Gait determination and activity measurement in horses using an accelerometer

The observation of locomotor activity and resting behaviour is used to determine time budgets, which may give some indication for the assessment of horses' welfare concerning management and housing, As an alternative to time-consuming direct observations, a common automatic measuring method is the use of pedometers. One disadvantage of pedometers is the loss of information due to pooling of data, which also disallows the distinction of different gaits. In this study, the suitability of an accelerometer (MSR145 data logger) for automatic gait determination was tested. The aims of the study were to define acceleration value ranges for stand, walk, trot and gallop and to compare acceleration data with a commonly used pedometer (ALT-Pedometer). For the validation, 20 horses of different breeds and height at withers were all exercised in stand, walk, trot and gallop for 5 min each with both measuring devices attached to the left foreleg. Acceleration of the vertical leg movement was measured at a sampling rate of 10 Hz. Acceleration data was calculated per second and averaged over the entire 5 min interval to obtain acceleration values. Steps measured by the pedometer were accumulated during minimum sampling intervals of 1 min. For gait determination, breed classes Horse (>148 cm), Pony (<= 148 cm) and Icelandic horse were analysed separately. Results revealed a significant influence of gait on mean acceleration values without overlap between the different gaits, when Icelandic horses were considered separately from other horses and ponies. Therefore, data allowed the determination of gaits by definition of distinct acceleration value ranges for stand, walk, trot and gallop. A positive correlation between acceleration values measured by MSR145 data logger and step activity measured by ALT-Pedometer was found for stand and walk; trot and gallop could not be distinguished by the pedometer. The validation revealed a clear suitability of the MSR145 accelerometer for gait determination in horses. The MSR145 was shown to be a high-precision measuring device that appeared to be an advantageous alternative to pedometers for measurements of locomotor activity in horses. (C) 2014 Elsevier B.V. All rights reserved.