...
| Tip |
|---|
| Tip When you are familiar with these operations, you can run all of the data processing in a single step by creating a custom pipeline and adding all the operations described in this section to it, as explained in Create a pipeline. When you create your new pipeline, be sure to include the operations in the above order. |
...
This pipeline operation filters the data using the Woltring filter to ensure smooth trajectories for calculating kinetics. This routine is based on a fifth-order spline-interpolating function (for details on this function and its filtering algorithms, see Plug-in Gait references).
In the Properties pane for this operation, you can specify these settings:
...
| Property | Description |
|---|---|
| First Frame | First frame in which events are detected |
| Last Frame | Last frame in which events are detected |
| Only after existing | If a force plate is used and you select this option, Vicon Nexus automatically correlates force plate data events from the time of the first strike on the force plate and forward. If you do not select this option, Vicon Nexus automatically correlates events both forward and backward from the first force plate strike. If a force plate is not used, you can still select this option, but you must make a thorough visual check of the events placed. |
| Correlation Method (Advanced property) | Enables you to choose the correlation method to automatically place events at the correct location in the time bar: Legacy, Least Squares or Pearson Coefficient (see Correlation Method parameters in the Vicon Nexus Reference Guide). |
| Marker (Left and Right) | Enables you to change the marker used for correlation if necessary. |
| Component (Left and Right) | For walking trials, leave the Left and Right values at the default value (Z). For running and other motor tasks, change as appropriate. |
| Derivative (Left and Right) | For walking trials, leave the Left and Right values at the default value (Position). For running and other motor tasks, change as appropriate. |
...
In some instances, a foot may be in contact with more than one force plate simultaneously; for example, the heel may land on the far side of one plate and then the toes roll onto the near edge of the subsequent plate.
| Scroll pagebreak |
|---|
Dynamic Plug-in Gait includes an Advanced option to permit calculations based on these cross-plate strikes.
Reactions from the two plates are combined during processing, with the plate that is struck first being considered the primary. The forces reported by each plate are added together; the moments are also combined by referring the moment from the secondary plate back to the origin of the primary plate. In effect, the two plates are treated as a single force plate with the same origin as the primary plate.
...
You may also set the foot strike manually (see Add events to trials and also Automatically assess foot strikes).
Note that the existing restriction that there must be only a single foot in contact with any given force plate still applies.
...
This pipeline operation exports the current state of the processed data to a .c3d file. You can then import the data into other software for further processing or report generation. For example, in Vicon Polygon you can visualize the trajectories, kinematic model elements, and kinetics data. If you manually import the corresponding .vst file into Polygon, it also visualizes the bones. For more information, see Configure the Export C3D operation.