Introduction

Inverse Kinematics (IK) and Inverse Dynamics (ID) are two of the most common workflows used in biomechanics as joint angles and moments can provide insight into coordination of a movement. Measurement and modeling errors both contribute to errors during ID called residuals, which are additional forces and torques needed to account for inconsistencies in the dynamics of the simulation when fitting both marker and external force data. In this tutorial, you will use tools in OpenSim and AddBiomechanics to analyze the sources of these errors and ways to improve ID results.

Objectives

After completing this example, you will be able to do the following:

• Process real-world data to calculate joint kinematics (IK) and joint moments (ID) during walking
• Quantify errors in IK and ID and understand acceptable errors
• Improve IK and ID results by adjusting the data and model
• Understand sources of IK and ID errors and characterize which changes improved results