A simple technique for determination of footfall patterns of animals during treadmill locomotion

This paper describes a direct on-line electronic method for determination of the quadrupedal footfall patterns of animals during locomotion. This technique involves the application of a 30 kHz AC carrier signal to a conductive treadmill belt. The time of contact of each paw on the belt is determined by recording the increased conduction of these carrier signals from the treadmill surface through the footpads to monopolar electrodes implanted in each limb. Since the carrier signal frequency is very high, filters may be employed to electronically separate this signal from electromyographic signals simultaneously obtained through the same electrodes. In comparison with the cinematographic methods typically used for analysis of footfall patterns, this technique is less time consuming, is just as accurate and also yields signals which can be used for on-line triggering applications.