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RERC WTS 1 Research Section

SP-1b: In-Depth Investigation of Injuries to Wheelchair-Seated Drivers and Passengers in Motor-Vehicle Crashes and Non-Impact Vehicle Maneuvers

Task Leader: Lawrence Schneider, Ph.D.

Co-investigators: Joel MacWilliams and Jamie Moore at UMTRI, Greg Shaw, Ph.D. at UVA


In-Depth Investigations of Motor-Vehicle Crashes and Moving-Vehicle

Decription | Cover letter | Poster


Progress Report May 1, 2003 | Progress Report May 1, 2004
Progress Report May 1, 2005 | Progress Report May 1, 2006
5 year report June 1, 2006


This Task will involve collaboration with numerous personnel affiliated with manufacturers, van modifiers, and transportation providers, and other organizations that will comprise the crash/incident notification network. For example, it is planned to involve representatives of WTORS companies, such as Bob Josephs of Sure Lok and Jean Girardin of Q’Straint, representatives of wheelchair companies, such as Bob Fitzgerald of Permobil, Steve Keyser and others at Sunrise Medical, Lee Sheffield at Invacare, and Ruth Lytle at Everest &Jennings, and representatives of school transportation groups such as Mike Wagner of Alpha Bus Company in Chicago, Doug Cross of AC Transit in Oakland California, and Bette Cotzin of Washtenaw Intermediate School District in Ann Arbor.

In addition, this Task will involve collaboration with other crash investigation programs, such as the NASS, FARS, and CIREN, and other crash investigation organizations such as Dynamic Sciences, Inc., and the SAE Accident Investigation Research and Practices Committee. Finally, the Task will establish collaborations with government agencies such as the NHTSA the Veteran Administration, and the FTA.

Duration/Staging of Task

This is a 60-month research task. During the first 12 months, a crash incident notification network will be established and new crash-investigation variables that are unique to the wheelchair-seated occupant situation will be established. Crashes and incidents involving wheelchair seated passengers and drivers will be performed in Years 2 through 5.

Research objectives

The goal of this Task is to identify, and conduct in-depth investigations of, crashes and other moving-vehicle, non-impact incidents that result in injuries to wheelchair-seated drivers and passengers traveling in different types of motor vehicles. The in-depth investigations will examine the conditions, circumstances, and other critical factors involved in identified crashes and incidents, and will document the specific occupant injuries and outcomes. In particular, by conducting in-depth investigations of moving motor-vehicle events that involve wheelchair-seated occupants, it is hope to:

  1. identify areas and issues of motor-vehicle injuries that may be unique to wheelchair-seated occupants in different types and sizes of vehicles and transportation services,
  2. document injury scenarios involving use of inappropriate procedures (e.g. side facing) and tiedown/restraint and wheelchair equipment that does not comply with current voluntary standards,
  3. evaluate the performance wheelchair and WTORS that comply with current standards and recommended practices, and
  4. characterize, in relation the able-bodied population, the extent, incidence, and nature of injuries to wheelchair-seated occupants in different types and sizes of vehicles,

In addition, in the process of conducting and completing this task, it is hoped to establish an increased awareness among current crash-investigation programs of the need to identify and code for occupants seated in wheelchairs, and to implement and promote a set of data variables and measurement procedures that are uniquely related to the wheelchair-seated occupant.

Anticipated Outcomes

The results of this task will provide specific and detailed information on the incidence, extent, and nature of injuries to wheelchair-seated occupants in different types of motor vehicles and transportation services. Where appropriate, this information will include estimates of the crash severity and impact type, as well as details about the type of wheelchair securement and occupant restraint system, and the type of wheelchair involved. This information will help identify issues of occupant protection that may be unique to wheelchair-seated occupants, evaluate the real-world feedback on the performance of wheelchairs and WTORS that comply with current standards, and generally define the extent, incidence, and nature of injuries to wheelchair-seated occupants in different types and sizes of vehicles. As a result of this task, it is expected that awareness of the need for information related to wheelchair-seated occupants will be increased, and existing crash-investigation programs will add new variables and coding related to the special circumstances of wheelchair-seated occupants. Along with results from Tasks 1a and 1c, the results will help transit providers make more informed decisions on policies and procedures involving trade-offs between wheelchair occupant safety and operational efficiency.

References

Augenstein, J.S., Digges, K., Cooper, G., Hoyt, D.B., Eastman, B., Burgess, A., Dischinger, P., Scally, J., Wang, S., Schneider, L., Siegel, J., Loo, G., Grossman, D., Rivara, F., Eichelberger, M., Gotschall, C., Lombardo, L., Brown, L., Eppinger, R. The Ciren Experience, Proceedings of the 16th International Technical Conference on the Enhanced Safety of Vehicles, 1998 Vol. 2, p 1325-1336.

Baker, J.S. Traffic Accident Investigation Manual, The Traffic Institute Northwestern University, 1976 Evanston Illinois.

Cooley, P. In-Depth Investigation of Crashes in Michigan Involving Children. The University of Michigan Transportation Research Institute, 1984.

Gotschall, C.S., Dougherty, D.J., Eichelberger, M.R., Bents, F.D. Traffic-Related Injuries to Children: Lessons From Real World Crashes, Proceedings of 42nd Association for the Advancement of Automotive Medicine, 1998, p 165-177.

Huelke, D.F., Sherman, H.W. Methodology of Injury Causation Investigation, Proceedings of the Collision Investigation Methodology symposium, 1969, p 276-285.

Huelke, D.F.; Moore, J.L. 1993. “Field investigations of the performance of air bag deployments in frontal collisions.” Accident Analysis and Prevention, Vol. 25, No. 6. Pp. 717-730.

Huelke, D. F. and Compton, C. P. 1995. “Rear seat occupants in frontal crashes: adults and children: the effects of restraint systems.” In International IRCOBI Conference on the Biomechanics of Impacts. 1995. Proceedings. Bron, IRCOBI, 1995. Pp. 421-427.

Huelke DF, Gilbert RJ, Schneider LW, Upper-Extremity Injuries from Steering Wheel Airbag Deployments. SAE paper no. 970493. Motor Vehicle Safety Design Innovations, pp. 111-116. SAE, Warrendale, PA, 1997.

Huelke DF, Schneider LW, Reed MP, Gilbert RJ, Facial, Periorbital and Ocular Injuries Related to Steering-Wheel Airbag Deployments. SAE paper No. 970490. Motor Vehicle Safety Design Innovations, pp. 97-102. SAE, Warrendale, PA, 1997.

Klinich KD, Schneider LW, Moore JL, Pearlman MD, Investigation of Crashes Involving Pregnant Occupants. Proc. 44th Annual Conference of the Association for the Advancement of Automotive Medicine, pp. 37-55. AAAM, Chicago, IL, 2000. Sponsor: General Motors Corporation.

National Automotive Sampling System- Crashworthiness Data System, 1995 – 1997 The National Highway Traffic Safety Administration, U.S. DOT.

Otte, D. Review of airbag effectiveness in real life accidents demands for positioning and optional depoloyment of airbag systems. Hanover Medical University, Germany, 1995 Stapp Car Crash Conference. SAE Paper No. 952701.

Robbins, D.H., Melvin, J.W., Huelke, D.F., Sherman, H.W. Biomechanical Accident Investigation Methodology Using Analytical Techniques, Proceedings of 27th Stapp Car Crash Conference with International Research Committee on Biokinetics of Impacts, 1983, paper 831609, p 115-127.

Thomas, P. and Frampton, R, Injury Patterns in Side Collisions – A New Look with Reference to Current Test Methods and Injury Criteria. Proceedings of the Stapp Car Crash Conference, October 1999. pp. 1- 12.

Tunbridge, R.J., Everest, J.T., Wild, B.R., Johnstone, R.A. An In-Depth Study of Road Accident Casualties and Their Injury Patterns. Transport and Road Research Laboratory report 136, Berkshire, UK, 1988.


Progress Report May 1, 2003

During the first year of the RERC-on-WTS program, much of the foundation for conducting and documenting these investigations was established. These foundational tasks include enhancing the existing set of variables in the UMTRI crash/injury database to include variables that are specific to the investigation of wheelchair-seated occupants, establishing a network of contacts by which UMTRI crash investigators will be notified in a timely manner of motor-vehicle crashes and incidents in which a wheelchair-seated occupant was involved, establishing the specific protocol for conducting these investigations, and obtaining IRB approval for carrying out this task in Years 2 through 5.

A list of additional variables has been developed and implemented in the UMTRI crash/injury database. They include information about the orientation of the wheelchair-seated occupant in the vehicle, the type of wheelchair securement and occupant restraint systems available in the vehicle and whether they were being used correctly, the type of wheelchair involved and whether it was provided with the transit option, and the specific nature of any damage to components of wheelchair tiedowns, occupant restraint systems, and the involved wheelchair. As is typical of UMTRI crash investigations, the results obtained will be used to perform an analysis of the causes of these injuries, and the roles that the wheelchair, the securement system, and the occupant restraints may have played in preventing or causing injuries to the wheelchair-seated occupant, or to other occupants of the vehicle.

key factor in the success of Task 1b is the establishment of an effective notification network. In this regard, a letter describing the project and the “wanted” poster (100kb) was distributed at the annual meeting of the National Manufacturers Equipment Dealers Association (NMEDA) and numerous contacts were made by personally visiting with various transit groups and vehicle modifiers in their exhibit booths. In addition, contacts are continuing to be made with product manufacturers, clinicians, transit providers, school districts, and other crash investigation programs such as the Crash Injury Research Engineering Network (CIREN), the National Automotive Sampling system (NASS), and the National Highway Traffic Safety Administrations (NHTSA's) Special Crash Investigation (SCI) program. Most recently, RERC participants in this task attended the annual meeting of the American for Public Transportation Association where additional contacts with public transit providers were made.

The actual initiation of new investigations has been delayed and is about six months behind schedule. This is due, in large part, to the increased complexity of the IRB applications process that results from new informed-consent requirements imposed by the Health Insurance Portability and Accountability Act (HIPPA). Approval for conducting these investigations of crashes and moving motor-vehicle incidents involving wheelchair users was obtained in Year 1 from the University of Michigan's Social and Behavioral IRB Committee and has been successfully renewed with the new HIPPA requirements, including a waiver from written consent to conduct a phone interview with the participating individual or their legal representative. Approval from the IRB Committee at the University of Pittsburgh is pending but is expected soon. In the meantime, several crashes involving wheelchair seated occupants have been obtained from the NHTSA’s SCI project and a few other crashes have been investigated as a part of UMTRI’s regular crash investigation program.


Progress Report May 1, 2004

Status of task:

This task has been delayed 1 year due to IRB approval delays.

Progress to date:

Obtaining approval from the IRB Committee at the University of Pittsburgh to conduct accident investigations and phone interviews with wheelchair users involved in the accidents based on verbal consent took significantly longer than expected, but approval was finally obtained in March 2004. Since obtaining University of Pittsburgh IRB approval, two new investigations have been conducted. One investigation involved an onsite inspection of the vehicle and accident scene and the other involved communication with the transit company who provided photographs of the involved vehicle.

The crash that resulted in an on-site investigation was a multi-turn rollover of a paratransit van carrying two wheelchair-seated occupants. Both occupants were facing forward in the van and their wheelchairs were secured using four-point tiedown straps. However, the rear track of one of the wheelchair tiedowns tore free from the van floor during the rollover due to inappropriate fasteners and attachment hardware. This resulted in release of the rear tiedown straps as well as release of the occupant belt restraint system. The elderly wheelchair-seated passenger became unrestrained and sustained fatal injuries in the rollover due to impact with vehicle interior structures. The wheelchair of the second wheelchair-seated passenger was effectively secured during the rollover but the occupant of this wheelchair was not properly restrained and also came out of the wheelchair during the rollover. However, he was fortunate to have sustained only minor contusions even though he contacted the vehicle interior after coming out of his wheelchair.

The second investigation involved a right-side impact of a full-size van in which the driver was seated in a wheelchair that was secured by a popular driver docking securement system. Because the driver was on the side opposite to the impacted side, this is referred to as a far-side impact for the case occupant. Since these types of crashes will be the primary focus of Task 2b, this crash is of particular interest at this time. Normally, belt-restrained occupants are not as likely to be seriously injured in far-side impacts as they are in nearside impacts where the striking vehicle displaces the door or sidewall directly into the nearside occupant at high speed. However, the key to injury reduction in far-side impacts is effective seat securement and occupant restraint to keep the occupant from making contact with the struck side of the vehicle, and it is unknown how wheelchairs and WTORS designed for frontal impact protection will perform in far-side impacts. In the particular case that was investigated, the securement system and belt restraints kept the wheelchair and driver in position and prevented injurious contact of the driver with the right side of the vehicle.

The NMEDA conference was attended again this year with the goal of reminding van modifiers of our interest in conducting in-depth investigations of accidents involving wheelchair-seated occupants. “Wanted” posters were distributed and exhibitors were reminded to notify UMTRI investigators in a timely manner when they become aware of any accidents or crashes involving their products. They were also reminded that all data collected in these investigations are protected from access through the freedom of information act by Michigan House Bill 4377 and that any presentations or publications of the results will be in an anonymous form so as not to identify individuals or companies. A follow-up letter is being prepared and will be sent out to NMEDA members, manufacturers, and transit providers, to further establish the accident notification system.


Progress Report May 1, 2005

Progress to date:

Information on 18 crashes involving 19 wheelchair-seated occupants has been collected, and five-page case summaries have been drafted for fourteen of the cases. Each summary includes a description of the crash/incident situation with a scene drawing, key crash and vehicle damage variables, photos of the vehicle exterior and interior, and a summary of occupant injuries and suspected injury sources. Of the 18 cases, eleven are full in-depth investigations and six are minor investigations for which information was obtained from news articles, legal case documents, and/or police accident reports. Data from the cases are being coded for inclusion in an RERC-WTS wheelchair-occupant crash/injury database.

In thirteen of the cases, the primary event to the vehicle with a wheelchair-seated occupant was a frontal collision, in two cases it was a side impact, in one case a frontal impact was followed by a rear impact, and in two cases the vehicle was involved in a rollover. Frontal crashes were classified as severe, moderate, or minor based on whether the estimated delta V was greater than 30 mph, between 15 and 30 mph, or less than 15 mph, respectively. Side impacts were similarly classified based on whether the estimated lateral delta V was greater than 15 mph, between 8 and 15 mph, or less than 8 mph. Rollover events were classified as severe if they involved six or more quarter turns. Based on these classifications, five of the crashes were severe (three frontal, one side, one rollover), four were moderate (three frontal, one frontal then rear), seven were minor (all frontal), and crash severity was unknown for two cases (one rollover, one side).

Of the nineteen wheelchair-seated occupants, eight were drivers, one was a right-front passenger, seven were second-row passengers, and three were in the third or fourth row. Eight of these occupants were using powered wheelchairs and five were using manual wheelchairs, while the type of wheelchair was not specified for the remaining six occupants. All of the drivers' wheelchairs were secured to the vehicle by a docking securement device, while all of the wheelchairs used by passengers were secured by 4-point, strap-type tiedowns. In one severe frontal impact, the docking system severely deformed but it did not release the wheelchair. In another case, the fasteners attaching the anchorage track to the vehicle floor pulled loose during a severe rollover. No other tiedown failures were noted in any of the cases.

Ten occupants were restrained by after-market three-point (lap/shoulder) belts, and three of these were seated in the front row and were also restrained by an airbag that deployed during a frontal impact. One driver was not using a belt restraint, but the airbag deployed in a moderate frontal collision. Two passengers were restrained only by the postural supports on the wheelchair. Four other cases also involved improper or incomplete restraint of the wheelchair occupant: shoulder belt and postural lap belt, improperly routed lap belt, improperly positioned lap belt, and lap belt only. One occupant was completely unrestrained. The restraint conditions are currently unknown for one wheelchair-seated passenger.

In these crashes, six wheelchair-seated occupants died as a result of injuries sustained, but only two of these occupants were properly restrained by a three-point belt. One of the properly restrained fatally injured occupants was involved in a severe head-on frontal crash with a bus that resulted in extensive intrusion and the death of both the wheelchair-seated driver and the right-front passenger who was not in a wheelchair. The other properly restrained wheelchair user who was fatally injured was restrained by a three-point belt, but the tiedown track broke free from the floor when the vehicle entered an eight-quarter-turn rollover, which allowed the wheelchair to tip over and the occupant to be ejected from the wheelchair and sustain fatal head and neck injuries from contact with an unknown interior component.

The remaining four fatal cases involved improperly restrained occupants. One was a severe frontal impact in which the wheelchair-seated driver restrained by an aftermarket vehicle-anchored shoulder belt and a postural lap belt attached to the wheelchair sustained fatal chest injuries from shoulder-belt loading. The second involved a wheelchair-seated passenger in a severe frontal impact where the lap belt was routed over the arms of the wheelchair, which placed the belt high over the passenger's abdomen and resulted in fatal abdomen, spine, and thorax injuries. The third fatality occurred when the occupant was restrained by only a lap belt that was positioned high on the abdomen and led to fatal abdominal injuries in a moderate frontal impact. In the fourth fatality resulting from improper restraint, the driver, who was not wearing the lap/shoulder belt, sustained fatal thoracic injuries from close-proximity airbag loading in a moderate frontal impact that was followed by a rear impact which caused her to be ejected from her wheelchair into the back of her vehicle.

Three case occupants sustained moderate injuries. One case involved a vehicle rollover in which the three-point belt-restrained wheelchair-seated male passenger was ejected out of the side window of a paratransit van and broke both legs. The cause for the release of the three-point belt is believed to be the interaction of the buckle release button with the wheelchair wheel rim during the rollover. The second case involved a minor frontal impact in which the right-front passenger, who was restrained by the lap/shoulder belt and an airbag, sustained serious upper and lower extremity injuries. The third case was a moderate frontal impact in which the driver, who restrained by the lap/shoulder belt and an airbag, sustained serious thorax and abdomen injuries from shoulder-belt loading.

Seven of the case occupants sustained minor injuries. In one case, a second-row female passenger was involved in a minor frontal impact, but the restraint system being used is currently unknown. Another case involved a driver who was involved in a minor frontal impact while restrained by a modifed lap/shoulder belt and an airbag. A third minor injury case involved a driver restrained by a lap/shoulder belt in a far-side impact moderate far-side impact. Both the wheelchair tiedown and occupant restraint kept the wheelchair and driver in the driver station, thereby preventing serious injury. The fourth minor injury case involved a passenger who was involved in a moderate frontal impact while restrained only by postural chest and lap belts, but sustained minor head and hand injuries when he came out of his chair after the postural belts released from their wheelchair attachments. The fifth minor injury case involved an unrestrained second-row elderly male passenger who very fortunate to sustain only minor injuries when he was ejected from his wheelchair during a severe rollover. The sixth case involved a female driver restrained only by a postural lap belt in a severe left-side T-type impact followed by a single quarter-turn rollover. This driver sustained only minor injuries when she fell out of her chair during the rollover after the postural belt released. The seventh minor-injury case involved a driver who was effectively restrained by a lap/shoulder belt during a minor frontal impact.

Efforts are underway to increase notifications of crashes and other moving-vehicle incidents involving wheelchair-seated occupants by placing advertisements in law-enforcement newsletters of several states, such as the Michigan Association of Traffic Accident Investigators (MATAI). In addition, UMTRI investigators receive email notification from "Google News Alert" when a news article is published with the key words "wheelchair," "crash," and "equipped."

Additional approaches to increasing notifications of crashes involving wheelchair-seated occupants are also being explored, but involve advertising directly to disabled individuals, both in print and electronically, using specialized publications, support organizations, and online wheelchair-user forums. However, implementing these recruitment approaches requires modification to the recruitment protocol that has received IRB approval. Modified IRB applications are therefore being prepared for submission.


Progress Report May 1, 2006

Progress to date:

Six new cases were completed and added to the UMTRI wheelchair crash/injury database, bringing the new total to twenty-four cases. These cases span a range of impact directions and severities and include eight wheelchair-seated drivers whose wheelchairs were secured by a docking type tiedown. Theses cases also include six occupants who died from injuries or complications from injuries sustained in the motor-vehicle accidents, with the severities of the vehicle events resulting in these fatalities varying widely.
The most significant finding to date is a high percentage of wheelchair users who are not properly restrained or who are not restrained at all. Thus, while very few problems of effective wheelchair securement using either docking or four-point strap-type tiedowns have been noted within these twenty-four cases, many of the case occupants sustained serious-to-fatal injuries due to lap and shoulder belts that were not properly positioned or used. These include:

  1. occupants restrained by lap belts that were placed over the wheelchair armrests so that the belt webbing was over the abdomen rather than on the pelvis and/or not in good contact with occupant's body,
  2. occupants restrained by shoulder belts that were loosely draped in front of a wheelchair-seated driver without a lap belt,
  3. occupants restrained by only a lap belts without a shoulder belt, and
  4. occupants who were restrained only by a postural belt while a crash-tested lap/shoulder belt was left hanging on the vehicle sidewall.

The reasons for improper and non-use of available lap and shoulder belts in the real-world appears to be due two primary factors. One is the lack of training by family members, caregivers, and professional drivers. The second is the difficulty of placing vehicle-anchored belt restraints on the wheelchair user due to interference by wheelchair components.

The high rate of wheelchair users sustaining serious injuries in relatively minor incidents due to improper belt restraint also emphasizes observed in the cases investigated to date, suggests that the requirement for rating wheelchair accommodation of belt restraints in WC/19 needs to be raised to a higher priority in manufacturer and consumer awareness, and perhaps modified in the standard to require that all WC19 wheelchairs to achieve an "A" rating. It also indicates the potential benefits of using wheelchair-anchored crash-tested pelvic belts.


5 year report June 1, 2006

This task has sought to investigate the specific crash, vehicle, occupant, and restraint factors surrounding adverse real-world events involving wheelchair-seated occupants of motor vehicles.  For the purposes of this study, an adverse event is considered any moving-vehicle incident that has the potential to result in injury to the wheelchair occupant or to other occupants in the vehicle due to the presence of the wheelchair occupant.  To a large extent, adverse events are collisions or vehicle rollovers, but they also include emergency vehicle maneuvers, such as emergency braking or sharp turning in which the inertial forces may present a potentially injurious scenario to the wheelchair user (e.g., tipping of wheelchair to the side, unrestrained wheelchair user coming out of wheelchair).  Because the goal of the study is to collect as much objective and factual information as possible through inspection and measurement of the potentially damaged vehicle, wheelchair tiedown, occupant restraint system, and wheelchair that were involved in the incident, it is important to the success of the study to obtain timely notification of real-world events.  Investigations also involve interviewing the wheelchair user or their legal representative and, if appropriate, obtaining information from a treating medical facility about the specific injuries to the wheelchair-user that resulted from the accident.

Although it had been hoped to investigate at least eighty real-world events over the course of the RERC, this goal has not been realized due, in part, to delays obtaining human use approval from institutional review boards at both the University of Pittsburgh and the University of Michigan.  In addition, the numbers of notifications of potential cases received from a network of product manufacturers, transit providers, clinicians, seating clinics, and vehicle modifiers has been low, probably due to fears of liability, even though all data from the study are presented in an objective manner without assignment of fault, and all personal, product, and location identifiers are removed from the case data and images.

In spite of these difficulties and limitations, the study has assembled data from twenty-four real-world cases involving wheelchair-seated occupants.  These include cases that were investigated by UMTRI crash investigators as well as several cases obtained from the National Automotive Sampling System (NASS), from website notifications (Google News Alert), and from cases that were in litigation.  Information on each of these cases is now summarized in a four-to-five page summary report that documents the essential factors of the case using narrative descriptions, scene drawings, and photos.  Each summary report is divided into several sections that include the a brief description of the crash/incident scenario, the summary of the damage to the vehicle or vehicles involved, including measurements of external (crush) and internal (intrusions), information on the case occupant and his/her injuries, and information on the condition of the wheelchair, wheelchair tiedown, and occupant restraint that were available and used.  Each report also includes a section that reconstructs the occupant and wheelchair kinematics and that documents the most likely causes of occupant injuries, or lack of injuries, in relation to the performance of equipment that was being used.  These results are coded and input to a wheelchair-user crash/injury database that contains the full range of standard vehicle, crash, and occupant variables used in typical crash investigations, but that also includes numerous additional variables that are unique to the situation of wheelchair-seated occupants. The latter include the types of wheelchair securement systems, the type of occupant restraint system and locations of anchor points, the type of wheelchair and its position and orientation in the vehicle, and the use of any postural supports.  They also include the post-event or post-crash condition of these components.

The twenty-four cases that have been documented to date span a range of impact directions and severities and include eight wheelchair-seated drivers whose wheelchairs were secured by a docking type tiedown.  Theses cases also include six occupants who died from injuries or complications from injuries sustained in the motor-vehicle accidents, with the severities of the vehicle events resulting in these fatalities varying widely. 

The most significant observation from these cases to date is a high percentage of wheelchair users who are not properly restrained or who are not restrained at all.  Thus, while very few problems of effective wheelchair securement using either docking or four-point strap-type tiedowns have been noted within these twenty-four cases, many of the case occupants sustained serious-to-fatal injuries due to lap and shoulder belts that were not properly positioned or used.  These include:

  1. occupants restrained by lap belts that were placed over the wheelchair armrests so that the belt webbing was over the abdomen rather than on the pelvis and/or not in good contact with occupant’s body,
  2. occupants restrained by shoulder belts that were loosely draped in front of a wheelchair-seated driver without a lap belt,
  3. occupants restrained by only a lap belts without a shoulder belt, and
  4. occupants who were restrained only by a postural belt while a crash-tested lap/shoulder belt was left hanging on the vehicle sidewall. 

The reasons for improper and non-use of available lap and shoulder belts in the real-world appears to be due two primary factors. One is the lack of training by family members, caregivers, and professional drivers.  The second is the difficulty of placing vehicle-anchored belt restraints on the wheelchair user due to interference by wheelchair components. 

With regard to the latter, Section 19 ANSI/RESNA WC/Volume 1 Wheelchairs Used as Seats in Motor Vehicles requires that wheelchairs that comply with this standard (i.e., WC19 wheelchairs) be rated for their “accommodation of vehicle-anchored belt restraints.”  At the present time, it is only necessary for the manufacturers to perform the rating test and disclose the results (A = good, B = acceptable, C = poor) in their pre-sale literature. 

The high rate of wheelchair users sustaining serious injuries in relatively minor incidents due to improper belt restraint also emphasizes observed in the cases investigated to date, suggests that the requirement for rating wheelchair accommodation of belt restraints needs to be raised to a higher priority in manufacturer and consumer awareness, and perhaps modified in the standard to require that all WC19 wheelchairs to achieve an “A” rating.  It also indicates the potential benefits of using wheelchair-anchored crash-tested pelvic belts.

In an effort to increase notifications of crashes and other moving-vehicle incidents involving wheelchair-seated occupants advertisements are now being placed in law-enforcement newsletters of several states, such as the Michigan Association of Traffic Accident Investigators (MATAI).  In addition, the IRBs for this project were renewed with an expansion of recruiting methods to allow for:

  • sending emails with a brief description of the project and the wanted poster to organizations and groups that include potential participants (i.e., wheelchair users) as members,
  • posting the “wanted” poster advertisement on the RERC WTS website (rercwts.pitt.edu) and on other websites that wheelchair users are likely to visit,
  • placing wanted poster ads and information about the study in consumer publications read by wheelchair users and their caregivers.

The “Wanted” poster has been modified accordingly to address wheelchair users more directly and the new poster ad is being placed on the travelsafer.org and rercwts websites.   Once the ad is on-line, wheelchair user groups on the web will be referred to the these websites for more information on the study and how to contact UMTRI crash investigators.

Last updated: August 18, 2006

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Acknowledgement:

Department of Education, Washington DC
This Rehabilitation Engineering Research Center (RERC) on Wheelchair Transportation Safety
is funded by NIDRR grant #H133E060064

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