WHO guidelines refer to ISO standards for quality. The ISO has developed a series of standards for wheelchairs (Series 7176), wheelchair cushions (ISO 16840 Part 2), and postural support devices (ISO 16840 Part 3). ISO 7176 series tests for stability, performance, wheelchair dimensions, and durability along with strength, impact, and fatigue. ISO 16840 tests for wheelchair seating systems and postural support devices. All requirements in the ISO 7176 series may not reflect typical conditions in less-resourced settings, as some of the requirements were designed to simulate the conditions in city environments with smooth roads.
WHO recommends countries use ISO 7176 as baseline standards and develop additional quality testing standards based on local conditions.
WHO assistive product specifications recommend that manual wheelchairs must meet ISO 7176 series, EN 12183, or equivalent standards for stability, brakes, dimensions, and impact and fatigue strength. And, to confirm adherence to standards ensuring quality and safety, a dated and signed report from a third-party test lab is required.
In LMICs, wheelchairs face a wide variety of environmental conditions, such as uneven terrains, high temperatures and humidity that can affect the durability of the wheelchair such that its components can fail prematurely. In fact, castors are one component that commonly fails in such conditions. Additionally, wheelchair parts are not particularly easy to repair or replace in less-resourced environments even though ISO 7176 section 8 refers to wheelchair testing including static, impact and fatigue, only a subset of field castor failures is covered. ISWP Standards Working Group proposed castor durability testing to meet the need to improve design and products. A team of ISWP staff designed, implemented, and is currently using a Castor Testing Machine to test castors as part of ISWP projects at the University of Pittsburgh. 156
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