The SCoRE and SARA operations are solely joint calibrations and are not a full kinematic model. If you want to produce kinematic outputs (for example, Joint Angles), the Hip Joint locations and Knee flexion axes must be input into a secondary full kinematic model such as Plug-in Gait.

When Nexus is installed, a version of Plug-in Gait written in MATLAB is also installed. The following steps describes how to use this model to calculate Plug-in Gait variables that use SCoRE hip joint centers and SARA optimized knee axes as their foundation. You are assumed to have run through the Advanced Gait Workflow (see Run the Advanced Gait Workflow).

Using Plug-in Gait Matlab with SCoRE and SARA

Plug-in Gait Matlab has been created for research purposes and to allow the incorporation of SCoRE and SARA within the modeling process.

To use Plug-in Gait Matlab with SCoRE and SARA, you run a static script followed by the dynamic script:

Process static Plug-in Gait

1. Load your static trial (created during Step 1: Static).
2. Run the AGW Process pipeline to calculate the SCoRE hip joint centers and SARA knee flexion axes outputs for the static trial.
3. Click on the Matlab tab.
   
   
   
   
4. In the Matlab script file field, browse to C:\Program Files (x86)\Vicon\Nexus2.#\SDK\Matlab and select StaticPiG.m.
5. In the Script arguments field enter the following values as a comma-separated string:
   
   • FirstFrame (a number)
   • LastFrame (a number)
   • MarkerSize (marker size in mm)
   • bAntTiltPos (true or false)
   • bLFootFlat (true or false)
   • bRFootFlat (true or false)
   • bHeadLevel (true or false)
     
   Static example: 
   1, 337, 14, true, true, true, true

   
   
   
6. After you have entered all the required information, click Run Script.
   The log file displays the relevant feedback.
   
   
   
   An extra set of Model Outputs are created - <AngleName>_M:
   
   
   
   
7. Save the trial.

Process dynamic Plug-in Gait

1. Load your dynamic trial (created in Step 6: Process).
2. Click on the Matlab tab.
3. In the Matlab script file field, browse to C:\Program Files (x86)\Vicon\Nexus2.#\SDK\Matlab and select DynamicPiG.m.
4. In the Script arguments field, enter the following values as a comma-separated string:
   
   • FirstFrame (a number)
   • LastFrame (a number)
   • MarkerSize (marker size in mm)
   • bAntTiltPos (true or false)
   • PelvisROG (0.31)
   • ThoraxROG (0.31)
   • ReactionFrame (a number: 0=proximal segment, 1=distal segment, 2=global frame)
   • PowerOutput (a number: 1=single value power, 3=3-component power)
   • bAllowCrossPlateStrikes (true or false, optional, default false). When this variable is set to true, Plug-in Gait combines the dynamics of foot strikes that straddle two adjacent plates.
   
   Dynamic example:
   1, 337, 14, true, 0.31, 0.31, 1, 1

   
   
   
5. After you have entered all the required information, click Run Script.
   The Log file displays all the relevant feedback.
   
    
   An extra set of Model Outputs is created: <AnglesName>_M, <ForcesName>_M, <ModeledMarkers>_M, <MomentsName>_M, <Plug-InGaitBonesName>_M, <PowerName>_M
   
   
   
   
6. Save the trial.