Usability and Satisfaction of Wheelchair Occupant Restraint Systems used During Motor Vehicle Transport
A Preliminary Evaluation

by Linda van Roosmalen PhD
Gina E Bertocci PhD
Douglas A Hobson PhD
Patricia Karg MS

Slide 1
Usability and Satisfaction of Wheelchair Occupant Restraint Systems used During Motor Vehicle Transport
A Preliminary Evaluation

by Linda van Roosmalen PhD
Gina E Bertocci PhD
Douglas A Hobson PhD
Patricia Karg MS

Slide 2
Introduction

13.2 Million Americans have mobility difficulties when outside their homes

1.4 Million full-time WMD users (NIDRR, 1993)

2,494 injuries or deaths among WMD users due to improper securement

65% involves wheelchairs in vans (NHTSA-Neiss, 1997)

Type, size and mass of vehicle effect fatality rate of wheelchair users

Most injuries, due to abrupt vehicle maneuvers, can be prevented (Shaw, 2000)

Slide 3
Background

50% of wheelchair users in privately owned vehicles use wheelchair occupant restraints (Sprigle, Morris, Nowacek, Karg, 1994)

Reported difficulties with wheelchair securement and occupant restraint systems (Linden, Kamper, Reger, Adams, 1996)

Slide 4
Restraint-Fit and Injury Risk

Anchor location effects injury risk (Bertocci et al., 1996)

Poor restraint fit:

• Abdominal injuries due to submarining
• Lumbar vertebra injuries during frontal impact
• Chest and head injuries
• Secondary injuries due to impacting environment
  (Adomeit & Heger, 1975, Leung et al., 1985, Bertocci et al., 1996, Horsch et al., 1991, Bohlin et al., 1975)

Slide 5
Wheelchair Securement Technology

Tested to withstand a 20g / 30mph crash

Graphic Description: three photographs: a front view of a wheelchair with a belt type securement system, a side view of a manual wheelchair with a belt type 4-point tiedown system, and aide view of a power chair with an automated docking system securing the rear of the wheelchair.

Slide 6
Occupant Restraint Technology

Upper Torso and Pelvic Restraint Restraint Facts:

• 45% fatal injury reduction
• 50% serious injury reduction)
• Every hour, > 1 American dies due to lack of restraint use (NHTSA, 1999

Graphic Description: black and white drawings of a side view and front view of a person in a wheelchair with an upper torso and pelvic restraint.

Slide 7
Occupant Restraint Installation

Graphic Description: side view and front view photographs of a person in a wheelchair with an upper torso and pelvic restraint and a 4-point tiedown system.

Slide 8
Occupant Restraint Installation

Wheelchair tie-down system

• Upper torso restraint anchor
• Upper torso restraint buckle
• Pelvic restraint receiver
  

Wheelchair securement

• Upper torso restraint anchor
• Pelvic restraint receiver

Graphic Description: Drawing of an upper torso restraint anchor point attached to the bottom of a flip up seat.
Drawing of an upper torso restraint anchor point attached to the side structure of a public bus. And showing strap type securements laying on the floor of the bus.

Slide 9
Occupant Restraint Installation

Graphic Description: drawing of an upper torso restraint attached to the bus side structure in between windows and showing the pelvic restraint and wheelchair securement system mounted in rails in the vehicle floor.

Slide 10
Restraint Process: Case 1

Wheelchair structure prevents upper torso restraint use

Seating system setup prevents proper pelvic restraint use

Graphic Description: photograph of person in power chair with a laptray and an AAC device. Another person is making an attempt to restrain the individual in the wheelchair with an upper torso restraint, but the laptray, armrests and AAC device are preventing proper occupant restraint.

Slide 11
Restraint Process: Case 2

Pelvic restraint crosses over armrest

Graphic Description: photograph of a person sitting in power wheelchair and pelvic restraint is wrapped around the armrests, which could be dangerous during frontal impact and injure the wheelchair occupant’s abdominal area.

Slide 12
Restraint Process: Case 3

Upper torso restraint falls from shoulder

Pelvic restraint buckle on abdominal area

Graphic Description: photograph of a person sitting in a manual wheelchair. The upper torso restraint is barely touching the shoulder and will most likely completely slide off the shoulder during frontal impact, posing a threat on the occupant who might impact the vehicle interior.

Slide 13
Survey among Wheelchair Users

Obtain user feedback on use, comfort and belt fit of currently installed wheelchair occupant restraint systems (WORS)

Individuals using their wheelchair during transport

• Para transit
• Mass transit
• Private vehicle

Phone & www survey: www.wheelchairnet.org

• Multiple Choice
• 44 completed surveys
  

Slide14
Survey Setup

IRB#990680-9906

All subjects use their wheelchair as a motor vehicle seat

Questions:

• Transportation used
• Type of ORS used
• Independent use of ORS
• Restraint complaints (time, comfort, fit, ease of use)
  

Slide 15
Results User Comments

60% choose not to wear a WORS (at a certain time)

70% needs help with WORS

45% finds current WORS time consuming

36% finds WORS provide poor belt fit

36% finds WORS are not comfortable

20% finds WORS difficult to use

Slide 16
Results

WORS in Private Vehicles:

• Quick, Easy & Comfortable to use

WORS in Mass-Transit and Para-Transit:

• Uncomfortable to wear
• Difficult to reach
• Time consuming to use

WORS in Mass-Transit

• WORS are time consuming
• WORS use is intrusive
• Non-availability of WORS in mass transit
• Reported use of non-compliant positioning belts
  

Slide 17
Conclusions

Current WORS ineffective due to:

• Various sized occupant population
• Various wheelchair designs and dimensions
• Restrictive vehicle structure

Current WORS may result in:

• Poor restraint fit
• Reduced user comfort and therefore reduced usage
• Restraint related injuries during impact
• Increased risk of occupant injury during impact
  

Slide 18
Future Steps

Detailed WORS usability issues

Determine user requirements for optimized ORS

Type of wheelchair used during transportation

Wheelchair securement type

Injury occurrence while seated in wheelchair (severity level)

Wheelchair occupant anthropometrics

Slide19
Future Steps

Need for alternative and improved w/c occupant restraint technology:

• Safe
• Comfortable
• Independent to use

Graphic Description: a diagram that graphically shows the relation of technical product requirements and wheelchair user needs to accomplish a wheelchair integrated restraint system that is crash proof, easy to use, comfortable and according to the user needs.

Slide 20
Acknowledgements

This study is supported through:

• NIH-STTR
• NIDRR: RERC on Wheeled Mobility
  

Slide 21
Thank You For Your Attention

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Updated: March 14, 2002