Wheelchair accessibility: Descriptive survey of curb ramps in an urban area

Design and experimental validation of a new wheelchair seat stabilization system

PURPOSE

Seat tilting wheelchair features can increase the comfort and safety of the user. Although many power wheelchairs have tilting mechanisms, they are often designed with a specific wheelchair model in mind. In this study, a design process for seat tilting mechanisms that can be applied to most rear-wheel drive wheelchair models is developed.

METHODOLOGY

Equations were developed to describe the geometrical and load constraints that were used to size the electric actuator that powers the system and define its position. Finally, the equations were used to create the seat tilting mechanism of a prototype wheelchair, which was then tested.

RESULTS

The equations yielded coherent results which showed that advantageous actuator positions from a load minimization perspective usually require dimensions that cannot be found in commercial actuators. Also, there are positions in which the load increases exponentially, which should be avoided. The tests showed that the system was able to function properly on the prototype wheelchair and that the actuator position affected the time taken for the actuator to execute different parts of the tilting movement.

CONCLUSIONS

The design process presented here was successful and modelled by general equations that can be applied to most front-wheel drive wheelchairs. It presents a low-cost option for the design of seat tilting systems, which can increase their accessibility.

Disabled-by-design: effects of inaccessible urban public spaces on users of mobility assistive devices - a systematic review

PURPOSE

Despite the increase of users of Mobility Assistive Devices (MobAD), there has been a lack of accessibility in urban environments in many parts of the world. We present a systematic review of how the inaccessible design of public spaces affects quality-of-life - including aspects of health and safety, independence, and social participation - of MobAD users.

MATERIALS AND METHODS

We conducted a literature search in three databases (i.e., Scopus, Web of Science, and PubMed) and initially discovered 3980 publications. We analysed 48 peer-reviewed journal articles published in English from 2005 to 2021 and assessed their quality of evidence via the Mixed Methods Appraisal Tool.

RESULTS

Findings indicated a substantial number of inaccessible elements for MobAD users in public spaces. Pathway characteristics, boarding ramps, entrance features, confined spaces, and service surfaces were deemed to be the least accessible elements. These barriers had multifaceted effects on MobAD users' quality of life with aspects of physical health, mobility, and use of public transport being most affected.

CONCLUSIONS

Notwithstanding that the reviewed studies mostly ocused on wheelchair users residing in high-income countries, this review outlines the critical role of the design of the built environment as a factor of disablement for MobAD users. We conclude by highlighting a few recommendations for future research and practice, especially inclusive approaches and adaptive techniques to assist MobAD users with performing tasks in public spaces independently.Implications for RehabilitationUsers of Mobility Assistive Devices experience a lack of accessibility provisions in public open spaces and buildings internationally.Physical barriers in public spaces substantially diminish the health and safety, autonomy, and social participation of users of Mobility Assistive Devices.There is a definite need for the adoption of inclusive strategies and adaptive techniques in placemaking processes so that users of Mobility Assistive Devices can have equitable access to public spaces.

Evaluation of Power Wheelchair Dynamic Suspensions for Tip Prevention in Non-ADA Compliant Surfaces

OBJECTIVE

To evaluate the driving performance and usability of a mobility enhancement robot (MEBot) wheelchair with 2 innovative dynamic suspensions compared with commercial electric powered wheelchair (EPW) suspensions on non-American with Disabilities Act (ADA) compliant surfaces. The 2 dynamic suspensions used pneumatic actuators (PA) and electro-hydraulic with springs in series electrohydraulic and spring in series (EHAS).

DESIGN

Within-subjects cross-sectional study. Driving performance and usability were evaluated using quantitative measures and standardized tools, respectively.

SETTING

Laboratory settings that simulated common EPW outdoor driving tasks.

PARTICIPANTS

10 EPW users (5 women, 5 men) with an average age of 53.9±11.5 years and 21.2±16.3 years of EPW driving experience (N=10).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURE(S)

Seat angle peaks (stability), number of completed trials (effectiveness), Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST), and systemic usability scale (SUS).

RESULTS

MEBot with dynamic suspensions demonstrated significantly better stability (all P<.001) than EPW passive suspensions on non-ADA-compliant surfaces by reducing seat angle changes (safety). Also, MEBot with EHAS suspension significantly completed more trials over potholes compared with MEBot with PA suspension (P<.001) and EPW suspensions (P<.001). MEBot with EHAS had significantly better scores in terms of ease of adjustment (P=.016), durability (P=.031), and usability (P=.032) compared with MEBot with PA suspension on all surfaces. Physical assistance was required to navigate over potholes using MEBot with PA suspension and EPW suspensions. Also, participants reported similar responses regarding ease of use and satisfaction toward MEBot with EHAS suspension and EPW suspensions.

CONCLUSIONS

MEBot with dynamic suspensions improve safety and stability when navigating non-ADA-compliant surfaces compared with commercial EPW passive suspensions. Findings indicate MEBot readiness for further evaluation in real-world environments.

Manual wheelchair biomechanics while overcoming various environmental barriers: A systematic review

During manual wheelchair (MWC) locomotion, the user's upper limbs are subject to heavy stresses and fatigue because the upper body is permanently engaged to propel the MWC. These stresses and fatigue vary according to the environmental barriers encountered outdoors along a given path. This study aimed at conducting a systematic review of the literature assessing the biomechanics of MWC users crossing various situations, which represent physical environmental barriers. Through a systematic search on PubMed, 34 articles were selected and classified according to the investigated environmental barriers: slope; cross-slope; curb; and ground type. For each barrier, biomechanical parameters were divided into four categories: spatiotemporal parameters; kinematics; kinetics; and muscle activity. All results from the different studies were gathered, including numerical data, and assessed with respect to the methodology used in each study. This review sheds light on the fact that certain situations (cross-slopes and curbs) or parameters (kinematics) have scarcely been studied, and that a wider set of situations should be studied. Five recommendations were made at the end of this review process to standardize the procedure when reporting materials, methods, and results for the study of biomechanics of any environmental barrier encountered in MWC locomotion: (i) effectively reporting barriers' lengths, grades, or heights; (ii) striving for standardization or a report of the approach conditions of the barrier, such as velocity, especially on curbs; (iii) reporting the configuration of the used MWC, and if it was fitted to the subject's morphology; (iv) reporting rotation sequences for the expression of moments and kinematics, and when used, the definition of the musculoskeletal model; lastly (v) when possible, reporting measurement uncertainties and model reconstruction errors.

Analysis of Whole-Body Vibration Using Electric Powered Wheelchairs on Surface Transitions

Wheelchair users are exposed to whole-body vibration (WBV) when driving on sidewalks and in urban environments; however, there is limited literature on WBV exposure to power wheelchair users when driving during daily activities. Further, surface transitions (i.e., curb-ramps) provide wheelchair accessibility from street intersections to sidewalks; but these require a threshold for water drainage. This threshold may induce high WBV (i.e., root-mean-square and vibration-daily-value accelerations) when accessibility guidelines are not met. This study analyzed the WBV effects on power wheelchairs with passive suspension when driving over surfaces with different thresholds. Additionally, this study introduced a novel power wheelchair with active suspension to reduce WBV levels on surface transitions. Three trials were performed with a commercial power wheelchair with passive suspension, a novel power wheelchair with active suspension, and the novel power wheelchair without active suspension driving on surfaces with five different thresholds. Results show no WBV difference among EPWs across all surfaces. However, the vibration-dose-value increased with higher surface thresholds when using the passive suspension while the active suspension remained constant. Overall, the power wheelchair with active suspension offered similar WBV effects as the passive suspension. While significant vibration-dose-value differences were observed between surface thresholds, all EPWs maintained WBV values below the ISO 2631-1 health caution zone.

Automated Curb Recognition and Negotiation for Robotic Wheelchairs

Common electric powered wheelchairs cannot safely negotiate architectural barriers (i.e., curbs) which could injure the user and damage the wheelchair. Robotic wheelchairs have been developed to address this issue; however, proper alignment performed by the user is needed prior to negotiating curbs. Users with physical and/or sensory impairments may find it challenging to negotiate such barriers. Hence, a Curb Recognition and Negotiation (CRN) system was developed to increase user's speed and safety when negotiating a curb. This article describes the CRN system which combines an existing curb negotiation application of a mobility enhancement robot (MEBot) and a plane extraction algorithm called Polylidar3D to recognize curb characteristics and automatically approach and negotiate curbs. The accuracy and reliability of the CRN system were evaluated to detect an engineered curb with known height and 15 starting positions in controlled conditions. The CRN system successfully recognized curbs at 14 out of 15 starting positions and correctly determined the height and distance for the MEBot to travel towards the curb. While the MEBot curb alignment was 1.5 ± 4.4°, the curb ascending was executed safely. The findings provide support for the implementation of a robotic wheelchair to increase speed and reduce human error when negotiating curbs and improve accessibility.

Quantifying Mobility Scooter Performance in Winter Environments

OBJECTIVES

To quantify mobility scooter performance when traversing snow, ice, and concrete in cold temperatures and to explore possible performance improvements with scooter winter tires.

DESIGN

Cross-sectional.

SETTING

Hospital-based research institute.

PARTICIPANTS

Two drivers (50 and 100 kg) tested 8 scooter models (N=8). Two mobility scooters were used for winter tire testing.

INTERVENTIONS

Scooters were tested on 3 different conditions in a random sequence (concrete, 2.5-cm depth snow, bare ice). Ramp ascent and descent, as well as right-angle cornering up to a maximum of 10° slopes on winter conditions, were observed. Winter tire testing used the same slopes with 2 scooters on bare and melting ice surfaces.

MAIN OUTCOME MEASURES

Maximum achievable angle (MAA) and tire traction loss for ramp ascent and descent performance. The ability to steer around a corner on the ramp.

RESULTS

All scooters underperformed in winter conditions, specifically when traversing snow- and ice-covered slopes (χ² [2, N=8]=13.87-15.55, P<.001) and corners (χ² [2, N=8]=12.25, P<.01). Half of the scooters we tested were unable to climb a 1:12 grade (4.8°) snow-covered slope without losing traction. All but 1 failed to ascend an ice-covered 1:12 grade (4.8°) slope. Performance was even more unsatisfactory for the forward downslopes on both snow and ice. Winter tires enhanced the MAA, permitting 1:12 (4.8°) slope ascent on ice.

CONCLUSIONS

Mobility scooters need to be designed with winter months in mind. Our findings showed that Americans with Disabilities Act-compliant built environments, such as curb ramps that conform to a 1:12 (4.8°) slope, become treacherous or impassible to mobility scooter users when covered in ice or snow. Scooter manufacturers should consider providing winter tires as optional accessories in regions that experience ice and snow accumulation. Additional testing/standards need to be established to evaluate winter mobility scooter performance further.

Understanding urban accessibility: A community-engaged pilot study of entrance features

The accessibility of the built environment is an equity issue. Accessibility standards for buildings exist, but often apply to new buildings or major renovations. This renders historic neighborhoods inaccessible. Accessibility standards and related assessments rarely consider the experiences and priorities of people who experience disability. Partnered with local government and an accessibility advisory committee, we conducted a pilot study of urban accessibility in Edmonton Edmon, Alberta, Canada. We measured four indicators of entranceway accessibility along a popular, central commercial corridor and mapped the data with building age using QGIS. We found significant accessibility barriers.

Evaluation of the Biomechanical Parameters of Human-Wheelchair Systems during Ramp Climbing with the Use of a Manual Wheelchair with Anti-Rollback Devices

Purpose: The main purpose of the research conducted was the analysis of kinematic and biomechanical parameters measured during manual wheelchair ramp-climbing with the use of the anti-rollback system and the comparison of the values tested with the manual wheelchair climbing the same ramp but without any modifications. The paper presents a quantitative assessment relating to the qualitative research of the anti-rollback system performed by another research team. Method and materials: The article presents the measurement results of the wheelchair motion kinematics and the activity of four upper limb muscles for eight subjects climbing a 4.58° ramp. Each subject propelled the wheelchair both with and without the anti-rollback system. The kinematic parameters were measured by means of two incremental encoders with the resolution of 500 impulses per single revolution of the measurement wheel. Whereas, the muscle activity was measured by means of surface electromyography with the use of Noraxon Mini DTS apparatus equipped with four measurement channels. Results: The surface electromyography measurement indicated an increase in the muscle activity for all four muscles, during the use of the anti-rollback system. The increase was: 18.56% for deltoid muscle anterior, 12.37% for deltoid muscle posteriori, 13.0% for triceps brachii, and 15.44% for extensor carpi radialis longus. As far as the kinematics analysis is concerned, a decrease in the measured kinematic parameters was observed in most participants. The medium velocity of the propelling cycle decreased by 26%. The ratio of the generated power and the loss power in a single propelling cycle λ had decreased by 18%. The least decrease was recorded for the measurement of mechanical energy E and the propelling cycle duration time. For the total mechanical energy, the decrease level was 3%, and for the propelling cycle duration it was 1%. The research carried out did not demonstrate any impact of the anti-rollback system use on the push phase share in the entire propelling cycle.

Mobility and Participation of People With Disabilities Using Mobility Assistive Technologies: Protocol for a Mixed-Methods Study

Background

Many community-dwelling individuals living with a disability use mobility assistive technologies (MATs). MAT devices are generally beneficial for individuals with mobility impairments. However, less is known about the specific factors that may foster or deter mobility and community participation.

Objective

The purpose of this protocol is to describe the methodology for a study including three main objectives: (1) to understand the places people using MAT go and the things they do, (2) to identify perceived barriers and facilitators as well as users’ desired environmental modifications, and (3) to understand subjective and objective issues related to environmental accessibility.

Methods

A mixed-methods study was conducted in Vancouver and in Quebec City. Qualitative interviews were conducted to address all three objectives. In addition, Objective 1 was achieved through collection of global positioning system (GPS) data and activity diaries with 36 participants per site who represented six types of MAT users (ie, cane, walker, crutches, manual wheelchair, power wheelchair, and scooter). All participants were invited to take part in all aspects of data collection. PhotoVoice was used to address Objectives 2 and 3. Two environmental audits were used to address Objective 2. The Stakeholders’ Walkability/Wheelability Audit in Neighbourhood (SWAN) measured perceptions related to a variety of community environmental features associated with mobility and participation. A total of 24 participants were recruited to each study site for SWAN data collection. The Measure of Environmental Accessibility (MEA) was also used to objectively measure access to exterior and interior environments selected earlier in the project by the participants that could benefit from improvements.

Results

Funding for this study was obtained from the Social Sciences and Humanities Research Council of Canada. Approval was obtained from the University of British Columbia Research Ethics Board and the Centre intégré universitaire de santé et de services sociaux de la Capitale-Nationale Research Ethics Board. Regarding the MEA evaluations, 19 locations (ie, buildings and exterior spaces) where obstacles have been identified by the participants of the PhotoVoice focus groups have been evaluated in Quebec City and 20 locations have been identified in the Vancouver region by the participants of the community forums. Data collection for this project was completed in December 2018. Analysis and writing of manuscripts are underway.

Conclusions

The use of a variety of methods to gather data on participation and mobility will allow a more holistic consideration of factors influencing mobility with a MAT device. This study will provide objective information about the mobility of participants and identify barriers and facilitators that impact their mobility and community participation. Through the mixed-methods approach employed in this study, we will gain a subjective evaluation of the participants’ neighborhoods, including personally meaningful information on environmental features that influence participants' everyday mobility and participation. We will also gain an objective evaluation of particular obstacles that community users of MAT identify as significant barriers to their ability to access public environments. We anticipate that these findings will help to identify a broad spectrum of solutions to improve the mobility and community participation of MAT users.

International Registered Report Identifier (IRRID)

DERR1-10.2196/12089

Usability Evaluation of a Novel Robotic Power Wheelchair for Indoor and Outdoor Navigation

OBJECTIVE

To compare the Mobility Enhancement roBotic (MEBot) wheelchair's capabilities with commercial electric-powered wheelchairs (EPWs) by performing a systematic usability evaluation.

DESIGN

Usability in effectiveness, efficacy, and satisfaction was evaluated using quantitative measures. A semistructured interview was employed to gather feedback about the users' interaction with MEBot.

SETTING

Laboratory testing of EPW driving performance with 2 devices in a controlled setting simulating common EPW driving tasks.

PARTICIPANTS

A convenience sample of expert EPW users (N=12; 9 men, 3 women) with an average age of 54.7±10.9 years and 16.3± 8.1 years of EPW driving experience.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Powered mobility clinical driving assessment (PMCDA), Satisfaction Questionnaire, National Aeronautics and Space Administration's Task Load Index.

RESULTS

Participants were able to perform significantly higher number of tasks (P=.004), with significantly higher scores in both the adequacy-efficacy (P=.005) and the safety (P=.005) domains of the PMCDA while using MEBot over curbs and cross-slopes. However, participants reported significantly higher mental demand (P=.005) while using MEBot to navigate curbs and cross-slopes due to MEBot's complexity to perform its mobility applications which increased user's cognitive demands.

CONCLUSIONS

Overall, this usability evaluation demonstrated that MEBot is a promising EPW device to use indoors and outdoors with architectural barriers such as curbs and cross-slopes. Current design limitations were highlighted with recommendations for further improvement.

Mapping review of accessible pedestrian infrastructures for individuals with physical disabilities

BACKGROUND

Due to the ageing population and higher prevalence of individuals living with physical disabilities, there is a critical need for inclusive practices when designing accessible pedestrian infrastructures for ensuring social participation and equal opportunities.

PURPOSE

Summarize the physical characteristics of current pedestrian infrastructure design for individuals with physical disabilities (IPD - motor, visual and hearing) found in the scientific literature and assess its quality.

MATERIALS AND METHODS

A mapping review of the existing literature on pedestrian infrastructures specifically built for individuals with physical disabilities identifying measurable physical characteristics for their design was done using online databases (Urban Studies Abstracts, Geobase, PubMed, and Cairn and secondary research). Information about accessibility (physical characteristics) of existing pedestrian infrastructures was extracted. The quality of the evidence was assessed using the Guidelines for critical review form - Quantitative studies and Qualitative studies version 2.0 (SAGE Publications, Inc., Thousand Oaks, CA).

RESULTS

Of the 1131 articles identified, forty-one articles examined access to bus stops, curb ramps, lighting, pedestrian crossings, ramps, shared spaces, sidewalks and steps. Six articles reported on more than one physical disability. Quality scores were generally low (quantitative: 2-11/15 and qualitative: 1-22/23). Recommended design features differed for the same infrastructure.

CONCLUSIONS

While there were a fair number of articles (n = 41) documenting accessible design features of pedestrian infrastructures, the quality of the evidence was low. The review identified knowledge gaps. Although specific design solutions exist, they have not yet been tested among individuals with various or multiple types of physical disabilities to ensure access to pedestrian infrastructures by all. Implications for Rehabilitation Pedestrian infrastructures still pose problems to mobility, limiting social participation and quality of life outcomes for individuals with physical disabilities (motor, visual and hearing). The results of this mapping review show that few articles are concerned with the accessibility of pedestrian infrastructures for more than one type physical disability, which might lead to recommendations that are inadequate for individuals with differing disabilities, few recommendations have been compared, most studies have been performed in environments not representative of northern countries and their quality score was generally low. Health professionals and State Parties have a complementary expertise that should be put to use in the determination and implementation of best design solutions to ensure the respect of the needs of individuals with physical disabilities. This review can thus help them have an idea of what has already been done to identify what needs to be achieved to fill the gap of knowledge required to insure access for individuals with motor, visual as well as hearing disabilities. Rehabilitation profesionals should take part in the assessment of the proposed solutions as well as the development of new designs to fill knowledge gaps.

Wheelchair users’ perspectives on barriers in public spaces in Vienna: implications for the development of a barrier information system / Barrieren aus der Sicht von Rollstuhlnutzern/-innen im öffentlichen Raum in Wien: Implikationen für ein Barriere-Informationssystem

Background

Wheelchair users often encounter barriers reducing community mobility and participation in societal life. Information on barrier-free routes may improve mobility and therefore societal participation. In addition to technical prerequisites, a routing system will only be effective and used by the target group, if the development process is based on their perceptions and needs. The aim of the study was therefore to collect data on barriers from the viewpoint of wheelchair users in Vienna.

Methods

A multiprofessional team conducted three focus group discussions with 22 wheelchair users from Vienna (maximum variation sampling, wheelchair-bound individuals and assistants). Data were analyzed qualitatively using inductive and deductive content analysis. The International Classification of Functioning, Disability and Health, and the Occupational Performance Model (Australia) served as guiding frameworks during deductive data analysis. Barriers within the physical environment were further subcategorized.

Results

Barriers identified in all three groups could be assigned mainly to physical and socio-cultural environments. Most important physical barriers were ground conditions, curbstones and gradients. Other barriers were related to one’s own body, other people in the environment, and lack of information on structural conditions.

Discussion

Our results underline the benefit of participatory research and they demonstrate the complexity of barriers encountered by wheelchair users in the community. A routing system provides information to wheelchair users enabling them to avoid physical barriers in the community and to stakeholders enabling them to reduce and remove barriers in public spaces.

Impact of inaccessible spaces on community participation of people with mobility limitations in Zambia

BACKGROUND

The study investigated the perspective of people with mobility limitations (PWML) in Zambia, firstly of their accessibility to public buildings and spaces, and secondly of how their capacity to participate in a preferred lifestyle has been affected.

OBJECTIVES

Firstly to provide insight into the participation experiences of PWML in the social, cultural, economic, political and civic life areas and the relationship of these with disability in Zambia. Secondly to establish how the Zambian disability context shape the experiences of participation by PWML.

METHOD

A qualitative design was used to gather data from 75 PWML in five of the nine provinces of Zambia. Focus group discussions and personal interviews were used to examine the accessibility of the built environment and how this impacted on the whole family's participation experiences. The nominal group technique was utilised to rank inaccessible buildings and facilities which posed barriers to opportunities in life areas and how this interfered with the whole family's lifestyle.

RESULTS

Inaccessibility of education institutions, workplaces and spaces have contributed to reduced participation with negative implications for personal, family, social and economic aspects of the lives of participants. Government buildings, service buildings, and transportation were universally identified as most important but least accessible.

CONCLUSION

Zambians with mobility limitations have been disadvantaged in accessing services and facilities provided to the public, depriving them and their dependants of full and equitable life participation because of reduced economic capacity. This study will assist in informing government of the need to improve environmental access to enable equal rights for all citizens.

Gait algorithm of personal mobility vehicle for negotiating obstacles

PURPOSE

Personal mobility vehicles (PMVs) are under active development. Most PMVs are wheel-driven, a mode of transport notable for its efficiency. However, wheeled PMVs tend to have poor mobility against negotiating obstacles. The four-wheeled vehicle RT-Mover PType 3 has been developed featuring wheeled legs capable of leg motion. This allows the PMV to overcome uneven terrains, including a step approached at an angle, which ordinary wheelchairs cannot negotiate.

METHOD

This article discusses a gait algorithm in which a leg executes the necessary leg motion when optionally presented with obstacles on a road. In order to lift a wheel off the ground and perform a leg motion, the support wheels must be moved to support points to ensure that the vehicle remains stable on three wheels. When moving towards the target support point, a wheel may encounter another obstacle, and a response method for this case is also described.

RESULTS

To assess the gait algorithm, several configurations of obstacles were used for performance tests with a passenger. The capabilities of the PMV were demonstrated through experiments.

CONCLUSION

We proposed a novel gait algorithm for our PMV and realised the proposed motion pattern for PMV-based negotiating obstacles.

IMPLICATIONS FOR REHABILITATION

Our single-seat personal mobility vehicle, RT-Mover PType 3 features wheels attached on legs capable of performing leg motion, which allows the vehicle to traverse rough terrains in urban areas. We proposed a gait algorithm for RT-Mover PType 3 consisting of a series of leg motions in response to rough terrain. With this algorithm, the vehicle can traverse not only randomly placed obstacles, but also a step approached at an oblique angle, which conventional powered wheelchairs cannot navigate. Experiments with a passenger demonstrated the effectiveness of the proposed gait algorithm, suggesting that RT-Mover PType 3 can expand the mobility and range of activities of wheelchair users.