ABSTRACT
The ISO impact damping test characterizes wheelchair cushion abilities to reduce impact loading on tissues and to help maintain postural stability, reporting the number of rebounds greater than 10% of the peak impact acceleration and the ratio of the 2nd to 1st rebound. Based upon our analysis, 3 critical issues have been identified. 1) Impact magnitude should be part of the analysis. 2) Impact should be used instead rebound accelerations. 3) Oscillation from impact is not a simple 2nd order damped harmonic, instead several natural frequencies are embedded in the damped oscillation. In conclusion, ISO should utilize impact accelerations and more complex analysis to characterize the damping properties of wheelchair cushions.
Keywords:
seating, ISO, pressure ulcer, impact damping, wheelchair
Acknowledgments
This work was completed as part of the Mobility RERC, which is funded by the National Institute on Disability and Rehabilitation Research of the U.S. Department of Education under grant number H133E030035. The opinions contained in this manuscript are those of the grantee and do not necessarily reflect those of the U.S. Department of Education. The authors also thank Tobias Meyer for providing valuable assistance.
Author Contact Information
Stephen Sprigle, PhD, PT
MobilityRERC, Center for Assistive Technology & Environmental Access, Georgia Institute of Technology, Atlanta, Gerogia
Tel.: 404-894-4960
Email: stephen.sprigle@coa.gatech.edu
Bummo Chung, MS
MobilityRERC, Center for Assistive Technology & Environmental Access, Georgia Institute of Technology, Atlanta, Gerogia
Tobias Meyer, MS, Dipl.Ing.
MobilityRERC, Center for Assistive Technology & Environmental Access, Georgia Institute of Technology, Atlanta, Gerogia
Tel: 404-385-8522
Email: Tobias.Meyer@GaTech.edu