2D Analysis with the APAS step by
Basic APAS Instructions For 2D Analysis
Make certain entire activity will be in the field
of view of the camera
Record calibration points
Must be at least 4 coplanar points
Points should "encompass" activity to be analyzed
Activity should take place in same plane as calibration points
CAPTURE VIDEO TO COMPUTER
Connect video camera to computer using DV cable to frame grabber
Turn camera to VTR mode
Double click the STUDIO DV icon to open the capture program
Select the CAPTURE tab and use the VCR buttons to position the
videotape. Make certain that you position the video before the
section that you would like to capture. (Use the file cabinet icon
to change the location of the stored files)
Click the PLAY button to start the video and then click the START
CAPTURE button. At this point you can enter a name for the video
Enter the name and select Start Capture.
Select the STOP CAPTURE to stop recording the video to the
Perform the steps listed above for both the Data and the
Select FILE, EXIT to close the program.
TRIM THE VIDEO
Double click the APAS SYSTEM icon and then double click the
Click the AVI icon and select the video DATA file that has been
captured. The video file will open and the individual images will be
displayed in the top panel. Double click the image to make it full
screen. Double click again to return to reduced size.
Use the VCR buttons to position the video to the starting image.
Click the TRIM START icon and the SYNCH icon when the first image is
Click the PLAY icon to advance the video to the last image.
Click TRIM END when the last image is selected.
Select FILE, SAVE TRIMMING. You will see the Source file and a
field for the Destination file. Enter the name and path for the
destination file. NOTE: If you leave the same name, the original
file will be overwritten.
Repeat the steps listed above for the calibration point video
Select FILE, EXIT
DIGITIZE VIDEO FILES
Double-click the DIGITIZE icon in the APAS System folder.
Select FILE, NEW PROJECT and enter the path and filename for the
Enter the Sequence Parameters
Title- This is a label for the activity and for future reference
Units Used to specify the units for the analysis. This will be
used for reporting results.
#Points Used to specify how many points will be digitized
#Control Used to specify how many calibration points
TYPE Leave at System
Height Subjects height (in the units specified)
Weight Subjects weight
Select the POINT IDs button to specify the point names. Select
OK when done.
Select Control XYZ to enter the calibration coordinates (in units
Select OK from the Sequence Parameters menu to proceed to the
View Information menu.
Enter the View Information
Title Used to specify information particular to this camera
FrameRate Leave at 60
CameraID used as optional label
Camera X,Y,Z Not used
View Type leave at Stationary
Select OK to proceed
Click the AVI icon to open the video data file.
Select OK at the Video File Information menu.
Start the Digitizing process. The current point is listed on the
lower portion of the screen. All images begin with a "Fixed
Point" This is any point in the field of view that DOES NOT
MOVE. Then digitize the points in the order specified. Proceed image
by image until complete.
DIGITIZE CONTROL POINTS
Select CONTROL, DIGITIZE and then CONTROL, OPEN VIDEO, AVI FILE
and select the video calibration file. The file will be displayed in
multi-panel format. Just select the best image and then click OK.
Now digitize the Fixed Point and the Control Points in the order
When complete, select CONTROL, FINISH.
TRANSFORM/SMOOTH THE DATA
Select the DLT icon from the toolbar to open the Transform
In the View tab, select the file to be transformed from the
available views. There will usually only be one view available.
Leave the options in the Transormation and Smooth tabs at the
Click OK to proceed and then click OK when Filtering has been
ANALYZE THE DATA
Click the ANALYZE icon from the toolbar.
Click the NEW GRAPH icon from the toolbar
Click the FILE button and specify the analyzed file for display.
Click the ADD button to specify the desired parameters.
JointSeg #1 R.Foot, R.ankle, R.Knee, R.Hip
Joint/Seg#2 Not used for displcement
Component X (horizontal) or Y (vertical)
Select OK and then OK to graph the data.