The topics covered in this section include:
The Induced Acceleration Analysis is run using the command analyze -S <setup file name>, for example,
Setup Files and XML Tag Definitions
Induced Acceleration Analysis Properties
The Induced Acceleration Analysis is performed using the AnalyzeTool (inputs defined in the section on Getting Started with Analyses) and is added to its set of Analyses. The specific XML properties for an Induced Accelerations analyis are presented below. You can also download the setup file used to analyze a running simulation as published in Hamner, SR, Seth, A, Delp, SL. Muscle contributions to propulsion and support during running, Journal of Biomechanics, vol. 43, pp. 2709-2716, 2010.
Example: Sample properties for the setup of an Induced Acceleration Analysis
Evaluating Induced Accelerations with Static Optimization Results
The Induced Acceleration Analysis uses the states and controls from a forward simulation or provided by the AnalyzeTool to compute all actuator forces, including muscle forces, and to apply them to the model to determine their contributions to the system acceleration. The Induced Acceleration Analysis does not directly take actuator forces as an input, however, if the option to <compute_potentials_only> is true, then all forces are set to unity (controls and states do not determine the applied force) and the result is the potential of that actuator to accelerate the system per unit of force (moment). The potentials can be used to compute the induced acceleration when muscle forces are known, for example, from performing Static Optimization. Taking the product of the muscle force (estimated from Static Optimization) and the potential of a muscle to accelerate a joint or the center of mass (from an Induced Acceleration Analysis) yields each muscle force's contribution to the acceleration of interest. The product of muscle forces and their potentials is easily performed using Excel or MATLAB.