Wheelchair Occupant Research Articles

Effect of travel direction and wheelchair position on the ease of a caregiver getting an occupied wheelchair across a soft surface: a randomized crossover trial

Purpose To test the hypotheses that, in comparison with pushing an occupied upright manual wheelchair forward, pulling backward on the push-handles improves the objective and subjective ease with which a caregiver can get the wheelchair across a soft surface (e.g., grass, mud, sand, gravel); and the ease with which a caregiver can get the wheelchair across a soft surface improves if the wheelchair is tipped back into the wheelie position. Methods We used a randomized crossover trial with within-participant comparisons to study 32 able-bodied pairs of simulated caregivers and wheelchair occupants. The caregiving participants moved an occupied manual wheelchair 5 m across a soft surface (7.5-cm-thick gym mats) under four conditions (upright-forward, upright-backward, wheelie-forward and wheelie-backward) in random order. The main outcome measure was time (to the nearest 0.1 s) and the main secondary measure was the ease of performance (5-point Likert scale). Results The upright-backward condition was the fastest (p < 0.05) and had the highest ease-of-performance scores. In the forward direction, there was no statistically significant difference in the time required between the upright and wheelie positions, but the wheelie position was considered easier. Conclusions Although further study is needed, our findings suggest that caregivers should pull rather than push occupied wheelchairs across soft surfaces. In the forward direction, caregivers may find the wheelie position easier than the upright condition. These techniques have the potential to both improve the effectiveness of and reduce injuries to caregivers. Clinical Trial Registration Number: NCT 04998539

The Effect of City Bus Maneuvers on Wheelchair Movement

A state-of-the-art four-point tiedown system, a prototype automatic docking system, and a prototype rear-facing wheelchair passenger station (RF-WPS) were installed in a large accessible transit vehicle (LATV). A manual wheelchair, powered wheelchair, and a three-wheeled scooter were used to test the securement performance of each wheelchair securement system during LATV normal driving, hard braking, and rapid turning maneuvers. All test wheelchairs were loaded with an ISO 7176 Part 11 compliant loader gage representing the weight of an average male wheelchair occupant. A tri-axial accelerometer measured vehicle acceleration during driving maneuvers, and a low-tech movement tracking system measured wheelchair movement during driving maneuvers. Results show that each wheelchair securement system limited wheelchair displacement to less than the 51-mm Americans with Disabilities Act (ADA) displacement limitation, and none of the securement systems showed visible signs of failure. Accelerations during LATV normal driving, hard braking, and rapid turning did not exceed 0.76 g.

The safety of wheelchair occupants in motor vehicles

Ensuring the free movement of disabled people, including the use of vehicles, is a fundamental right. Therefore, efforts should be made to draw up standards regulating both organisational and technical aspects related to the construction and testing of wheelchairs. The main purpose of the paper is a review the literature related to wheelchair transport safety and the current standards for wheelchair crash testing Wheelchair users must securely and safely attach their wheelchair to the vehicle when travelling. The most common methods include securing with a four-belt system or using docking systems. Docking systems allow the disabled person to restrain the wheelchair themselves. Their main limitation is the lack of standardisation. Issues related to in-vehicle wheelchair design and testing are mainly described in international ISO standards and, in the US, in ANSI standards. Not all wheelchairs are crash tested. Before using wheelchairs, it should be checked if they can be mounted in a car. An important issue is education of wheelchair users and their carers on proper wheelchair securing. Even when wheelchairs are effectively secured, occupants in wheelchairs could be seriously and fatally injured because of improperly used and positioned belt restraints.

Study of head-injury of handlebar type electric wheelchair occupant in side collision accident with automobile

Study of head-injury of handlebar type electric wheelchair occupant in side collision accident with automobile

Contrary to basic kinematic modelling, during tight turns, wheelchairs can slide sideways by non-negligible magnitudes: Collision risks may be increased

Small spaces make collision-free turns difficult for wheelchair users. Contrary to basic kinematic wheelchair modelling and not considered previously by engineers; when wheelchairs turn in small spaces, could lateral drift (sideways slipping) increase the risk of collisions with surrounding structures such as walls and doorways? An improved kinematic understanding can inform building design and therapeutic involvement with wheelchair use.Wheelchair lateral drift is investigated. Two experiments with assisted wheelchair use are reported. Weights represented wheelchair occupants. First, lateral drift was measured by motion capture (VICON): turns (n = 225) made by the experimenter, for six radii of curvature (0–613 mm) and four total-masses (81–142 kg). Second, lateral drift was measured by ruler: turns (n = 105) made by experienced wheelchair assistants (n = 22), for three radii of curvature (0, 306, and 800 mm), and self-selected maximum comfortable weights.Lateral drift away from centre of curvature occurred for all radii of curvature greater than 0 mm, and a maximum median lateral drift of 27 mm/rad occurred for 142 kg total mass with 459 mm radius of curvature. Lateral drift increased with mass (r² = 0.68 for 358 mm radius of curvature). During tight turns, lateral drift magnitude and direction is such that it can increase risks of collisions with surrounding structures.

Everyday use of power adjustable seat height (PASH) systems

ABSTRACT The objective of this study was to measure how, why, and where the power adjustable seat height (PASH) system of Quantum’s iLevel® wheelchairs were used. We instrumented iLevel® power wheelchairs for 24 adults to measure wheelchair occupancy, seat height, in-seat activity level, and bouts of mobility. Participants elevated their wheelchair 3.9 (4.4) (mean (SD)) times per day, including 1.0 (1.6) times per day past 9”. Twenty-nine percent of elevation events were transient, lasting < 1 min, while 42% of elevate events lasted >5 minutes. Sixty-seven percent of participants transferred while elevated at least once, typically from heights <5” or >9”, and 14 people changed their seat height between the transfer to and from the wheelchair. Twenty-three of 24 participants wheeled while elevated. Finally, in-seat activity level was greater while elevated. For many participants, the PASH system provided a functional benefit on a daily basis. Individuals elevated 4 times per day for activities including transfers, reach, gaze, or mobility. However, 14 participants did not elevate on at least 1 day. Further study is needed to identify the characteristics of people who will benefit most from a PASH system as well as to document the value associated with PASH system use.

Manufacturing custom-contoured wheelchair seating: A state-of-the-art review.

Custom-contoured wheelchair seating lowers risk of pressure injury and postural deterioration while custom-contoured wheelchair seating lowers risk of pressure injury and postural deterioration while increasing the stability and functional activity of the wheelchair occupant. Producing custom-contoured seating systems has historically been a labour-intensive process custom-contoured seating systems is historically labour-intensive. Evaluate the strengths and limitations of current manufacturing processes for custom-contoured wheelchair seating to suggest potential future manufacturing processes. Literature review of the state of the art. Research conducted through a literature review focused on the performance of different types of custom-contoured wheelchair seating products and processes over the last 40 years. Recent literature in orthotics and prosthetics was also consulted to assess future trends in seating. There are five main manufacturing processes currently used to produce custom-contoured wheelchair seating systems. No single process is yet suitable for all wheelchair users, but many manufacturers are transitioning to computer numerical controlled (CNC) milling to reduce manual labour. Adjustable micro-modular seating and moulded seat insert manufacturing are also prevalent and offer alternative seating to soft foam carving. There is a need in the custom wheelchair seating sector for processes that are fast, cost-effective, produce little to no material waste, and that can effectively maintain a comfortable seating micro-climate. Additive manufacturing may meet these criteria, but further evaluation is required. This review suggests that the custom-contoured wheelchair seating manufacturers are moving away from labour-intensive processes towards digital techniques, like CNC foam milling. Additive manufacturing is a potential new process that may reduce overall costs, the lead time in preparing seats and has the potential to better manage the seating micro-climate.

충돌모의(Sled) 시험에 의한 특별교통수단 휠체어 탑승자 상해에 관한 연구

충돌모의(Sled) 시험에 의한 특별교통수단 휠체어 탑승자 상해에 관한 연구

Power seat function usage and wheelchair discomfort for power wheelchair users

Objectives: To investigate correlations between power seat functions (PSFs) usage and wheelchair discomfort.Design: Quasi-experimental design: Time series design.Setting: In-home trial in participants’ home/community.Participants: Thirteen power wheelchair users who independently used power wheelchairs equipped with PSFs as their primary means of mobility.Main Outcome Measures: PSF usage variables include the frequency of performing repositioning and using PSFs (tilt, recline, legrests and seat elevation), wheelchair occupancy, and driving distance. The Tool for Assessing Wheelchair disComfort (TAWC) were used to evaluate general discomfort and discomfort intensity.Results: Spearman correlation coefficient showed that the frequency of using tilt, recline, and legrest is significantly correlated with discomfort intensity. Multiple regression analysis with backward stepwise indicated that these functions can explain 43.8% of the variance (R2 = .438, F(3,33) = 8.588, P < 0.01) in the discomfort intensity score. The best-first decision tree shows that the frequency of using the legrest function was the top node, followed by recline and tilt functions. The overall accuracy of prediction with ten-fold cross validation for discomfort intensity was 79.4%.Conclusions: For people who used power wheelchairs equipped with PSFs, correlation analysis and regression modeling provided evidence from the quantitative data that increasing the frequency of using PSFs may decrease wheelchair discomfort. Future studies should include interventions to encourage people to use their PSFs appropriately.

Health, Personal, and Environmental Predictors of Wheelchair-Use Confidence in Adult Wheelchair Users

There are no predictive models of wheelchair-use confidence. Therefore, clinicians and researchers are limited in their ability to screen for and identify wheelchair users who may be more prone to low wheelchair-use confidence and may benefit from clinical intervention. The purpose of this study was to identify health-related, personal, and environmental factors that predict perceived wheelchair-use confidence in community-dwelling adults who use manual wheelchairs. A cross-sectional study was conducted. Community-dwelling manual wheelchair users (N=124) were included in the study if they were ≥50 years of age, had ≥6 months of wheelchair use experience, and had no cognitive impairment. The Wheelchair Use Confidence Scale was used to assess wheelchair-use confidence. The sociodemographic information form, Functional Comorbidity Index, Seating Identification Tool, Interpersonal Support and Evaluation List, and Home and Community Environment Instrument captured the independent variables. Blocks of health, personal, and environmental variables were sequentially entered into the regression model. Five personal variables (age, standardized beta [β]=-0.18; sex, β=-0.26; daily hours of wheelchair occupancy, β=0.20; wheelchair-use training, β=0.20; and wheelchair-use assistance, β=-0.34) and one environmental variable (need for seating intervention, β=-0.18) were statistically significant predictors, explaining 44% of the confidence variance. The sample comprised volunteers and, therefore, may underrepresent or overrepresent particular groups within the population. The study's cross-sectional research design does not allow for conclusions to be made regarding causality. Older women who use wheelchairs and who require assistance with wheelchair use may have low wheelchair-use confidence. The same is true for individuals who have no formal wheelchair-use training, who are in need of a seating intervention, and who report few hours of daily wheelchair use. These wheelchair users may require clinical attention and benefit from intervention.

Kinematics and injury risk of a wheelchair occupant in a railway vehicle crash

This paper presents results of computer numerical modelling of a wheelchair occupant during a railway vehicle crash for the baseline wheelchair seating condition. The baseline condition (baseline securement case) refers to the current practice in the EU where the wheelchair occupant is provided with a designated wheelchair space. However, the wheelchair is not secured and the occupant is not restrained. A numerical model of a wheelchair and occupant in a railway vehicle were developed and solved using LS-DYNA3D. Validation was achieved using experimental results. A crash pulse of about 5 g was applied to the virtual crash test sled in line with the European Commission (EC) requirements. For all crash tests to assess the potential injury severity, a Hybrid III 50th percentile male anthropometric test device (ATD) was applied. The initial conditions, boundary conditions and material characteristics were obtained from human factors studies, experimental tests and literature.

Identifying Challenges to Securing Wheeled Mobility Devices Using Tiedowns and Occupant Restraint Systems From the User Perspective

OCCUPATIONAL APPLICATIONS Wheeled mobility device passengers rely upon bus operators for proper securement of the wheelchair tiedown and occupant restraint system during transit. Yet, wheeled mobility devices are rarely properly secured, and passengers are often unrestrained during transit. This study investigated the usability of wheelchair tiedown and occupant restraint systems aboard transit systems to identify challenges resulting in improper securement or non-use of the wheelchair tiedown and occupant restraint system system. The task demands and bus operator's functional limitations appeared mismatched, jeopardizing the wheeled mobility device user's safety during transit. The current findings suggest the need to incorporate the bus operator's role during subsequent design or redesign of the wheelchair tiedown and occupant restraint system task.TECHNICAL ABSTRACT Rationale: Public transportation buses are required to be equipped with wheelchair tiedowns and occupant restraint systems to ensure safe transit of wheeled mobility device users. Wheeled mobility device users rely upon bus operators for wheeled mobility device securement, yet proper wheelchair tiedown and occupant restraint system implementation is often not performed. Prior research efforts in wheelchair transportation safety have not considered the bus operator's physical health as a challenge to securing a wheeled mobility device passenger. Purpose: The current study characterized musculoskeletal pain and discomfort, along with functional limitations, among bus drivers in the context of assisting wheeled mobility device passengers. Findings from this study were then synthesized with a previously reported ergonomic analysis to provide a more comprehensive understanding of factors that may pose challenges to bus operators securing a wheeled mobility device passenger. Methods: Musculoskeletal pain and functional limitations were determined by self-reports using a customized and standardized questionnaire. Previously reported task demands were quantified by ergonomic analyses of the wheelchair tiedown and occupant restraint system task. Results: Eighty-three percent of the operators reported musculoskeletal pain/discomfort in at least one body region, and 60% reported experiencing pain across multiple regions of the body. The highest number of prevalent reports of pain and functional limitations identified by the operators were at the knees, low back, neck, and shoulders. Ergonomic analyses revealed higher demands for these same four body regions, suggesting limited ability of the operators to perform the wheelchair tiedown and occupant restraint system task properly. Conclusions: The mismatch between the wheelchair tiedown and occupant restraint system work-related factors and the bus operator's functional limitations may contribute to the observed improper securement. These findings suggest a redesign of the wheelchair tiedown and occupant restraint system is warranted, which should incorporate the role of bus operators during the process.

Energy cost of pushing a wheelchair on various gradients in young men

This study investigated the effects of pushing a wheelchair on the energy cost of walking (Cw; defined as the ratio of the steady-state oxygen consumption to the walking speed) and economical speed (ES) on the level and ±5% gradients. Eight pairs were formed from twelve young men to minimize variation in body weight between pushing and assisted participants. The State Trait Anxiety Inventory (STAI) test was conducted to evaluate wheelchair occupants' anxiety before and after each trial. The Cw values were significantly higher when pushing a wheelchair on the uphill gradient at more than 45 m/min. ES was significantly lower when pushing a wheelchair on the level (−8.5%) and uphill gradient (−9.1%), but not on the downhill gradient (−0.3%). Individual ES was also estimated using the concept of “Froude number”, and “estimated” ES was significantly correlated with “measured” ES even when pushing a wheelchair on the downhill gradient. The STAI score was not significantly increased except at 105 m/min, regardless of gradient. These results indicated that the fastest walking speed without an enhancement in wheelchair occupants' anxiety corresponds to ES when pushing a wheelchair with a seated occupant on all gradients, at least in young fit men. Relevance to industryThis study provides information on alterations in ES while pushing a wheelchair on different gradients, with the associated perspective of wheelchair occupants' anxiety. The results are useful for reducing energy expenditure and/or avoiding the early onset of fatigue in wheelchair assistants without increasing wheelchair occupants' anxiety.

Wheelchair Securement and Occupant Restraint System (WTORS) Practices in Public Transit Buses

The purpose of this study was to characterize wheelchair tiedown and occupant restraint system (WTORS) usage in public transit buses based on observations of wheelchair and scooter (wheeled mobility device: WhMD) passenger trips. A retrospective review of on-board video surveillance recordings of WhMD trips on fixed-route, large accessible transit vehicles (LATVs) was performed. Two hundred ninety-five video recordings were collected for review and analysis during the period June 2007–February 2009. Results showed that 73.6% of WhMDs were unsecured during transit. Complete use of all four tiedowns was observed more frequently for manual wheelchairs (14.9%) and power wheelchairs (5.5%), compared to scooters (0.0%), and this difference was significant (p = 0.013). Nonuse or misuse (lap belt use only) of the occupant restraint system occurred during 47.5% of WhMD trips. The most frequently observed (52.5%) use of the lap belt consisted of bus operators routing the lap belt around the WhMD seatback in an attempt to secure the WhMD. These findings support the need for development and implementation of WTORS with improved usability and/or WTORS that can be operated independently by WhMD passengers and improved WTORS training for bus operators.

Effects of ramp slope on usability when a wheelchair is propelled by attendant

Many wheelchair users are accompanied by an attendant, but most prior studies did not consider this fact. This study investigated effects of ramp slope on wheelchair velocity and subjective discomfort considering both the wheelchair occupant and the attendant while ascending with the occupant facing forward, descending with the occupant facing forward, and descending with the occupant facing backward. Forty (20 male, 20 female) participants were dividing into four groups: male – male (attendant – occupant), male – female, female – male, female – female. To evaluate the usability of the ramp, analysis considered the four levels of user group and five levels of the ramp slope (1:6, 1:8, 1:10, 1:12 and 1:14) as independent variables, and mean wheelchair velocity, attendants’ physical discomfort, and occupants’ psychological anxiety as dependent variables. Considering the opinions of both the attendant and the occupant, 1:12 was recommended as the appropriate ramp slope. Furthermore, when descending a ramp, the occupant should be able to look forward.

Design and Fabrication of a Motorized Prototype Tricycle for the Disable Persons

This project design is embodied on a motorized tricycle for disabled Persons. The tricycle was specifically designed to suit wheelchair occupants of healthy Upper torso with pelvic to foot restraint. It is also designed to suit a commonly available Wheel chair. The level of relationship between the disabled people in the society has highly being jeopardized; therefore this project was designed to correct the difficulties in mobility of the wheelchair users. The main aim of the project design is to ease mobility for the physically challenged and also provide adequate comfort they desire. Existing tricycles for the disables requires the disabled person to dismount from the wheelchair onto the tricycle. The motorized tricycle in this project is designed to overcome this problem by allowing the disabled person to wheel up or down his wheelchair onto or down the tricycle. This is achieved using a specially designed platform that allows the wheel chair to be wheeled up or down. The prototype of this tricycle has been fabricated. The anthropometrics data that need to be considered in the design of the platform and frame of the tricycle have been taken into consideration at the design stage of the tricycle.

Wheelchair occupant kinematics during a rail carriage crash

Over recent years, a number of legislative tools and codes of practice have been put in place to provide wheelchair users with greater access and freedom of using trains. However, much more is still needed to be done to improve the safety of wheelchair occupants (WOs) while on board. In the United Kingdom, under the Disability Discrimination Act, only approved dimensions are the minimum requirements for use of a wheelchair in a rail carriage. This paper seeks to provide an analysis of the experimental kinematics of a WO under frontal impact tests carried out using a 57 kg dummy subjected to a sudden stop generating a pulse of about 15 g, which is less than the ECE M1 vehicle category. However, this is more severe than the 5 g pulse that covers both the European Commission's TSI and prEN 15227 with regards to train crashes. Results of frontal impacts are presented where the resulting kinematic characteristics are used to assess the potential injury severity of the occupant. A loaded sled with a combined mass of about 200 kg was accelerated horizontally to 3.3 m/s and suddenly stopped using a rigid barrier to simulate the worst loading condition. Eight restraint scenarios are covered. These form the basis for making recommendations considering the safety of a WO during a crash of a rail carriage. The baseline scenario constitutes not securing the wheelchair and not restraining the occupant. This also represents the worst case for injury potential. The ideal scenario involves securing the wheelchair and restraining the occupant using a three-point occupant restraint system. The paper concludes by providing recommendations for seating configurations to improve the survivability of a WO during a crash in a railway vehicle.

Distinct tilting behaviours with power tilt-in-space systems

Purpose. To characterise the use of tilt-in-space systems and to form recommendations for tilt prescription and training based upon its use.Method. Wheelchair occupancy and seat position of 45 full-time power wheelchair users were monitored for 1–2 weeks using an accelerometer, occupancy switch and data logger. Demographics, pressure ulcer history, functional and physical presentations of their disability, and sensation were also documented.Results. Participants spent 12.1 h in their wheelchairs daily, with a median typical position of 8° (0°–47°). The median participant tilted every 27 min (0.1–16.6 tilts per occupancy hour). Pressure-relieving tilts (i.e. a tilt ≥30° for ≥1 min) were performed, on average, once every 10 h (0–2.2/h). Participants spent 19% of their seated time tilted past 15°. Seventeen participants utilised the tilt feature frequently and spent >20% of the time in multiple positions. The remaining participants sat in a single tilt range for >80% of the time.Conclusions. Given the limited pressure relief compliance, alternative approaches to pressure relief and improved training may be needed for some clients. Wheelchair design and prescriptions may also need to reflect participants' preferences for sitting in small and medium tilts and changing position frequently.

Applying basic principles of child passenger safety to improving transportation safety for children who travel while seated in wheelchairs

Occupant restraint systems are designed based on knowledge of crash dynamics and the application of proven occupant-protection principles. For ambulatory children or children who use wheelchairs but can transfer out of their wheelchair when traveling in motor vehicles, there is a range of child safety seats that comply with federal safety standards and that therefore offer high levels of crash protection. For children who remain seated in wheelchairs for travel, the use of wheelchairs and wheelchair tiedown and occupant restraint systems (WTORS) that comply with voluntary industry standards significantly enhances safety. Revisions to the initial versions of these standards will further improve safety for smaller children who travel seated in wheelchairs by requiring wheelchairs for children between 13 and 22 kg (18 and 50 lb) to provide a five-point, wheelchair-integrated crash-tested harness similar to that used in forward-facing child safety seats. While wheelchair and tiedown/restraint manufacturers, van modifiers, transportation personnel, clinicians, and others involved with children who use wheelchairs have clearly defined responsibilities relative to providing these children with safe transportation, parents and caregivers should be knowledgeable about best-practice in wheelchair transportation safety and should use this knowledge to advocate for the safest transportation possible.

Floor anchorage load and safety space for adult wheelchair users during a crash

Over the last 20 years in France as well as generally in Europe and also in North America, the integration of disabled people into society has become a more and more pressing issue. Work is in progress to increase the safety level of wheelchair occupants up to becoming equivalent to that of able-bodied road vehicles occupants. Present world practices are that wheelchair occupants who are unable to transfer to a vehicle seat for transportation remain in their wheelchair, which is secured to the vehicle floor using tie downs, and the occupant is restrained in the wheelchair. The aim of this paper was to perform a series of crash tests to make sure that the current standards are suitable to identify possible failures in safety in the restraint systems intended for wheelchair users. To date, there is no specific regulatory criterion related to floor anchorage for wheelchairs in vehicles during a crash. At a 48 km/h crash test, loads reached 30 kN on rear anchorage, and 13 kN on shoulder belt. Also the kinematics analysis of the wheelchair user during impact pointed out dimension of his safety space.