Date of download: 10/30/2017 Copyright © ASME. All rights reserved. From: Simulating Acceleration From Stereophotogrammetry For Medical Device Design J Biomech Eng. 2009;131(6):061002-061002-9. doi:10.1115/1.3118771 Figure Legend: Frustum of cone used to model forearm. The distance between markers on the elbow specified the radius of the cone at the elbow, re. The radius at the wrist, rw, was defined similarly using wrist markers. The distance between the center of the elbow (midpoint of elbow markers) and the center of the wrist (midpoint of wrist markers) defined the length of the cone, L. The position and orientation of the VCF were then defined by these parameters plus two user-defined variables, l and θ.