Automatic detection of break-over phase onset in horses using hoof-mounted inertial measurement unit sensors

Abstract

A prolonged break-over phase might be an indication of a variety of musculoskeletal disorders and can be measured with optical motion capture (OMC) systems, inertial measurement units (IMUs) and force plates. The aim of this study was to present two algorithms for automatic detection of the break-over phase onset from the acceleration and angular velocity signals measured by hoof-mounted IMUs in walk and trot on a hard surface. The performance of these algorithms was evaluated by internal validation with an OMC system and a force plate separately. Seven Warmblood horses were equipped with two wireless IMUs which were attached to the lateral wall of the right front (RF) and hind (RH) hooves. Horses were walked and trotted over a force plate for internal validation while simultaneously the 3D position of three reflective markers, attached to lateral heel, lateral toe and lateral coronet of each hoof, were measured by six infrared cameras of an OMC system. The performance of the algorithms was evaluated by linear mixed model analysis. The acceleration algorithm was the most accurate with an accuracy between -9 and 23 ms and a precision around 24 ms (against OMC system), and an accuracy between -37 and 20 ms and a precision around 29 ms (against force plate), depending on gait and hoof. This algorithm seems promising for quantification of the break-over phase onset although the applicability for clinical purposes, such as lameness detection and evaluation of trimming and shoeing techniques, should be investigated more in-depth.

Influence of trimming, hoof angle and shoeing on breakover duration in sound horses examined with hoof‐mounted inertial sensors

“…The technical progress in measuring devices enables a continuous improvement in the applicability and accuracy of measurements. Recently, a novel hoof‐mounted inertial measurement unit (IMU) sensor system has been evaluated, fulfilling a high technical standard with good reliability and feasibility 19 . The aim of the current study was to investigate the effect of trimming, a change in hoof angulation and different types of shoeing on breakover duration with this new technical approach.…”

“…Recently, a novel hoofmounted inertial measurement unit (IMU) sensor system has been evaluated, fulfilling a high technical standard with good reliability and feasibility. 19 The aim of the current study was to investigate the effect of trimming, a change in hoof angulation and different types of shoeing on breakover duration with this new technical approach. With the increased sensitivity it is aimed to either confirm or reject the tendency observed in previous studies.…”

Stance Phase Detection by Inertial Measurement Unit Placed on the Metacarpus of Horses Trotting on Hard and Soft Straight Lines and Circles

“…Foot-on and heel-off are spatiotemporal events essential to calculate locomotor parameters, and especially the stance duration [ 8 , 9 ]. Commonly, the stance phase of one leg is defined as the moment between the hoof being completely laid flat on the ground (foot-on) to the take-off of the heel (heel-off) [ 10 , 11 ]. These events can be examined visually, but the temporal resolution of the human eye limits its precise distinction [ 12 ].…”

“…Studies investigated the horse gait events detection accuracy of IMUs mounted on the lateral quarter of the horse hoof. Thanks to this IMU location, they determined all the stance phase events, from the first hoof impact to complete take-off [ 10 , 11 ]. This protocol using IMUs mounted on the horse hoof is considered a reference method to detect foot-on and heel-off events [ 10 , 11 ].…”

“…Thanks to this IMU location, they determined all the stance phase events, from the first hoof impact to complete take-off [ 10 , 11 ]. This protocol using IMUs mounted on the horse hoof is considered a reference method to detect foot-on and heel-off events [ 10 , 11 ]. However, in routine investigation, the fixation on the hoof is critical because IMUs have to be glued on or screwed to the hoof.…”