Experimental Set-up

1. Mount markers 1-8 on bony anatomical landmarks, making sure there are three markers per body segment.
   
2. Have the subject stand with the anterolateral aspect of the leg to be measured facing the OPTOTRAK system. Ask the subject to move about. Observe the real-time marker location display on the computer monitor and make sure no marker is missing.
3. The calibration frame is relative to the force platform in this experiment. Y is in the direction of travel, X is toward the camera, and Z points upward from the platform. Take a calibration measurement
4. Measure the (mediolateral) distance (d) from the origin of the calibration frame to the center of the knee joint.
5. Sketch the leg, thigh, locations of the 6 markers, and the X-Y-Z coordinate system of the calibration frame for the lab report.
6. Have the subject facing in the direction of travel and with the anterolateral aspect of the leg to be measured facing the OPTOTRAK cameras. Ask the subject to walk in front of the OPTOTRAK system. Record the data.
   Data of Normal subject walking
   Data of subject with stroke walking before stretching-->Corresponding Video
   Data of subject with stroke walking after stretching
7. The 3-D marker coordinate files are in Matlab format. The data is arranged by markers. After loading the data files, type whos to see all eight marker variables. The first column of the marker variables are X coordinates, the second are Y coordinates, and the third is Z coordinates.
8. Save the Matlab data files to your own directory for future analysis (by clicking it with the right mouse button and selecting "Save Target As..."). You can play the video clips corresponding to the Optotrak marker data with Microsoft Media Player or other video players.

Note: Data files should be saved as .mat extension and video files can be viewed using Windows Media Player.

Analysis & Questions
Return to Challenge Overview
Return to Main