title: Testing of a tri-instrumented-treadmill unit for kinetic analysis of locomotion tasks in static and dynamic loading conditions.
abstract: In this study, we present a multi-treadmill system instrumented with three force platforms capable of measuring vertical and shear ground reaction forces and moments during both walking and running. Linearity, belts speed variations, repeatability of the measures, cross-talk, natural frequency, instrumental noise, moving part induced noise and drift were investigated. The noise due to vibrations and to moving parts was also investigated having a subject walking and running on the treadmill. The linearity test results showed a high linearity of all three treadmill force platforms, and vertical force natural frequency values of 219, 308, 307Hz, obtained for the three force platforms, were considered appropriate for the investigation of walking and running. The instrumental noise did not appear to be a significant source of error. The characteristics of the noise due to vibrations and moving parts changed when in the presence of a subject walking and running on the treadmill. For walking trials, averaging of gait cycles led to a systematic improvement of the signal to noise ratio, particularly for the medio-lateral component of the force. For running trials, even though averaging was not as beneficial as for walking trials, the greater force amplitude led to a better signal to noise ratio value. This instrumented treadmill demonstrated acceptable accuracy and signal to noise ratios for all ground reaction force components such that it can be useful for a variety of research and clinical gait analysis applications.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Virginia Health System, 545 Ray C. Hunt Drive, Suite 240, Box 801004, Charlottesville, VA 22908-1004, USA. gp6h@virginia.edu
authors.forename: Gabriele
authors.initials: G
authors.lastname: Paolini
authors.forename: Ugo
authors.initials: U
authors.lastname: Della Croce
authors.forename: Patrick O
authors.initials: PO
authors.lastname: Riley
authors.forename: Frederic K
authors.initials: FK
authors.lastname: Newton
authors.forename: D
authors.initials: D
authors.lastname: Casey Kerrigan
mesh_terms: D000054:Acceleration; D001696:Biomechanical Phenomena; D003625:Data Collection; D003654:Deceleration; D019544:Equipment Failure Analysis; D005080:Exercise Test / Q000295:instrumentation / Q000379:methods*; D005684:Gait / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007700:Kinetics; D008124:Locomotion / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D015203:Reproducibility of Results; D012420:Running / Q000502:physiology; D016138:Walking / Q000502:physiology