A system for measurement and calibration of nonorthogonal joints and limbs in humans.

Human limbs are a multilinked system in which the revolute joints are not orthogonal to the limb segments or to each other. The standard method for movements of multilinked systems is the Denavit-Hartenberg (DH) representation, which is useful for orthogonal systems. When applied to non-orthogonal systems, the DH representation projects the reference frames outside of the limb segments. Computer graphics techniques move arrays of points in bodies that move about arbitrary revolute joints. This computational model has been modified to calculate both position (X, Y, Z) and orientation (yaw, pitch, and roll) of limbs and their individual segments. This method allows a simplified representation for the kinematics of animal limbs.