Clinical gait analysis: marker tracking accuracy of low-cost 3D optical motion analysis system
3D motion analysis is a method of collecting objective, accurate and repeatable data. However the high cost of equipment inhibits its widespread use in routine clinical practice. This study was designed to compare the tracking accuracy of a relatively low-cost Optitrack system compared with a gold-standard Vicon 612, and Vicon MX system.
A cluster of four reflective markers was attached to the thigh of a 32-year-old healthy male participant. 12 trials were captured with each system over a 7-day period. Accuracy and reliability of marker tracking was compared between low-cost Optitrack 3D motion analysis system and two more expensive systems (Vicon 612 and Vicon MX) during flat ground walking.
In terms of accuracy, vector magnitudes were within 2.1% between systems. The most reliable system was the Vicon MX, but the other systems had acceptably low variances in measurement. Optitrack therefore provides a low-cost reliable 3D motion analysis system, but does not support force platform or EMG data. > From: Carse et al., Physiotherapy (2013) (Epub ahead of print). All rights reserved to the Chartered Society of Physiotherapy. Published by Elsevier, Ltd.
The Pubmed summary of the article can be found here.
In the Youtube clips below you can view two examples of Optitrack camera system recordings.