Essential wheelchair features for LMICs

An ‘appropriate wheelchair’ as defined by WHO is a wheelchair that:

WHO emphasizes that inappropriate wheelchairs can lead to poor outcomes for wheelchair users, including decreased health and mobility participation barriers, wheelchair breakdown resulting in disruption in use, and/or development of secondary complications – which in cases of people with spinal cord injuries and similar conditions can cause premature death.

WHO guidance on manual wheelchairs design for low-resourced settings154 emphasizes the following:

Table 50: WHO assistive product specification for manual active-use wheelchair

Active Urban Wheelchair Active Dual-Terrain Wheelchair Active Rough Terrain Wheelchair
User

Child or adult with basic, intermediate or advanced posture support needs

Primarily for people who self-propel, but also for people who need assistance

Child or adult with basic, intermediate or advanced posture support needs

Primarily for users who self-propel, but also for users who need assistance

Child or adult with basic, intermediate and advanced posture support needs to self-propel in rough outdoor terrain
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Active Urban Wheelchair Active Dual-Terrain Wheelchair Active Rough Terrain Wheelchair
User (continued)

For use in urban, indoor and outdoor environments

People with advanced mobility skills may also use this wheelchair for short distances on uneven terrain

For use in indoor and outdoor uneven urban, peri- urban and rural environments

Offers better outdoor mobility for users who do not have advanced wheelchair mobility skills

Also users who need assistance (excluding lever-propelled wheelchairs)
Specific Characteristic

Wheelchair with folding or rigid frame, three or four wheels with large rear wheels, seat and backrest, armrests and footrests

Overall length and wheelbase are similar to or shorter than transport wheelchair with large rear wheels

Rear wheels and front castors appropriate for urban indoor and outdoor use

Wheelchair with folding or rigid frame, three or four wheels with large rear wheels, seat and backrest, armrests and footrests

Footrests positioned in line or behind front castors

Longer wheelbase and shorter or similar overall length than transport wheelchair with large rear wheels

Rear wheels and front castors appropriate for indoor and outdoor mixed terrain

Wheelchair with folding or rigid frame; three, four or more wheels, with two larger drive wheels; seat and backrest; and footrests behind front castors

May be lever- propelled

Similar or longer wheelbase than dual- terrain wheelchair; larger overall length than transport wheelchair with large rear wheels

Low centre of gravity to ensure stability

Rear wheels and castors appropriate for outdoor rough terrain

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Active Urban Wheelchair Active Dual-Terrain Wheelchair Active Rough Terrain Wheelchair
Requirements for standard configuration
Frame
  • Frame with mechanism(s) to fold or dismantle
  • Push-handles can be integrated into frame, supplied as add-on components, or omitted if not required
  • Backrest or back posts with adjustable height or supplied with range of back posts with fixed height
  • Backrest contouring options, such as tension-adjustable backrest or rigid backrest that can be adjusted independently from back posts or with forward and backward and angle adjustment, including separate padded cover; can be mounted at different heights on back posts; quick- release mechanism to allow folding
  • Frame with mechanism(s) to fold or dismantle
  • Push-handles can be integrated into frame, supplied as add- on component, or omitted if not required
  • Backrest or back-posts with adjustable height or supplied with range of back- posts with fixed height
  • Backrest contouring options, such as tension-adjustable backrest or rigid backrest that can be adjusted independently from back-posts or with forward and backward and angle adjustment, including separate padded cover; can be mounted at different heights on back posts; quick-release mechanism to allow folding
  • Frame with mechanism(s) to fold or dismantle
  • Push-handles can be integrated into frame, supplied as an add-on component or omitted
  • Integrated stability options for feet
  • Backrest or back-posts with adjustable height or supplied with range of back-posts with fixed height
  • Backrest contouring options, such as tension-adjustable backrest or rigid backrest that can be adjusted independently from back-posts or with forward and backward and angle adjustment, including separate padded cover; can be mounted at different heights on back- posts; quick- release mechanism to be removed to allow folding
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Active Urban Wheelchair Active Dual-Terrain Wheelchair Active Rough Terrain Wheelchair
Frame (continued)
  • Footrests with adjustable height available in at least two adjustment ranges on all sizes of wheelchair to accommodate people with shorter and longer legs
  • Two flip-up, swing- away or removable footrests on folding frame
  • Optional – armrests and clothing guards with minimal profile
  • Footrests with adjustable height; available in at least two adjustment ranges on all sizes of wheelchair to accommodate people with shorter and longer legs
  • Two flip-up, swing- away or removable footrests on folding frames
  • Optional: armrests and clothing guards with minimal profile
  • Footrests with adjustable height; available in at least two adjustment ranges on all sizes of wheelchair to accommodate people with shorter and longer legs
  • Two flip-up, swing- away or removable footrests on folding frames
  • Optional: armrests and clothing guards with minimal profile
Frame Size Range
  • Seat width appropriate for profile of users; includes child, adult and bariatric sizes with 25–50 mm increments
  • Seat depth adjustable or with option for seat extension or supplied with range of seat frame depth options
  • Seat width appropriate for profile of users; includes child, adult and bariatric sizes with 25–50 mm increments
  • Seat depth adjustable or with option for seat extension or supplied with range of seat depth options
  • Seat width appropriate for profile of users; includes child, adult and bariatric sizes with 25–50 mm increments
  • Seat depth adjustable or with option for seat extension or supplied with range of frame seat depth options
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Active Urban Wheelchair Active Dual-Terrain Wheelchair Active Rough Terrain Wheelchair
Rear Wheels

Quick-release or removable without tools Optional camber with maximum 3 ° (off from vertical) • diameter e.g. 508–660 mm Width e.g. 25–35 mm

Puncture-proof or pneumatic rear tyres

Quick-release or removable without tools for rigid frames Quick-release or removable without tools for folding frames is optional Camber ranges from 0° (rear wheel perpendicular to ground) to 1−3 ° (off from vertical) Diameter, appropriate for size of wheelchair, e.g. 508–660 mm Width e.g. 35−44 mm

Puncture-proof or pneumatic rear tyres

With push-rims or lever-propelled Quick-release or removable without tools for rigid frames for transport; optional for wheelchairs with folding frame Camber minimum 3° (off from vertical) for stability Diameter, appropriate for size and design of wheelchair, e.g. 610–711 mm Width e.g. 35−44 mm Wider or larger- tread tyres

Puncture-proof or pneumatic rear tyres

Front Castors

Diameter e.g. 127– 203 mm Width e.g. 13–50 mm

Puncture-proof or pneumatic front castors

Diameter and width variable: e.g. 203 x 50 mm, 102 x 76 mm

Puncture-proof or pneumatic front castors

Diameter e.g. Over 203 mm Width e.g. Over 50 mm

Puncture-proof or pneumatic front castors

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Active Urban Wheelchair Active Dual-Terrain Wheelchair Active Rough Terrain Wheelchair
Frame and Wheel Adjustments
  • Rear wheel or seat unit relative to wheelbase can be horizontally adjusted using tools
  • Front and rear seat- to-floor heights can be adjusted through wheel or frame adjustments or through range of different fixed- frame seat heights to optimize fit for foot propelling on folding-frame wheelchairs
  • Rear wheel or seat unit relative to wheelbase can be adjusted horizontally using tools
  • Front and rear seat-to-floor heights can be adjusted through wheel or frame adjustments or supplied through range of different fixed-frame seat heights
  • Rear wheel axle or seat unit relative to wheelbase can be horizontally adjusted using tools
  • Front and rear seat- to-floor heights can be adjusted through wheel or frame adjustments or supplied through range of different fixed-frame seat heights
Rear and front wheels (lever propelling) Information not available Information not available
  • Size and width of front and rear wheels appropriate for rough terrain and wheelchair design
  • Three or multiple wheels
  • Puncture-proof or pneumatic wheels
Postural Support for intermediate- and advanced- level services

Wheel or frame adjustments using tools to change seat angle; minimum adjustment range 10–15 degrees; if seat angle is independently adjustable, seat-to- backrest angle must also be adjustable Backrest to seat angle (recline) adjustments with or without use of tools; minimum adjustment range 10–15 degrees Mechanism or adjustment options are available to maintain backwards stability with maximum combined seat and backrest configuration adjustments

Additional requirements on adjustability for postural support for intermediate- and advanced-level services:

Removable backrest upholstery with back-post capabilities to accept third- party backrests Armrests with adjustable height, and short and full-length arm pads; design and function of armrests should not restrict fitting of third-party backrests

Source: WHO Assistive Product Specification https://www.who.int/publications-detail-redirect/9789240020283

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Table 51: WHO general seating and postural support guidelines

WHO general seating and postural support guidelines

All wheelchairs provide seating and postural support as well as mobility. Good postural support is critical especially for users who have an unstable spine or are likely to develop secondary deformities. A wheelchair and cushion should meet the seating and postural support requirements of the user(s). This includes the size of the wheelchair, the type of cushion, and the adjustability and ergonomic factors of the wheelchair

All wheelchairs should be provided with a cushion that is appropriate to manage the user’s risk of developing pressure sores. A wheelchair should be evaluated based on the seating and postural support measures, and the results should be available to the users and purchasers. Cushions should be evaluated and rated based on their ability to provide comfort, pressure relief and postural support, and the results should be available to the users and purchasers.

A higher level of adjustability or custom adaptations may be needed for users who require more complex postural support.

Overall, WHO recommends that wheelchairs and cushions be evaluated based on the seating and postural support performance measures, and the results be available to the users and purchasers. The areas in which a wheelchair and cushion should be evaluated or reported on are 1. seating dimensions and adjustability, and 2. cushion types and characteristics. Seating dimensions and cushion characteristics tests and reporting techniques are covered in ISO standards 7176-7 and 16840-2.

Seating and Postural Support Elements
Seat bases
  • Wheelchair seats should have a continuous surface with no breaks that might cut or pinch the user’s skin.
  • The angle of the seat, in relation to the horizontal, should be between 0 and 12 degrees (with the front portion of the seat higher than the rear portion of the seat)
  • The seat must be level from side to side
  • A range of seat sizes should be available to fit a range of body sizes
  • Sling seats should be designed with materials that do not stretch over time from the weight of the user
  • Sling seats and solid seats should be used with cushions designed or modified for use on a sling seat and solid seat, respectively
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WHO general seating and postural support guidelines
Cushions

The cushion should be removable from the wheelchair. The cushion should be easy to clean using basic materials such as soap and water. The cushion should be an appropriate size to fit on the seat base. Correct cushion use and the way in which it should be placed on the wheelchair seat (which side is up, and which is the front of the seat) should be clearly indicated. Information on how the cushion should be used and maintained should be available.

Pressure relief cushions:

A pressure relief cushion should reduce pressures at the high- risk areas for pressure sore development (commonly at ischial tuberosities and sacrum) A pressure relief cushion should minimize the build-up of moisture between the cushion and the user’s skin Information should be available on how to use the cushion, how to maintain it, the expected life of the cushion, when to replace the cushion or parts of it, and any particular risks when using the cushion The cushion and cushion cover material should not cause high pressures, thereby reducing the effectiveness of the cushion in distributing pressure over the seat surface Pressure relief cushions should maintain their pressure relief properties in the climates where the cushion is expected to be used

Backrests
  • The angle between the seat and the backrest (seat to back angle) should be between 80 and 100 degrees
  • Different backrest heights should be available
  • The backrest should support the normal curvature of the spine. The middle of the back should be able to rest further back than the back of the pelvis
Footrests
  • Sufficient ground clearance needs to be maintained to prevent the footrest hitting obstacles or catching and tipping the wheelchair on uneven ground
  • The height of the footrest should be adjustable
  • Footrests need to be long or wide enough to support the foot but, at the same time, should not create difficulty while folding or moving around
Armrests
  • Armrests should be removable, folding or low-profile for easy transferral in and out of the wheelchair
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WHO general seating and postural support guidelines
Rear Wheels
  • The position of the rear wheel should allow the user to have a good push stroke and provide the necessary stability

Source: WHO Guidelines on the provision of manual wheelchairs in less resourced settings (2008) https://iris.who. int/bitstream/handle/10665/43960/9789241547482_eng.pdf?sequence=1

Many international organizations such as the International Society of Wheelchair Professionals (ISWP) 155, a global, multidisciplinary, nongovernmental organization aiming to improve the quality of life for people who may benefit from mobility devices, serve as global resources to coordinate and improve wheelchair service standards and provision. ISWP has published design considerations for wheelchairs used in adverse conditions.

Per ISWP guidance, “a wheelchair interacts with and is affected by both the environment and the user.” Hence a wheelchair design needs to consider both the user and its environment. Design considerations should consider the user: A wheelchair design needs to account for who they are designing the wheelchair for. Wheelchairs for permanent use are not generic devices that can be utilized by anyone needing a wheelchair. Wheelchair users vary by:

Design choices should also consider users’ environment and transportation.

Implications on reliability related to the environment:

How will the wheelchair be transported:

In the rehabilitation of individuals with walking limitations, it is crucial to provide a wheelchair that not only fits correctly but also aligns with the user’s physical, functional, and environmental needs. This requires an approach that responds to individual’s unique requirements and promotes the provision of wheelchairs through service provision that assesses individual user needs, assist in selecting an appropriate wheelchair, train users and caregivers, and provide ongoing support and referral to other services where appropriate.

In terms of service delivery, WHO recommends wheelchair provision through a service model, which provides, at a minimum: individual assessment and selection; preparation and fitting of the wheelchair for the wheelchair user; information and training for wheelchair users to maximize their safe and efficient use and care of the product; and follow-up to ensure the wheelchair continues to meet the user’s needs.

Figure V: Summary of wheelchair service steps recommended by WHO

1. Select 2. Fit 3. Train 4. Follow up
The wheelchair user’s specific needs and preferences are defined through an individual assessment, to select the most appropriate wheelchair(s) for them. The wheelchair, wheelchair cushion, postural support devices and any other accessories are prepared and fitted for the wheelchair user. The wheelchair user, along with those who will assist them, takes part in task- specific training in how to use and care for their wheelchair. Follow up is offered to all users, for as long as they require a wheelchair, with the frequency based on their individual needs.
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