Comparison of speed-dependent time, force and spatial parameters between Franches-Montagnes and European Warmblood horses walking and trotting on a treadmill.

Speed alterations affect many gait analysis parameters. How horses adapt to speed is relevant in many equestrian disciplines and may differ between breeds. This study described changes in gait parameters in 38 Warmblood (WB) and 24 Franches-Montagnes (FM) horses subjected to an incremental speed test at walk (1.35-2.05 m/s) and trot (3.25-5.5 m/s). Time, force and spatial parameters of each limb were measured with an instrumented treadmill and analysed with regression analysis using speed as the independent variable. With higher speeds, stride rate, length, over-tracking distance and vertical ground reaction forces increased while the impulses decreased. The parameters followed the same linear or polynomial regression curves independent of breed, while the slope (linear) or incurvation (polynomial) often differed significantly between breeds. Some differences between the breeds were associated with height and speed (e.g. stride length at walk), and would disappear when scaling the data. The main differences between the breeds seem to stem from the movement of the hind limbs, with the FM obtaining long over-tracking distances despite the shorter height at withers. Some parameters relevant to gait quality could be improved in the FM to resemble WB movement by strict selection using objective measurements systems.

Prediction of continuous and discrete kinetic parameters in horses from inertial measurement units data using recurrent artificial neural networks.

Vertical ground reaction force (GRFz) measurements are the best tool for assessing horses' weight-bearing lameness. However, collection of these data is often impractical for clinical use. This study evaluates GRFz predicted using data from body-mounted IMUs and long short-term memory recurrent neural networks (LSTM-RNN). Twenty-four clinically sound horses, equipped with IMUs on the upper-body (UB) and each limb, walked and trotted on a GRFz measuring treadmill (TiF). Both systems were time-synchronised. Data from randomly selected 16, 4, and 4 horses formed training, validation, and test datasets, respectively. LSTM-RNN with different input sets (All, Limbs, UB, Sacrum, or Withers) were trained to predict GRFz curves or peak-GRFz. Our models could predict GRFz shapes at both gaits with RMSE below 0.40 N.kg-1. The best peak-GRFz values were obtained when extracted from the predicted curves by the all dataset. For both GRFz curves and peak-GRFz values, predictions made with the All or UB datasets were systematically better than with the Limbs dataset, showing the importance of including upper-body kinematic information for kinetic parameters predictions. More data should be gathered to confirm the usability of LSTM-RNN for GRFz predictions, as they highly depend on factors like speed, gait, and the presence of weight-bearing lameness.

[Heart rate and faecal cortisol metabolites measurements in horses at the Sechseläuten in Zurich]. / Messung von Herzfrequenzen und Kotcortisolmetaboliten bei Pferden am Zürcher Sechseläuten.

INTRODUCTION: The Zurich's Sechseläuten is a traditional festival of the Zurich guilds, in which around 500 horses take part. After a parade through the old town of Zurich, the riders gather at a big square to canter around a burning woodpile topped with an exploding effigy (the «Böögg¼). The level of stress experienced by the horses partaking in this event is subjected to increasing scrutiny. The aim of this study was to evaluate the stress load of the horses participating in the Sechseläuten procession more objectively by measuring heart rate and faecal cortisol metabolites. Twenty-three horse-rider pairs were voluntarily recruited from the guilds for participation in the study. For comparison purposes, three sections of the procession were simulated in terms of gait and distance travelled in a normal riding environment during a test day and observed during the Sechseläuten itself 16 days later: Counter march Bahnhofstrasse, parade Limmatquai and parade around the burning «Böögg¼. All horses were equipped with a heart rate measuring system with GPS tracking (Polar Team Pro®, Polar Electro Oy, Finland). Faecal samples for measuring cortisol metabolites were taken rectally immediately before and 24 hours after the events. Thirteen of the 23 horses were sedated during the Sechseläuten (Acepromazine, 0,1-0,2 mg/kg p.o.). The differences between the observation periods and groups (sedated/unsedated) were tested by analysis of variance (P.

INTRODUCTION: Le Sechseläuten de Zurich est une fête traditionnelle des guildes zurichoises à laquelle participent environ 500 chevaux. Après un défilé dans la vieille ville de Zurich, les cavaliers se rassemblent sur une grande place pour galoper autour d'un tas de bois en feu surmonté d'une effigie qui explose (le «Böögg¼). Le niveau de stress des chevaux participant à cet événement fait l'objet d'une attention croissante. L'objectif de cette étude était d'évaluer plus objectivement le niveau de stress des chevaux participant au cortège du Sechseläuten en mesurant la fréquence cardiaque et les métabolites fécaux du cortisol. Vingt-trois couples cheval-cavalier ont été recrutés volontairement dans les guildes pour participer à l'étude. À des fins de comparaison, trois sections du cortège ont été simulées en termes d'allure et de distance parcourue dans un environnement équestre normal lors d'une journée de test et observées ensuite pendant le Sechseläuten lui-même 16 jours plus tard: Contre-marche sur la Bahnhofstrasse, cortège sur le Limmatquai et chevauchée autour du «Böögg¼ en feu. Tous les chevaux ont été équipés d'un système de mesure de la fréquence un cardiomètre avec suivi GPS (Polar Team Pro®, Polar Electro Oy, Finlande). Des échantillons fécaux destinés à mesurer les métabolites du cortisol ont été prélevés par voie rectale immédiatement avant et 24 heures après les événements. Treize des 23 chevaux ont été mis sous sédation pendant le Sechseläuten (Acépromazine, 0,1­0,2 mg/kg p.o.). Les différences entre les périodes d'observation et les groupes (sédaté/non-sédaté) ont été testées par analyse de variance (P.

Effect of shoeing conditions on hoof dimensions in Icelandic and Warmblood horses.

In Icelandic horses (ICE), high, long hooves with added weights are often used to improve gait quality in competitions. From a biomechanical point of view, excessively long hooves can be problematic as they increase forces acting on the distal limb. The study aimed to determine if hoof capsule size and angle of ICE at competitions are comparable to those of Warmblood horses (WB) requiring shoeing. Hoof dimensions and balance were quantified in 13 horses of each breed at the beginning of a shoeing period (BSP), allowing a baseline comparison between breeds, as well as for WB at the end of a shoeing period (ESP) and for ICE when shod for competition (COMP). Left front and hind hoof capsules and bony structures of the hooves were measured on lateromedial and dorsopalmar/dorsoplantar radiographs at BSP (ICE, WB), ESP (WB) and COMP (ICE), respectively, using the software Metron-Hoof-Pro. Compared to WBBSP, ICEBSP had larger hoof capsules relative to the size of P3 and, when controlled for withers height, longer dorsal hoof wall lengths. The comparison of ICECOMP to WBESP indicated that the relative increase in hoof length and volume was greater in ICECOMP compared to WBESP. Hoof balance was closer to previously published values in WBs, while hoof angles in ICE (particularly palmar/plantar angle of P3) were generally larger and thus less problematic. In conclusion, hooves of ICECOMP were relatively larger and less balanced than WBESP, but hoof angles in WB were smaller than in ICE.

Hoof conformation in Icelandic competition horses and its interrelationship with hoof pathologies and tölt performance.

In order to improve the four-beat-rhythm and forelimb action of the tölt in Icelandic horses (ICE), special shoeing techniques are applied particularly in the front hooves by increasing hoof length and height, or by adding weight to the distal limbs. Although regulations limit dorsal hoof wall length (LDHW) in competition ICE, their shoeing often deviates from a biomechanically optimal distal limb conformation. This study aimed to qualitatively and quantitatively describe current shoeing practices of ICE in competition. Moreover, the influence of LDHW on the occurrence of deviations from a standard hoof conformation, as well as on tölt performance was investigated. At four European competition sites, hoof dimensions of 133 randomly selected ICE were measured manually, and limb conformation and hoof balance were described. Dorsopalmar/-plantar and lateromedial radiographs of the left front and hind hooves were taken of each horse. Various parameters related to hoof dimensions and balance were measured on radiographs using the Metron-Hoof-Pro software. Flares of the dorsal hoof wall had the highest prevalence of all investigated hoof deformities. Multiple logistic regression analysis revealed that longer LDHW was associated with the occurrence of toe flares (P = 0.045), a broken hoof pastern axis (P = 0.003), and asymmetry of the quarter wall heights (P = 0.015). However, horses with a longer LDHW achieved higher scores in competition. In spite of its positive effect on tölt performance, a long LDHW is not recommendable as it may be associated with a higher prevalence of certain hoof deformities.

Lateral movement of the saddle relative to the equine spine in rising and sitting trot on a treadmill.

Saddle slip, defined as a progressive lateral displacement of the saddle during ridden exercise, has recently been given attention in the scientific press as a potential sign of lameness. The aim of this study was to objectively quantify the normal lateral movement (oscillations) of the saddle relative to the horse in non-lame horses, and associate this movement to the movements of the horse and rider. Data from seven Warmblood dressage horses competing at Grand Prix (n = 6) or FEI Intermediate (n = 1) level, ridden by their usual riders, were used. Simultaneous kinetic, kinematic and saddle pressure measurements were conducted during sitting and rising trot on a force-measuring treadmill. The maximum lateral movement of the caudal part of the saddle relative to the horse's spine (MAX) was determined for each diagonal step. A mixed model was applied, with MAX as outcome, and T6 and S3 vertical position, rigid body rotation angles (roll, pitch, yaw) of the horse's and rider's pelvis, vertical ground reaction forces, saddle force, and rider position (rising in rising trot, sitting in rising trot or sitting in sitting trot) as explanatory variables. The least square means for MAX were 14.3 (SE 4.7) mm and 23.9 (SE 4.7) mm for rising and sitting in rising trot, and 20.3 (SE 4.7) mm for sitting trot. A 10 mm increase in maximum pelvic height at push off increased MAX by 1.4 mm (p<0.0001). One degree increase in rider pelvis roll decreased MAX 1.1 mm, and one degree increase in rider pelvis yaw increased MAX 0.7 mm (both p<0.0001). The linear relationships found between MAX and movements of both horse and rider implies that both horse and rider movement asymmetries are reflected in the lateral movements or oscillations of the saddle in non-lame horses.

Vertical movement symmetry of the withers in horses with induced forelimb and hindlimb lameness at trot.

BACKGROUND: The main criteria for lameness assessment in horses are head movement for forelimb lameness and pelvic movement for hindlimb lameness. However, compensatory head nod in horses with primary hindlimb lameness is a well-known phenomenon. This compensatory head nod movement can be easily misinterpreted as a sign of primary ipsilateral forelimb lameness. Therefore, discriminating compensatory asymmetries from primary directly pain-related movement asymmetries is a prerequisite for successful lameness assessment. OBJECTIVES: To investigate the association between head, withers and pelvis movement asymmetry in horses with induced forelimb and hindlimb lameness. STUDY DESIGN: Experimental study. METHODS: In 10 clinically sound Warmblood riding horses, forelimb and hindlimb lameness were induced using a sole pressure model. The horses were then trotted on a treadmill. Three-dimensional optical motion capture was used to collect kinematic data from reflective markers attached to the poll, withers and tubera sacrale. The magnitude and side (left or right) of the following symmetry parameters, vertical difference in minimum position, maximum position and range-up were calculated for head, withers, and pelvis. Mixed models were used to analyse data from induced forelimb and hindlimb lameness. RESULTS: For each mm increase in pelvic asymmetry in response to hindlimb lameness induction, withers movement asymmetry increased by 0.35-0.55 mm, but towards the contralateral side. In induced forelimb lameness, for each mm increase in head movement asymmetry, withers movement asymmetry increased by 0.05-0.10 mm, in agreement with the head movement asymmetry direction, both indicating lameness in the induced forelimb. MAIN LIMITATIONS: Results must be confirmed in clinically lame horses trotting overground. CONCLUSIONS: The vertical asymmetry pattern of the withers discriminated a head nod associated with true forelimb lameness from the compensatory head movement asymmetry caused by primary hindlimb lameness. Measuring movement symmetry of the withers may, thus, aid in determining primary lameness location.

Quantification of the effect of instrumentation error in objective gait assessment in the horse on hindlimb symmetry parameters.

BACKGROUND: Objective gait analysis is becoming more popular as a tool assisting veterinarians during the clinical lameness exam. At present, there is only limited information on the effect of misplacement of markers/motion-sensors. OBJECTIVES: To investigate and describe the effect of marker misplacement on commonly calculated pelvic symmetry parameters. STUDY DESIGN: Experimental study. METHODS: Each horse was equipped with custom-made devices consisting of several reflective markers arranged in a predefined manner with a reference marker correctly positioned regarding the anatomical landmark and several misplaced markers along the sagittal and transverse planes. Linear regression analysis was used to estimate the effect of marker misplacement. RESULTS: For the tubera sacrale, each cm of left/right misplacement led to a difference in minimum position of the pelvis (PDmin) of ±1.67 mm (95% CI 1.54-1.8 mm) (P<0.001); maximum position of the pelvis (PDmax) was affected by ±0.2 mm (95% CI 0.071-0.33 mm) (P = 0.003). With respect to cranial/caudal misplacement, each cm of misplacement resulted in a PDmin difference of ±0.04 mm (95% CI -0.09 to 0.16 mm) (P = 0.56) and a PDmax difference of ±0.008 mm (95% CI -0.13 to 0.12 mm) (P = 0.9). For the tubera coxae, each cm of vertical misplacement led to a difference in the displacement amplitude between left and right tubera coxae (Hip-Hike_Diff) of ±1.56 mm (95% CI 1.35-1.77 mm) (P<0.001); for the cranial/caudal misplacement, this was ±0.82 mm (95% CI 0.66-0.97 mm) (P<0.001). MAIN LIMITATIONS: Only three horses were used in this experiment and the study design did not permit to determine the influence of marker misplacement on the evaluation of different degrees of lameness. CONCLUSIONS: Marker misplacement significantly affects calculated symmetry parameters of the pelvis. The observed errors are overall small but significant. In cases of mildly asymmetrical horses, this error might influence the decision-making process whereas in more severe asymmetries, the influence of the error effect may become less significant.