Objective—To evaluate the use of a force plate as a
method for objective gait analysis in adult poultry, to
characterize ground reaction forces (GRFs) produced
in adult chickens during normal walking, and to assess
the variability of GRFs.
Animals—18 clinically normal 5-month-old Brown
Procedure—Vertical, craniocaudal, and mediolateral
GRFs were measured as hens walked across a standard
force plate embedded in the middle of a runway.
Results—All GRFs were significantly affected by
speed, and variability was high. With increasing
speed, overall stance time decreased, but the percentage
of stance time spent in braking or propulsion
remained approximately equal. There was an overall
increase in maximum propulsion force, which was
produced at a greater rate over a shorter time; thus,
propulsion integral decreased. Maximum braking
forces and braking integrals were variable, but the
rate at which the forces were generated increased.
Mediolateral forces were 2 to 3 times greater in hens
than values that have been reported for other species.
Conclusion and Clinical Relevance—A standard
force plate can be used to objectively measure GRFs
in walking adult hens; however, the large variation in
the data suggests that the technique in its current
form would be of limited clinical use. Overall, vertical
and craniocaudal forces had similar characteristics to
those of other species, whereas mediolateral forces
were found to be much greater in chickens than for
other species. (Am J Vet Res 2003;64:76–82)