Objective: To evaluate ultralight folding manual wheelchairs UFMWs in order to produce comparative data on their strength, durability, stability and cost benefit, and to determine progress of wheelchairs by comparing these results to results of past studies.Design: Engineering testing using American National Standards Institute ANSI and Rehabilitation Engineering and Assistive Technology Society of North America RESNA standards.Setting: Laboratory testing of UFMW stability, and static, impact and fatigue strength performance with three devices using ANSI RESNA standardized tests.Participants: The three wheelchair models were the TiLite Aero X Permobil, Lebanon, TN , Sunrise Medical Quickie 2 Fresno, CA and Ki Mobility Catalyst 5 Stevens Point, WI .Interventions: ANSI RESNA standardized tests.Main outcome measures: Mass and critical measurements, static stability, static strength, impact strength, fatigue strength and cost analysis.Results: The ultralight folding wheelchairs continued to outperform their lightweight and rigid framed counterparts. ...