The Motion Analysis Corp. walking gait analysis application will compute and report the primary biomechanical parameters during bipedal walking or running. It supplies a complete kinematic report of the lower extremity, and if force platforms are used, can supply kinetics measures and body center of mass location and velocities. Graphs are generated that compare multiple trials to standardized norms. The information can be used to indicate an inclination toward injury or to compare the technique and power output from each leg. This guide will step through the procedures to collect the trials, compute parameters, and generate reports.
What you need
A MAC Motion Capture system 29 Retroreflective Markers and configured as shown below:
Marker #14, the right Thigh, should be 1/3 the distance between the R. ASIS and R. Knee. Marker #16, the right Shank, should be 1/3 the distance between the R. Knee and R. Ankle. Marker #20, the Left Thigh, should be 2/3 the distance between the L. ASIS and L. Knee. Marker #22, the Left Shank, should be 2/3 the distance between the L. Knee and L. Ankle.
There are a number of files specific to this application that will be used by Cortex to help you set up, acquire and process your trials:
- GaitTrak.mars – holds the marker and segment information
- GaitTrak.cal – holds the event information
Data Collection Setup
Data collection for GaitTrak is similar to most standard collections. There are some settings for calibration and data collection that you should use that will help ease the process. Learn about the recommended data collection settings in Data Collection Setup.
You should already be familiar with how to collect 3D data using Cortex. However, GaitTrak requires some specific collection procedures to ensure correct calculations. Trial Collection describes the recommended workflow to collect your trials.
Running the GaitTrak Application
The GaitTrak software is simple to operate, and there are only a few fields to enter and several buttons to click. A video tutorial and some instructions for using the GaitTrak software are here:
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