ISO 16840-13:2021

This document specifies apparatus, test methods, and disclosure requirements for determination of lateral stability properties of wheelchair seat cushions by measuring the response from the cushion to a shift in the centre of mass of the load on the cushion. It provides a method of determining changes in a particular physical and mechanical property of the cushion. It does not provide information specific to cushion performance for a particular individual user. It does not provide information related to anterior-posterior stability, nor to stability contributions from cushion edges. NOTE 1 Test conditions simulate a symmetric anatomy. NOTE 2 Loads are intended to represent those seen under the pelvis of a 40th to 60th percentile wheelchair user. This document is applicable to cushions used in situations other than a wheelchair.