Evaluating dynamic error of a treadmill and the effect on measured kinetic gait parameters: Implications and possible solutions.


Type
Article
Change log
Authors
Garofolini, Alessandro 
Taylor, Simon 
Abstract

The dynamic properties of instrumented treadmills influence the force measurement of the embedded force platform. We investigated these properties using a frequency response function, which evaluates the ratio between the measured and applied forces in the frequency domain. For comparison, the procedure was also performed on the gold-standard ground-embedded force platform. A predictive model of the systematic error of both types of force platform was then developed and tested against different input signals that represent three types of running patterns. Results show that the treadmill structure distorts the measured force signal. We then modified this structure with a simple stiffening frame in an attempt to reduce measurement error. Consequently, the overall absolute error was reduced (-22%), and the error in force-derived metrics was also sufficiently reduced: -68% for average loading rate error and -80% for impact peak error. Our procedure shows how to measure, predict, and reduce systematic dynamic error associated with treadmill-installed force platforms. We suggest this procedure should be implemented to appraise data quality, and frequency response function values should be included in research reports.

Description
Keywords
Biomechanics, Calibration, Gait analysis, Ground reaction force, Running, Biomechanical Phenomena, Exercise Test, Gait Analysis, Humans, Kinetics, Mechanical Phenomena, Running
Journal Title
J Biomech
Conference Name
Journal ISSN
0021-9290
1873-2380
Volume Title
82
Publisher
Elsevier BV