GaitTrak Operations Guide

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:

Gait Marker Set

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.

GaitTrak Files

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.

Trial Collection

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:

References

de Leva, P. (1996). Adjustments to Zatsiorsky-Seluyanov's segment inertia parameters. Journal of Biomechanics, 29(9): p. 1223-1230.

Kadaba, M. P., Ramakrishnan, H. K., & Wootten, M. E. (1990). Measurement of lower extremity kinematics during level walking. Journal of Orthopaedic Research, 8(3), 383-392.

Perry, J., & Davids, J. R. (1992). Gait analysis: normal and pathological function. Journal of Pediatric Orthopaedics, 12(6), 815.

Sutherland, D. (2002). The evolution of clinical gait analysis: Part II Kinematics. Gait & Posture, 16(2), 159-179.

Sutherland, D. H. (2005). The evolution of clinical gait analysis part III - Kinetics and energy assessment. Gait and Posture, 21(4), 447-461.

Winter, D. (2005). Biomechanics of Motor Control and Human Movement. 3rd ed. Hoboken, NJ: John Wiley and Sons, Inc.

Zenzi, J., Richards, J., & Higginson, J. S. (2008). Two simple methods for determining gait events during treadmill and overground walking using kinematic data. Gait & Posture, 27(4), 710-714.