Three-dimensional data-tracking dynamic optimization simulations of human locomotion generated by direct collocation
Institution:
1. Delaware Rehabilitation Institute, University of Delaware, Newark, DE, United States;2. Department of Biomedical Engineering, University of Delaware Newark, DE, United States;3. Department of Mechanical Engineering, University of Delaware, Newark, DE, United States;1. POLCOMING Department, Information Engineering Unit, University of Sassari, Sassari, Italy;2. Dept. of Electronics and Telecommunications, Politecnico di Torino, Torino, Italy;3. Interuniversity Centre of Bioengineering of the Human Neuromusculoskeletal System, University of Rome “Foro Italico”, Rome, Italy;4. Life and Health Sciences, Aston University, Birmingham, United Kingdom;5. Department of Mechanical Engineering, University of Melbourne, Victoria, Australia;6. Laboratory of Movement Analysis and Measurement, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland;7. Laboratory of Simulation and Movement Modeling, Department of Kinesiology, University of Montreal, Montreal, Canada;8. Faculty of Health Sciences, University of Ottawa, Ottawa, Canada;9. Artanim Foundation, Medical Research Department, Geneva, Switzerland;10. Department of Electric, Electronic and Information Engineering “Guglielmo Marconi” – DEI, University of Bologna, Italy;11. Institute of Biomedical Engineering, National Taiwan University, Taiwan, ROC;12. Department of Electronic Engineering, Fu-Jen Catholic University, Taiwan, ROC;13. Department of Orthopaedic Surgery, School of Medicine, National Taiwan University, Taiwan, ROC;14. Department of Mechanical Engineering, Cleveland State University, Cleveland, OH, USA;15. Department of Movement, Human and Health Sciences, University of Rome “Foro Italico”, Rome, Italy;1. School of Human Kinetics, University of Ottawa, Canada;2. Department of Engineering, University of Ottawa, Canada;3. School of Rehabilitation Sciences, University of Ottawa, Canada;1. Department of Mechanical Engineering & Research Centre for Biomedical Engineering, Universitat Politècnica de Catalunya, Av. Diagonal, 647 08028 Barcelona, Spain;2. School of Medical Sciences and Health of Juiz de Fora, SUPREMA, Alameda Salvaterra, 200 - Salvaterra, 36033-003, Juiz de Fora, MG, Brazil;3. Biomedical Engineering Program, COPPE, Universidade Federal do Rio de Janeiro, Av. Pedro Calmon, 550 - Cidade Universitária, 21941-901, Rio de Janeiro, RJ, Brazil;1. Department of Kinesiology, University of Maryland, 2134A SPH Building, College Park, MD 20742, USA;2. Department of Kinesiology, University of Massachusetts, Amherst, MA, USA
Abstract:
The aim of this study was to perform full-body three-dimensional (3D) dynamic optimization simulations of human locomotion by driving a neuromusculoskeletal model toward in vivo measurements of body-segmental kinematics and ground reaction forces. Gait data were recorded from 5 healthy participants who walked at their preferred speeds and ran at 2 m/s. Participant-specific data-tracking dynamic optimization solutions were generated for one stride cycle using direct collocation in tandem with an OpenSim-MATLAB interface. The body was represented as a 12-segment, 21-degree-of-freedom skeleton actuated by 66 muscle-tendon units. Foot-ground interaction was simulated using six contact spheres under each foot. The dynamic optimization problem was to find the set of muscle excitations needed to reproduce 3D measurements of body-segmental motions and ground reaction forces while minimizing the time integral of muscle activations squared. Direct collocation took on average 2.7 ± 1.0 h and 2.2 ± 1.6 h of CPU time, respectively, to solve the optimization problems for walking and running. Model-computed kinematics and foot-ground forces were in good agreement with corresponding experimental data while the calculated muscle excitation patterns were consistent with measured EMG activity. The results demonstrate the feasibility of implementing direct collocation on a detailed neuromusculoskeletal model with foot-ground contact to accurately and efficiently generate 3D data-tracking dynamic optimization simulations of human locomotion. The proposed method offers a viable tool for creating feasible initial guesses needed to perform predictive simulations of movement using dynamic optimization theory. The source code for implementing the model and computational algorithm may be downloaded at http://simtk.org/home/datatracking.
