Comparison of fatigue life for 3 types of manual wheelchairs

Objectives: To examine 3 types of manual wheelchairs-ultralight wheelchairs (UWs), lightweight wheelchairs (LWs), and depot wheelchairs (DWs)-and to compare the fatigue life between the wheelchair types. Design: A database of different manual wheelchairs tested according to the International Organization for Standardization (ISO). Fatigue life was determined by using standards that define methods accepted internationally using double-drum and curb-drop testing equipment. Setting: A rehabilitation engineering center. Specimens: Sixty-one manual wheelchairs: 25 DWs, 22 UWs, and 14 LWs. Main Outcome Measures: Wheelchairs were examined for differences in fatigue life based on equivalent cycles. Unique survival curves were fit and compared for each wheelchair type. Results: The UWs lasted the longest, with a mean of 309,362 equivalent cycles. The DWs faired the worst, with a mean of 117,210 equivalent cycles. The Kaplan-Meier survival curves Were significantly different (p < .001). with the UWs having the longest fatigue life. Conclusion: Fatigue life for UWs is significantly greater (p < .05) than LWs and DWs, indicating wheelchairs differ in durability.