Summary
The aim of this study was to assess, whether or not, visual grading of changes in
subject acceleration during force plate collection within a fixed, measured velocity
range was adequate to control acceleration/deceleration. A second question was, whether
or not, visual grading of the trials was adequate to prevent significant changes in
ground reaction forces within a controlled velocity range. Eight healthy, non-chondrodysplastic
dogs, of varying breeds, were used in the study. Each dog was tested in four different
protocols. The order in which the dogs completed the different protocols was determined
randomly. During all of the protocols, the dogs trotted across the measured testing
area within a velocity range of 1.6 to 1.9 m/s. The protocols varied in the amount
of acceleration or deceleration allowed in the testing area and the methods of evaluating
the acceleration or deceleration. Significant differences in ground reaction force
measurements were found, with variations in the acceleration and deceleration. The
majority of changes were found in the craniocaudal axis during acceleration and deceleration.
Vertical axis measurements were only altered in the rear limbs. Significant differences
were not found in any measurement (except the stance phase duration in the rear limb)
between the mechanically controlled minimal acceleration/deceleration variation protocol
and the visually controlled acceleration/deceleration variation protocol. While visual
observation was unable to consistently differentiate acceleration, or deceleration,
changes through the testing area, it was able to eliminate enough variation in ground
reaction force measurements so that differences were not found between the mechanically
controlled minimal acceleration/ deceleration variation protocol nor the visually
controlled acceleration/deceleration variation protocol. These results suggest that
either method of collection may be acceptable for data collection depending upon the
type of study being performed.
The effects of acceleration variation were examined in dogs undergoing force plate
gait analysis. Significant differences in ground reaction force measurements were
found, with variations in the acceleration and deceleration. The majority of changes
were found in the craniocaudal axis, during acceleration and deceleration. Visual
observation was unable to consistently differentiate variations in acceleration through
the testing area.
Keywords Gait analysis - ground reaction forces - acceleration