[Show abstract][Hide abstract] ABSTRACT: Ease of use, comfort, security, and independent use of three types of wheelchair securement systems were evaluated in a large accessible transit vehicle by 20 wheelchair and scooter users. The securement systems included a 4-point tie-down system, a prototype autodocking system, and a prototype rear-facing wheelchair passenger (RF-WP) system. Study participants took a 15-minute city ride and completed a survey. Participants responded positively to the autodocking and RF-WP systems that were quicker and easier to use and allowed more independent use than the 4-point tie-down system (p < 0.001). There was concern regarding the RF-WP system that rear-facing travel made it more difficult to see upcoming stops and was less comfortable than a forward-facing ride and that the system may damage wheelchair wheels during use. The majority of participants preferred using an autodocking system because it allowed secure and independent forward-facing travel. Participants found it undesirable, however, that a wheelchair-mounted docking adaptor was needed to use the autodocking system. Study results indicate a need for improved securement systems for forward-facing use that do not require a wheelchair adaptation and can be easily and independently used by wheelchair and scooter users.
Preview · Article · Jan 2011 · The Journal of Rehabilitation Research and Development
[Show abstract][Hide abstract] ABSTRACT: Beginning in 2000, a study of discomfort experienced by wheelchair users and development of technology solutions were undertaken. This research culminated with the present study of a new technology targeting sitting discomfort. Support for development of the "Butt Scooter" prototype and its testing was provided through an NIH research grant. Investigators tested a prototype device, called the "Butt Scooter," and conducted a focus group to obtain expert clinical opinions about the potential usefulness of the prototype. Subject testing of the prototype device followed a single subject design (ABABA). Subjects self-administered the Tool for Assessing Wheelchair disComfort (TAWC) to evaluate their discomfort levels. Results from three subjects are reported. All three expert therapists participating in the focus group responded favorably to the prototype. In summary, results from subject testing were somewhat mixed with regard to discomfort management, however all subjects commented positively on the features of the device.
No preview · Article · Aug 2010 · Assistive technology: the official journal of RESNA
[Show abstract][Hide abstract] ABSTRACT: The Rehabilitation Engineering Research Center on Wheelchair Transportation Safety held a state-of-the-science workshop on wheelchair transportation. The workshop had three purposes: reviewing and documenting the status of wheelchair transportation safety, identifying deficiencies, and formulating, discussing, and prioritizing recommendations for future action. The final goal was to disseminate the workshop outcomes for utilization in formatting future research priorities. A nominal group technique was used to facilitate focused open discussion by knowledgeable persons, resulting in the identification and ranking of existing deficiencies according to priority. Participants then formulated potential short-term solutions and speculated what wheelchair transportation safety should be in the future. This document presents four white papers, prepared prior to the workshop and modified according to participant feedback, and summarizes the outcomes of the workshop. The results identify and prioritize recommendations for future action.
No preview · Article · Sep 2009 · Assistive technology: the official journal of RESNA
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to examine the effectiveness of a new user-adjustable wheelchair seating system designed to relieve discomfort for long-duration wheelchair users.
This objective was carried out using the newly developed Tool for Assessing Wheelchair disComfort (TAWC) as the primary outcome measure. Two wheelchair users each tested two different designs and feedback from the wheelchair users regarding the first design was used to guide development of the second design. A single-subject research methodology was used, allowing long-duration (up to 2 wks per test) evaluation of the wheelchair seating systems and comparison of subject discomfort levels with those experienced during a baseline period using their own wheelchairs. The experimental wheelchair seating systems employed existing automotive seating with embedded pneumatic bladders that allowed adjustment of the seat and back-support characteristics. The test wheelchair also had tilt, recline, and elevating leg rests.
The two subjects completed limited periods of testing with the first design, both finding poor results with either stable or increased levels of discomfort. Subject feedback was used to redesign the wheelchair seat. After redesign, both subjects tested the second design and found it substantially more comfortable.
The selected research methodology was a very positive method for a progressive wheelchair seating design and the second design provided improved comfort for both users when compared with that experienced using their own wheelchairs and the first test wheelchair. Future research of this type of user-controlled technology is recommended.
No preview · Article · Jan 2008 · American Journal of Physical Medicine & Rehabilitation
[Show abstract][Hide abstract] ABSTRACT: The purpose of this research was to determine the clinical usefulness of the Tool for Assessing Wheelchair disComfort (TAWC) by examining floor and ceiling effects and responsiveness when used with two groups of wheelchair users--one known to have experienced real changes in discomfort levels and the other with unchanged levels.
In a retrospective analysis of data from two previous studies, change scores were compared across two groups of subjects--one stable group (NON-CHANGERS) and one experiencing a seating intervention (CHANGERS) intended to decreased seating discomfort.
No significant floor or ceiling effects were found. The average General Discomfort Score (GDS) change among the NON-CHANGERS was 2.0 (with a possible score range of 13-91) and average Discomfort Intensity Score (DIS) change was 1.8 (with a possible score range of 8-99) for the same group. Conversely, average GDS change among the CHANGERS was 8.7 and the average DIS change was 7.7. Additionally, both scores demonstrated a moderate effect size (d) for two tested treatments (GDS = 0.53 and 0.50, DIS = 0.31 and 0.33) and the standardized response means were 0.78 and 0.77 for the GDS and 0.80 and 1.2 for the DIS.
All analyses indicate good responsiveness of the TAWC, supporting its use clinically and in future research.
No preview · Article · Apr 2007 · Disability and Rehabilitation Assistive Technology
[Show abstract][Hide abstract] ABSTRACT: Discomfort is a common problem for wheelchair users. Few researchers have investigated discomfort among wheelchair users or potential solutions for this problem. One of the impediments to quantitative research on wheelchair seating discomfort has been the lack of a reliable method for quantifying seat discomfort. The purpose of this study was to establish the test-retest reliability, internal item consistency, and concurrent validity of a newly developed Wheelchair Seating Discomfort Assessment Tool (WcS-DAT). Thirty full-time, active wheelchair users with intact sensation were asked to use this and other tools in order to rate their levels of discomfort in a test-retest reliability study format. Data from these measures were analyzed in SPSS using an intraclass correlation coefficient (ICC) model (2,k) to measure the test-retest reliability. Cronbach's alpha was used to examine the internal consistency of the items within the WcS-DAT. Concurrent validity with similar measures was analyzed using Pearson product-moment correlations. ICC scores for all analyses were above the established lower bound of .80, indicating a highly stable and reliable tool. In addition, alpha scores indicated good consistency of all items without redundancy. Finally, correlations with similar tools, such as the Chair Evaluation Checklist and the Short Form of the McGill Pain Questionnaire, were significant at the .05 level, and many were significant at the .001 level. These results support the use of the WcS-DAT as a reliable and stable tool for quantifying wheelchair seating discomfort. Its application will enhance the ability to assess and to research this important problem and will provide a means to validate the outcomes of specialized seating interventions for the study population of wheelchairs users.
No preview · Article · Feb 2005 · Assistive technology: the official journal of RESNA
[Show abstract][Hide abstract] ABSTRACT: This study examined the concept of seating discomfort in a population of full-time wheelchair users with intact sensation. The goal was to construct a tool that would quantify seating discomfort experienced by wheelchair users. Ten participants were interviewed using ethnographic interview techniques. Data were analyzed using a cross-classifying matrix to examine commonalities among the 10 participants' responses. There were 16 discomfort and 13 comfort descriptors used by the participants. Of these, eight discomfort and five comfort descriptors were selected to include in the Wheelchair Seating Discomfort Assessment Tool (WcS-DAT). The discomfort descriptors selected were: aches and pains, need to move, pressure points, feeling poorly positioned, unable to concentrate, instability, not comfortable, and feeling too hot, cold or damp. The comfort descriptors selected were: absence of discomfort, feeling good, having no pain, able to concentrate, and feeling stable. The WcS-DAT also includes general information, such as the amount of time spent sitting and whether the individual was transferred into the chair properly--factors thought to affect discomfort--and ratings of discomfort intensity--in general and differentiated by body area. The WcS-DAT is a comprehensive tool for quantification of wheelchair seat discomfort for this population.
No preview · Article · Apr 2004 · International Journal of Rehabilitation Research
[Show abstract][Hide abstract] ABSTRACT: Regardless of the field, agenda-setting processes are integral to establishing research and development priorities. Beginning in 1998, the National Institute on Disability and Rehabilitation Research mandated that each newly funded Rehabilitation Engineering and Research Center (RERC) hold a state-of-the-science consensus forum during the third year of its 5-year funding cycle. NIDRR's aim in formalizing this agenda-setting process was to facilitate the formulation of future research and development priorities for each respective RERC. In February 2001, the RERC on Wheeled Mobility, University of Pittsburgh, conducted one of the first such forums. The scope encompassed both current scientific knowledge and clinical issues. In preparation, expert interviews were carried out to establish the focus for the forum. Because a stakeholder forum on wheelchair technology had recently been held, opinion favored wheelchair seating as the focus and included the following core areas: seating for use in wheelchair transportation, seated postural control, seating discomfort, and tissue integrity management. The aim of this report is to present a summary of the workshop outcomes, describe the process, and increase awareness of this agenda-setting process in order to enhance future participation in a process that critically influences the field of wheeled mobility.
No preview · Article · Feb 2003 · Assistive technology: the official journal of RESNA
[Show abstract][Hide abstract] ABSTRACT: To promote proper wheelchair securement in transportation, the proposed ANSI/RESNA Standard on Wheelchairs Used as Seats in Motor Vehicles will require that all transit wheelchairs be equipped with four securement points compatible with strap-type tiedowns. Through computer simulations, the location of these securement points has been found to influence wheelchair user response to a frontal crash. This study develops and employs an injury risk assessment method to compare the crashworthiness of various securement point configurations. The comparative injury risk assessment method is designed to predict the risk associated with internalized crash forces, as well as risk associated with secondary occupant impact with the vehicle interior. Injury criteria established by Federal Motor Vehicle Safety Standards and General Motors, along with excursion limitations set by the Society of Automotive Engineers (SAE) J2249 Wheelchair Tiedowns and Occupant Restraint Systems (WTORS) Standard were used as benchmarks for the risk assessment method. The simulation model subjected a secured commercial powerbase wheelchair with a seated 50th percentile male Hybrid III test dummy to a 20 g/30 mph crash. The occupant was restrained using pelvic and shoulder belts, and the wheelchair was secured with four strap-type tiedowns. Results indicated that securement points located 1.5 in to 2.5 in above the evaluated wheelchair's center of gravity provide the most effective occupant protection.
No preview · Article · Apr 2000 · IEEE Transactions on Rehabilitation Engineering
[Show abstract][Hide abstract] ABSTRACT: The Americans with Disabilities Act (ADA) has led to an increased
number of wheelchair users seeking transportation services. Many of
these individuals are unable to transfer to a vehicle and are instead
required to travel seated in their wheelchairs. Unfortunately,
wheelchairs are not typically designed with the same occupant protection
features as motor vehicle seats, and wheelchair seated occupants may be
at higher risk for injury in a crash. To study the effects of crash
level forces on wheelchairs and their occupants, it is useful to
simulate crash conditions using computer modeling. This study has used a
dynamic lumped mass crash simulator, in combination with sled impact
testing, to develop a model of a secured commercial powerbase and
restrained occupant subjected to a 20 g/30 mph frontal motor vehicle
crash. Time histories profiles of simulation-generated wheelchair
kinematics, occupant accelerations, tiedown forces and occupant
restraint forces were compared to sled impact testing for model
validation. Validation efforts for this model were compared to
validation results found acceptable for the ISO/SAE surrogate wheelchair
model. This wheelchair-occupant simulation model can be used to
investigate wheelchair crash response or to evaluate the influence of
various factors on occupant crash safety
No preview · Article · Jul 1999 · IEEE Transactions on Rehabilitation Engineering
[Show abstract][Hide abstract] ABSTRACT: (1) To measure kyphosis and scoliosis in individuals with tetraplegia; (2) to examine the relation between kyphosis and scoliosis and years since injury; and (3) to determine the association between kyphosis and scoliosis and measures of pain, depression, and life satisfaction.
Cross-sectional, case-control study.
University medical center and a free-standing university-affiliated rehabilitation hospital.
(1) Ten individuals with tetraplegia I to 3 years postinjury (NT); (2) 10 individuals with tetraplegia 10 to 20 years postinjury (OT); and (3) 10 control individuals (C) matched to the other subjects on the basis of age, height, and weight.
Radiographic measurements of kyphosis and scoliosis taken in a seated position, pain as measured by the short form of the McGill Pain Questionnaire (SF-MPQ), depression as measured by the Center for Epidemiological Studies-Depression Scale (CES-D), and life satisfaction as measured by the Life Satisfaction Index Assessment (LSIA) and the Craig Handicap Assessment and Reporting Technique (CHART).
No significant differences were seen between the OT and NT groups with respect to age, height, or weight. In addition, no significant differences were found between the NT and OT groups with respect to measures of kyphosis and scoliosis. Individuals with tetraplegia had significantly higher (p < .05) measures of kyphosis (42 + 16.0 ) and scoliosis (14 degrees +/-9.2 degrees) than the C subjects (kyphosis, 32 degrees +/- 7.9 degrees ; scoliosis, 5 degrees+/-3.8 degrees). No correlation was found between scores on the SF-MPQ and degree of kyphosis or scoliosis. Significant differences were seen between the NT and OT groups on both CES-D (NT, 15.2+/-8.1; OT, 5.8+/-5.5) and LSIA (NT, 9.9+/-2.8; OT, 14.4+/-2.9).
This study indicates that seated kyphosis and scoliosis develop early in individuals with tetraplegia and may not be progressive. No association was seen between pain and kyphosis or scoliosis in this relatively young sample (mean age of OT and NT combined, 34.8 years). Future research is needed to determine whether pain becomes a problem in individuals with significant kyphosis or scoliosis as they age.
No preview · Article · Jan 1999 · Archives of Physical Medicine and Rehabilitation
[Show abstract][Hide abstract] ABSTRACT: To address the issue of safely accessing and securing wheeled mobility devices in motor vehicles, more information characterizing current-production devices was needed. In a recent effort, frame characteristics of wheeled mobility devices were defined and a database developed for recording characteristics relevant to access and securement. A representative number of devices have been surveyed to measure key characteristics, and these measures have been recorded in the database. This paper details the development of the database and frame characterization scheme, the methods used to survey currently available wheeled mobility devices, and some descriptive statistics resulting from an analysis of the data. A discussion of how this information is being used in research aimed at developing technology and safety standards to ensure vehicle access and safe transportation, as well as other potential uses, is also included.
Full-text · Article · Feb 1997 · Assistive technology: the official journal of RESNA
[Show abstract][Hide abstract] ABSTRACT: The Americans with Disabilities Act (ADA) has led to an increase
in disabled travelers, many of whom are unable to transfer to a vehicle
seat and are required to use their wheelchair to fulfill this function.
ANSI/RESNA is currently developing a transportable wheelchair standard
which will identify design requirements and testing methods for
wheelchairs suitable for transport. Wheelchair manufacturers should
begin to modify their existing design criteria established for a normal
mobility function to design criteria appropriate for a transportation
function which may subject the wheelchair to large dynamic crash forces.
A thorough understanding of the crash environment and its effect on the
wheelchair is necessary to insure the safety of the wheelchair user. To
assist manufacturers in the design effort, this study uses mathematical
crash simulations to evaluate loads imposed upon a wheelchair when
subjected to a 48 kph/20 g frontal crash. Using a four-point belt
tiedown system to secure the wheelchair, securement point, seat, lap
belt anchor, and wheel loads are evaluated under three different
securement configurations. Results show that positioning of rear
securement points near the wheelchair center of gravity can serve as an
effective strategy for managing crash response and loadings on the
wheelchair. Force ranges for each of the evaluated parameters, derived
for a 50th percentile male using a simulated power wheelchair, are
provided for use as a preliminary guide when designing transportable
No preview · Article · Oct 1996 · IEEE Transactions on Rehabilitation Engineering
[Show abstract][Hide abstract] ABSTRACT: An investigation of the effect of the shoulder belt's upper anchor point location on crash protection during wheelchair transportation was conducted using a lumped parameter crash victim simulator. While varying the upper anchor point location in each of three directions, the occupant kinematics and injury criteria of the Hybrid III test dummy were determined. Through comparison of these parameters and their associated trends, it was determined that varying the location of the anchor point has a significant effect on the crash protection of the occupant.
Full-text · Article · Aug 1996 · The Journal of Rehabilitation Research and Development
[Show abstract][Hide abstract] ABSTRACT: In May 1991, approximately 40 world experts on technology and aging were invited to Directions '91 in Winnipeg, Canada. The focus of the 3-day seminar was on living environments for seniors and on the research and development of products to meet the needs of an aging society. The built environment--furnishings and appliances, self-care, and leisure and recreation--was targeted in both plenary and breakout sessions. This article highlights the key concerns and recommendations developed at Directions '91. The "universal design" concept is stressed, particularly as it relates to our need to rethink the design of the built environment and the products that are currently being used by seniors seeking independence and dignity in their daily living. Consideration is also given to the physiological changes that occur in the natural process of aging and how these changes need to be accommodated in products designed for the living environment.
No preview · Article · Oct 1994 · Experimental Aging Research
[Show abstract][Hide abstract] ABSTRACT: This presentation is intended to provide an overview of the basic principles of pressure sore causation and the procedures used for clinical management, as viewed from the assistive technology perspective.