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Step 7a – Collect data

Note: if the options to create a new player/session are not shown, select View > Project View.

Proceed to step 7b if you want to import existing files.

• Begin the capture by having the subject stand in the middle of the field of view. For sports marker set we recommend an A-pose, for other marker sets in the "ski pole" position.
• To record a static trial, click on the red box for the static file and select Capture to begin the capturing.

  

  Note: if you want to change the duration of the recording, select Edit settings and capture instead. QTM will remember the time you enter and will use it for all future trials you are recording for the measurement type within this project.

• Review the capture to ensure all markers are present. If required, crop the file to a section in which the subject was static and all markers were visible.

  

   

• If you need to capture another static file, uncheck the first one and another red box will appear.

• Next step is capture data to calculate functional hip or functional knee based on selected marker set. Repeat this procedure for 8 to 10 seconds. Subject is doing a "hula hop movement" for functional hip or mild squats for functional knee.
• Record dynamic trials (pitches, swings) following the same procedure. If QTM is set up to use "pre-trigger", you can press the trigger button after the player started moving.
• Should the AIM fail to identify all markers, label manually and add the file to the AIM model. See the QTM manual for details. It is recommended that you have one ‘master’ AIM model for all subjects and keep adding trials from different subjects to that model if the model does not identify all markers correctly. The following AIMs are used:

  For Baseball marker set:

  • Static and functional hip:
    • Baseball.qam
    • Mound.qam
  • Pitches:
    • Baseball.qam
    • Mound.qam
  • Swings:
    • Baseball_Hitting.qam

   

  For Sports marker set:

  • Static and functional knee:
    • Baseball_Sports.qam
    • Mound.qam
  • Pitches:
    • Baseball_Sports.qam
    • Mound.qam
  • Swings:
    • Baseball_Hitting_Sports.qam

   

  For Hybrid set:

  • Swings:
    • BaseballBat.qam

  Sports marker set can optionally use markers on pelvis and arms. If iliac crest (WaistL, WaistR) markers exist in dynamic trial, spina iliaca anterior superior (WaistLFront, WaistRFront) markers are used as calibration markers only. If RArm, LArm, LForeArm and RForeArm markers exist, they are added as additional tracking markers for upper arm and forearm respectively.

  Alternatively, the following AIM models and marker guides are provided in the folder [project folder]\AIM models\Legacy marker sets\ and supported for backwards compatibility with previous versions:

  • Baseball Standard legacy marker set
  • Baseball Performance legacy marker set

  If you would like to use one of the legacy AIM models or any other AIM model, copy it to [project root]\AIM Models\ ad rename it to replace one of the default AIM models listed above. The names of the AIM models must match exactly because QTM will select them automatically when you capture a file. Overwrite these models with new versions if required.

• Check that all markers are present and labelled correctly.

• For each pitch, a ‘Release’ event can be added manually at the time of ball release. For each swing, a ' Contact' event can be added manually at a time of ball contact with bat:

  • Find the time of ball release or contact by moving the slider at the bottom of QTM.
  • Select Edit > Events > Create New Event (or press Ctrl+E).

  • Type ‘Release’ or 'Contact' to name the event and click OK.

    

    Note: if 'Release'/'Contact' event is not set, Visual3D will atempt to detect them automaticaly.

• Optional: for pitching, if you find that the Visual3D does not identify the “Setup” (start of movement) and/or “Footstrike” automatically, create each or both events manually in QTM. Similarly, for hitting, if "Lead_Foot_Down" and "Lead_Foot_Off" are not identified correctly by Visual3D, create events manually in QTM. This works individually for each trial and overrides the automatic event detection. If force data exists, Footstrike event will be preferably detected from the force data.

  Make sure the QTM event name matches the spelling “Setup”, “Footstrike”, "Lead_Foot_Down" and "Lead_Foot_Off" exactly.

• For pitching, label the ball marker at least in the release frame and in the first five frames following the release event (ball speed will be calculated based on this marker). Optionally, if ball marker does not exist, it is possible to set ball speed manually in PAF pane. If ball marker does not exist and ball speed is not set manually, the ball speed is left empty in the report.

• Optionally, for pitching you can enter ball speed, spin rate, spin axis and pitch subtype for any measurement.

  

• Crop files to start approximately 1 sec before movement start to 1 sec after release. This will speed up the processing in Visual3D.

• Proceed with Step 8.

Step 7b – Import existing .qtm files

• If you want to process existing QTM files (that you recorded outside PAF), click on the red box for the corresponding file and select Import file.

  

  The files will be copied into the session folder and renamed to a standard name. Use the comments field if you want to make a note of the original file name.

• Repeat for all required files. Check that all files are labelled correctly and crop them if needed. If you need to label the files with AIM, see Step 7a and the QTM User Manual for details.

Step 7c – Import existing .c3d files

It is possible to use the PAF module with files that were recorded with motion capture systems from other vendors.

Prerequisites:

• Files must be exported to c3d format using the software that comes with your motion capture system.
• The marker set and marker names must match one of the following:
  • Qualisys Baseball Marker Set (see [QTM Project Folder]\Documentation\Baseball_Marker_Set.pdf)
  • Qualisys Sports Marker Set (see [QTM Project Folder]\Documentation\Baseball_Sports_Marker_Set.pdf)
  • MAC marker set (see [QTM Project Folder]\Documentation\Baseball_MAC_Marker_Set.pdf)
  • Driveline marker set (see [QTM Project Folder]\Documentation\Baseball_Driveline_Marker_Set.pdf)

Workflow:

• Open each c3d file with QTM software (File>Open) and save as .qtm file (File>Save As) in a temporary location.
• Import .qtm file into PAF structure as described in “Step 7b – Import existing .qtm files”. It does not matter whether files are imported into a "Baseball" or "Baseball Sports " session, the correct definitions will be used based on name of left ankle marker.

Note: Most types of c3d files can be imported into QTM but due to variations in how c3d files are written by different vendors, you may experience issues like missing/wrong force data. Please send affected c3d files to support@qualisys.com with information about the system you use to generate the c3d flies.