Summary
Objective: To evaluate the accuracy of force plate gait analysis at the walk and trot in dogs
with low-grade hindlimb lameness. Material and methods: Nineteen healthy dogs and 41 dogs with low-grade unilateral hindlimb lameness due
to stifle or hip joint problems were walked and trotted over a force plate. Peak vertical
forces (PVF) were recorded, and a symmetry index (SI) was calculated from the PVF
of the hindlimbs. ‘Cut-off’ values were determined from the SI of the normal dogs.
These cut-off values were used to discriminate lame dogs from normal ones. Sensitivity
and specificity were evaluated for measurements at walk and trot, and the Cohen’s
Kappa coefficient (k) was used to determine the agreement between clinical lameness
and force plate measurements, and between force plate results at walk and trot. Receiver
Operating Characteristics (ROC) curve were plotted for both gaits to evaluate accuracy.
Results: The sensitivity of the measurements at walk was 0.63, and specifity was 0.95. The
sensitivity of the measurements at trot was 0.90, and specificity was 1.0. Moderate
agreement was found between force plate measurements at walk and trot, and between
clinical gait assessment and force plate measurements at walk. Good agreement was
found between clinical gait assessment and measurements at trot. ROC analyses revealed
the trot (94.7% [91.7%; 97.7%]) to be the more accurate test than the walk (85.0%
[80.1%; 89.9%]). Conclusion: The trotting gait was more sensitive and accurate than the walking gait for the differentiation
of dogs with a low-grade hindlimb lameness from normal ones using force plate gait
analysis.
Keywords
Force plate - walk and trot - low-grade lameness