Functional Joints Post Processing

After accumulating and defining functional joint landmarks, it is necessary to post-process them from the Model Builder's Post-Process feature (click on the Post-Processing icon on the toolbar ).

All defined functional joint landmarks will appear in the top-half of the tab. Select a functional joint by checking the associated checkbox to make it active for the tab.

Once you're ready, click on “Compute CHECKED Landmarks” or “Compute ALL Landmarks” to compute the locations of your functional joint landmarks.

It is possible to specify that a file already open in the workspace can be used for the functional movement, or to load a C3D file from disk. Note that more than one file can be added to the list, but each landmark may only be assigned to one movement trial.

Motion trials need to be selected by checking the checkbox to be made active within the tab.

Note that the selected landmark was created with an Event Sequence defining the range of frames of the motion trial to use. If this is not the case, the user can select a start frame and an end frame for each landmark. The buttons “Set START Event to Current Frame” and “Set START Event to Current Frame” allow the user to play the animation of the movement trial and press the buttons at the appropriate frames. After loading the movement trials, they will appear in the bottom list box.

The processing results from a functional will appear as above. First the name and parameters that were specified, then a series of intermediate steps in the algorithm in Visual3D that most people can safely ignore when there are no errors.

If Visual3D cannot compute a functional joint landmark, try these troubleshooting steps:

1. Verify that the segments/target names in your functional joint definition also exist in your dynamic motion trial.
2. Try redefining your functional joint to use more combinations.
3. Try using a different dynamic motion trial (note, you should use a specific functional movement trial for this purpose and not a general movement trial).

Check out our documentation for defining functional joints.

Follow along with the Create a Functional Joint at the Right Hip tutorial for a complete walkthrough of the process.