Types of Occupant Restraints

    slide 25: Types of occupant restraints

    Slide text:

    • 3 point restraint system:
      • Pelvic restraint (lap belt)
      • Upper torso restraint (shoulder belt)
    • Harness type system
      • 4-point restraint system

    Belts fixed to wheelchairs are generally for positioning and NOT for safety

    Graphic description:

    • Integrated Restraint
      • In series with W/C tiedown or anchored to the wheelchair
      • Load capacity of W/C tiedown must carry W/C and occupant load
    • Independent Restraint
      • In parallel with W/C tiedown
      • Anchor to floor separate from W/C tiedown
      • Less load on W/C tiedown

    3-point Occupant Restraint System

    slide 26: 3-point occupant restraint system

    Graphic description:

    Pictures showing the 3 point occupant restraint system properly positioned over the bony parts of the body (pelvis, sternum).


    3-point Occupant Restraint System

    slide 27: 3-point occupant restraint system

    Graphic description:

    Picture showing an integrated pelvic belt (used when transporting a light child in a heavy power chair). Picture showing an independent pelvic belt (used when transporting a lighter chair with an occupant). Wheelchair is independently secured from the occupant.


    Harness Type Restraint

    slide 28: Harnes tyoe restraint

    Graphic description:

    Examples of safe occupant restraint systems for small children.


    Restraint Installation Issues

    slide 29: Restraint installation issues

    Slide text:

    • 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

    Graphic description:

    Picture that shows poor belt fit (belt touching the neck of the child) when used for a 6-year old child seated in a wheelchair.


    SAE J2249 Installation Guidelines

    slide 30: SAE J2249 Installation Guidelines

    Graphic description:

    Pictures showing the recommended upper torso anchor point location, to provide optimal belt fit for a 50th percentile male wheelchair occupant.

    This is the end of the first part of a 90 slide lecture.

    Go ahead to Part 2 of the slide lecture (the second 30 slides)

    Go ahead to Part 3 of the slide lecture (the last 30 slides)

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