Innovations: Spring 2009 Annual Report of the Kessler Medical Rehabilitation, Research, and Education Center

URL:

http://www.kesslerfoundation.org/research/pdf/innovations/Innovations_8_1.pdf

Abstract:

A model is a mathematical representation of a system being studied, whether it is a drug delivery model, an injury progression model or a biomechanical model like the ones used in REAL. The different modeling programs the lab uses are able to generate biomechanical models of human motion, with varying levels of sophistication. These models range from simple to elaborate, depending on the number and types of input variables utilized, as well as on what question is being answered. The two programs REAL uses to model biomechanics of human movement are Matlab/Simulink and LifeMOD™.

Matlab/Simulink is used to model how research participants react when standing on a platform oscillating in the forward/backward direction. By specifying the properties of the model’s body segments and joints, the observed movement patterns that research participants exhibit can be recreated. Individual properties can be altered to examine how injuries and weaknesses affect the movement pattern or to help improve balance and posture in those with injuries.

LifeMOD™ (Biomechanics Research Group, Inc.) is a biomechanics modeling environment based on the ADAMS mechanical systems software, that allows researchers to realistically simulate human movement, both visually and mathematically, by considering the body as a mechanical system consisting of mechanical components (like the NeuroCom platform), body segments, joints, forces, and a control system. The development of an automated locomotion analysis system is capable of using data collected in balance-related experiments to generate inverse dynamic simulations which provide kinematic and kinetic data. The model variables can include collected data such as subjects’ anthropometric data, 3-D posture data, and force plate data. These variables are integrated in the simulation to calculate model outputs, such as joint reaction forces and moments, ground reaction forces, and segmental velocities. This approach, combining experiment data and models, holds great potential for understanding and describing locomotion strategies for patients with spinal cord injuries. The lab is working closely with the Biomechanics Research Group, Inc. and Vicon, Inc. to validate these new balance and locomotion models.