Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

  1. You can use IK or RRA results as input kinematics. If using IK results, you usually need to filter them, either externally or using the OpenSim analyze/static optimization field; if using RRA results, you usually do not have to filter.
  2. For gait and many other motions, you need to add (append) residual actuators to the first free joint in the model (typically the ground-pelvis joint).
    1. There should be one actuator for each degree-of-freedom (i.e., FX, FY, FZ, MX, MY, MZ).
    2. These residual actuators are required because there is dynamic inconsistency between the estimated model accelerations and the measured ground reaction forces. This inconsistency can result from marker measurement error, differences between the geometry of the model and the subject, and inertial parameters.
    3. Running RRA will reduce—but not eliminate—these residuals. Thus, appending actuators is still necessary.
  3. See How Static Optimization Works and How to Use the Static Optimization Tool for more information.

Troubleshooting:

...