Evaluation of titanium ultralight manual wheelchairs using ANSI/ RESNA standards.

Comfortable propulsion and support, light weight, and small dimensions are important features that help preserve upper-limb integrity of manual wheelchair users and improve accessibility. The titanium wheelchair is a product developed in response to these goals, but none of the test results of titanium wheelchairs had been disclosed before this study was performed. We hypothesized that these titanium wheelchairs would be in compliance with American National Standards Institute (ANSI)/Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) standards. We tested 12 ultralight titanium rigid-frame wheelchairs (4 models) using ANSI/RESNA testing procedures and compared the test results with previously tested ultralight and lightweight aluminum wheelchairs. All wheelchairs passed the forward braking effectiveness test, but eight wheelchairs tipped backward before inclining to 7 degrees in the rearward braking effectiveness test. All wheelchairs passed the impact strength tests, but six wheelchairs failed in the static strength tests. Three wheelchairs successfully completed the fatigue tests, but the remaining wheelchairs failed prematurely. This group of titanium wheelchairs had less equivalent cycles and value than the ultralight aluminum wheelchairs that were tested in a previous study. The failure modes revealed important design issues of each model. Our results suggest that manufacturers may need to perform more careful analyses before commercializing new products.