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- Prepare the model by adding additional markers. When previously scaling the model using OpenSim, additional markers, specific to the laboratory marker setup, were added from another file. Since AddBiomechanics does not currently support this feature, follow the steps below to add these markers to a new, modified model file.
- Copy the original model file (Rajagopal2015.osim) to a new file (e.g., Rajagopal2015_CustomMarkerSet.osim) before making any changes.
- The model file is an XML file. Open both the new model file and the additional marker set file (Scale/markerset_walk_preScale.xml) in a text editor. More info about the model format and suggestions for text editors can be found in the OpenSim Models File Format documentation.
- Add the additional markers to the new model file. For both files, all of the Markers can be found under the section <MarkerSet>, under a subsection called <objects>. Copy all of the Markers from the additional marker set file to the new model file (appending them to the list of markers, not replacing them), and save the new model file.
- Open the new model in OpenSim and check if additional markers have been added to the model. If the model does not load, check if the new model file has the required XML opening and closing tag (e.g., <Marker> and a corresponding </Marker>).
- Prepare the marker and ground reaction force data files.
- Copy the original marker (ExpData/motion_capture_walk.trc) and ground reaction force (grf_walk.mot) data files to new files (e.g., motion_capture_walk_trimmed.trc and grf_walk_trimmed.mot) before making any changes.
- In the new files, trim the beginning and end of the trial so that the time range remaining only contains times that are valid for use with Inverse Dynamics (as you did previously for RRA). It could be helpful to use an advanced text editor (e.g., Notepad++), Excel, or MATLAB to perform this step.
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