CENTER OF PRESSURE AND JOINT TORQUE ESTIMATION FOR SINGLE LEG SLACKLINE BALANCING USING MODEL-BASED OPTIMIZATION

Being similar to tightrope walking, slacklining has become very popular among athletes and physiotherapists to practice and improve balancing capabilities. For flat ground static balance the center of pressure is often used to quantify how stable a subject is. In this work we present a method to reconstruct the center of pressure and the joint torques from pure motion capture data for motions that don’t allow for force plate measurements. We demonstrate the application to a subject balancing on a slackline. We create a subject-specific 3D-model and perform a least-squares fit to the recorded motion by formulation and solution of an optimal control problem. From the resulting forces we construct the center of pressure dynamics and quantify how stable the subject is on a slackline. The joint torques allow for further insight into the balancing strategies applied.