Electromagnetic Tracking of the Kinematics of Articulating Joints
Experimental Methods in Orthopaedic Biomechanics
URL with Digital Object Identifier
© 2017 Elsevier Inc. All rights reserved. The tracking of the kinematics of articulating joints during in vitro testing is of interest in determining the motion of healthy intact joints, as well as the changes after joint realignment, joint reconstruction, and/or soft tissue degeneration. Joint reconstruction can alter the kinematics of the joint, often resulting in a reduced range of motion and/or a significant change to soft tissue and interarticular loading. In vitro cadaveric testing, coupled with motion tracking of the bones of the joint, can provide insight into the changes when the native kinematics are compared to the reconstructed joint, permit the digitization of biologic structures using tracing techniques, and allow for the measurement of the relative motion of one structure (e.g., implanted or biological) with respect to another. The ability to track the motion of the bones associated with the articulating joint is of paramount importance in the study of joint motion. Numerous techniques have been employed, including goniometers, optical tracking systems, and electromagnetic tracking (ET) systems. However, ET offers the advantage of rapid real-time data acquisition in six degrees of freedom and eliminates line-of-sight issues common to optical techniques. Therefore, this chapter explains how to perform ET testing on articulating joints, as well as how to analyze, present, and interpret results.