Evaluating additive manufacturing for the production of custom head supports: A comparison against a commercial head support under static loading conditions

The provision of wheelchair seating accessories, such as head supports, is often limited to the use of commercial products. Additive manufacturing has the potential to produce custom seating components, but there are very few examples of published work. This article reports a method of utilising 3D scanning, computer-aided design and additive manufacturing for the fabrication of a custom head support for a wheelchair. Three custom head supports, of the same shape, were manufactured in nylon using a continuous filament fabrication machine. The custom head supports were tested against an equivalent and widely used commercial head support using ISO 16840-3:2014. The head supports were statically loaded in two configurations, one modelling a posterior force on the inner rear surface and the other modelling a lateral force on the side. The posterior force resulted in failure of the supporting bracketry before the custom head support. A similar magnitude of forces was applied laterally for the custom and commercial head support. When the load was removed, the custom recovered to its original shape while the commercial sustained plastic deformation. The addition of a joint in the head support increased the maximum displacement, 128.6 mm compared to 71.7 mm, and the use of carbon fibre resulted in the head support sustaining a higher force at larger displacements, increase in 30 N. Based on the deformation and recovery characteristics, the results indicate that additive manufacturing could be an appropriate method to produce lighter weight, highly customised, cost-effective and safe head supports for wheelchair users.