Real-time inverse kinematics and inverse dynamics for lower limb applications using OpenSim

TLDR

Real‑time estimation of joint angles and moments is valuable for clinical, sport, and rehabilitation settings, yet current real‑time kinematics and kinetics rely on approximate solutions or generic anatomical models. The authors present an OpenSim‑based real‑time system that solves inverse kinematics and dynamics without simplifications at 2000 fps with less than 31.5 ms delay. The system’s software architecture, sensitivity analyses to minimize delays and errors, and comparisons between offline and real‑time results are described. The system could strongly impact rehabilitation practices by enabling real‑time use of personalized musculoskeletal models.

Abstract

Real-time estimation of joint angles and moments can be used for rapid evaluation in clinical, sport, and rehabilitation contexts. However, real-time calculation of kinematics and kinetics is currently based on approximate solutions or generic anatomical models. We present a real-time system based on OpenSim solving inverse kinematics and dynamics without simplifications at 2000 frame per seconds with less than 31.5 ms of delay. We describe the software architecture, sensitivity analyses to minimise delays and errors, and compare offline and real-time results. This system has the potential to strongly impact current rehabilitation practices enabling the use of personalised musculoskeletal models in real-time.