Comparison of two methods for analyzing kinetic gait data in dogs.

Objective-To compare results of single-point kinetic gait analysis (peak and impulse) with those of complete gait waveform analysis. Animals-15 healthy adult mixed-breed dogs. Procedures-Dogs were trotted across 2 force platforms (velocity, 1.7 to 2.1 m/s; acceleration and deceleration, 0.5 m/s(2)). Five valid trials were recorded on each testing day. Testing days 1 and 2 were separated by 1 week, as were days 3 and 4. Testing days 1 and 2 were separated from days 3 and 4 by 1 year. A paired t test was performed to evaluate interday and interyear differences for vertical and craniocaudal propulsion peak forces and impulses. Vertical and craniocaudal propulsion force-time waveforms were similarly compared by use of generalized indicator function analysis (GIFA). Results-Vertical and craniocaudal propulsion peak forces and impulses did not differ significantly between days 1 and 2 or days 3 and 4. When data were compared between years, no significant differences were found for vertical impulse and craniocaudal propulsion peak force and impulse, but differences were detected for vertical peak force. The GIFA of the vertical and craniocaudal force-time waveforms identified significant interday and interyear differences. These results were identical for both hind limbs. Conclusions and Clinical Relevance-Findings indicated that when comparing kinetic data over time, additional insight may be gleaned from GIFA of the complete waveform, particularly when subtle waveform differences are present. (Am J Vet Res 2012;73:189-193)