Evaluation of a single body IMU at the girth to monitoring horizontal and vertical parameters in warmblood horses at trot – a pilot study

Abstract

Inertial measurement unit (IMU) sensor-based techniques are becoming more popular with horse-owners as promising tools for objective assessment of the locomotor apparatus. The objectives of this study were to describe, evaluate and validate the parameters stride duration and vertical displacement at trot using a single body IMU-sensor. Study design: Prospective validation study comparing an IMU sensor with an 3D optical motion capture. Methods: A total of twenty-four Warmblood horses equipped with a sternal placed IMU sensor and reflective markers for optical motion capture (OMC) were hand-led in trot on a hard lane. Using algorithms, stride duration and vertical displacement were calculated for each trial from the IMU and optical motion capture data. Bias of the measured parameters was calculated as the mean difference in respectively seconds and centimeters between the IMU and OMC data, precision as the s.d. of these differences and upper and lower limits of agreement (LoAs) were also calculated using the Bland-Altman method. Conclusions: the single body inertial measurement unit can be used to quantify temporal and kinematic parameters at trot. However, precision of the kinematic parameter vertical displacement may not be sufficient yet to detect lameness-related changes. Further ‘big data’ research is warranted to evaluate whether this IMU is suitable for consumer use in the field.