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.

Kinematics of saddle and rider in high-level dressage horses performing collected walk on a treadmill.

REASONS FOR PERFORMING THE STUDY: The kinematics of the saddle and rider have not been thoroughly described at the walk. OBJECTIVE: To describe saddle and rider movements during collected walk in a group of high-level dressage horses and riders. METHODS: Seven high-level dressage horses and riders were subjected to kinematic measurements while performing collected walk on a treadmill. Movements of the saddle and rider's pelvis, upper body and head were analysed in a rigid body model. Projection angles were determined for the rider's arms and legs, and the neck and trunk of the horse. Distances between selected markers were used to describe rider position in relation to the horse and saddle. RESULTS: During the first half of each hindlimb stance the saddle rotated cranially around the transverse axis, i.e. the front part was lowered in relation to the hind part and the rider's pelvis rotated caudally, i.e. in the opposite direction. The rider's seat moved forwards while the rider's neck and feet moved backwards. During the second half of hindlimb stance these movements were reversed. CONCLUSION: The saddles and riders of high-level dressage horses follow a common movement pattern at collected walk. The movements of the saddle and rider are clearly related to the movements of the horse, both within and outside the sagittal plane. POTENTIAL RELEVANCE: The literature suggests that the rider's influence on the movement pattern of the horse is the strongest at walk. For assessment of the horse-rider interaction in dressage horses presented for unsatisfactory performance, evaluations at walk may therefore be the most rewarding. Basic knowledge about rider and saddle movements in well-performing horses is likely to be supportive to this task.

Quantitative analysis of stress echocardiograms in healthy horses with 2-dimensional (2D) echocardiography, anatomical M-mode, tissue Doppler imaging, and 2D speckle tracking.

BACKGROUND: Stress echocardiography is used to diagnose myocardial dysfunction in horses, but current methods are not well standardized. The influence of heart rate (HR) on measurements is largely unknown. OBJECTIVES: To investigate the use of 2-dimensional echocardiography (2DE), anatomical M-mode (AMM), tissue Doppler imaging (TDI), and 2D speckle tracking (2DST) at rest and after exercise for quantification of regional and global left-ventricular (LV) function. ANIMALS: Five athletic Warmblood horses; 11.6+/-3.6 years; 529+/-48 kg. METHODS: Prospective study. Three separate echocardiographic examinations were performed before (baseline) and over 5 minutes after treadmill exercise with 2DE (1st, short-axis view; 2nd, long-axis view) and pulsed-wave TDI (3rd examination). Offline analyses were performed at baseline and after exercise at HR 120, 110, 100, 90, and 80 minute(-1). Global and segmental measurements were compared by analysis of variance. RESULTS: Quantitative analyses of stress echocardiograms were feasible in all horses. None of the AMM indices changed significantly after exercise. Stroke volume and ejection fraction by 2DE and strain by 2DST decreased, whereas strain rate by 2DST increased significantly at HR>100 minute(-1). TDI analyses were technically difficult and provided little additional information. CONCLUSIONS AND CLINICAL IMPORTANCE: Volumetric indices by 2DE and strain and strain rate by 2DST are applicable for quantitative assessment of stress echocardiograms. In healthy horses, they are significantly altered at a HR>100 minute(-1) and need to be evaluated in view of the instantaneous HR. Further investigations are needed to define the clinical value of stress echocardiography in horses with cardiac disease.

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.

Basic kinematics of the saddle and rider in high-level dressage horses trotting on a treadmill.

REASONS FOR PERFORMING STUDY: A comprehensive kinematic description of rider and saddle movements is not yet present in the scientific literature. OBJECTIVE: To describe saddle and rider movements in a group of high-level dressage horses and riders. METHOD: Seven high-level dressage horses and riders were subjected to kinematic measurements while performing collected trot on a treadmill. For analysis a rigid body model for the saddle and core rider segments, projection angles of the rider's extremities and the neck and trunk of the horse, and distances between markers selected to indicate rider position were used. RESULTS: For a majority of the variables measured it was possible to describe a common pattern for the group. Rotations around the transverse axis (pitch) were generally biphasic for each diagonal. During the first half of stance the saddle rotated anti-clockwise and the rider's pelvis clockwise viewed from the right and the rider's lumbar back extended. During the later part of stance and the suspension phase reverse pitch rotations were observed. Rotations of the saddle and core rider segments around the longitudinal (roll) and vertical axes (yaw) changed direction only around time of contact of each diagonal. CONCLUSION: The saddles and riders of high-level dressage horses follow a common movement pattern at collected trot. The movements of the saddle and rider are clearly related to the movements of the horse and saddle movements also seem to be influenced by the rider. POTENTIAL RELEVANCE: Knowledge about rider and saddle movements can further our understanding of, and hence possibilities to prevent, orthopaedic injuries related to the exposure of the horse to a rider and saddle.

The effect of different head and neck positions on the caudal back and hindlimb kinematics in the elite dressage horse at trot.

REASONS FOR PERFORMING STUDY: Dressage involves training of the horse with the head and neck placed in a position defined by the rider. The best position for dressage training is currently under debate among riders and trainers, but there are few scientific data available to confirm or disprove the different views. OBJECTIVE: To evaluate the kinematic effects of different head and neck positions (HNPs) in elite dressage horses ridden at trot. METHODS: Seven high-level dressage horses were subjected to kinetic and kinematic measurements when ridden on a treadmill with the head and neck in 5 different positions. RESULTS: Compared to free trot on loose reins the HNP desired for collected trot at dressage competitions increased T6 vertical excursion, increased sacral flexion and decreased limb retraction after lift-off. Further increasing head or head and neck flexion caused few additional changes while an extremely elevated neck position increased hindlimb flexion and lumbar back extension during stance, increased hindlimb flexion during swing and further increased trunk vertical excursion. CONCLUSIONS: The movements of the horse are significantly different when ridden on loose reins compared to the position used in collected trot. The exact degree of neck flexion is, however, not consistently correlated to the movements of the horse's limbs and trunk at collected trot. An extremely elevated neck position can produce some effects commonly associated with increased degree of collection, but the increased back extension observed with this position may place the horse at risk of injury if ridden in this position for a prolonged period. POTENTIAL RELEVANCE: Head and neck positions influence significantly the kinematics of the ridden horse. It is important for riders and trainers to be aware of these effects in dressage training.

Relationship between the forces acting on the horse's back and the movements of rider and horse while walking on a treadmill.

REASONS FOR PERFORMING STUDY: The exact relationship between the saddle pressure pattern during one stride cycle and the movements of horse and rider at the walk are poorly understood and have never been investigated in detail. HYPOTHESIS: The movements of rider and horse account for the force distribution pattern under the saddle. METHOD: Vertical ground reaction forces (GRF), kinematics of horse and rider as well as saddle forces (FS) were measured synchronously in 7 high level dressage horses while being ridden on an instrumented treadmill at walk. Discrete values of the total saddle forces (FStot) were determined for each stride and related to kinematics and GRF. The pressure sensitive mat was divided into halves and sixths to assess the force distribution over the horse's back in more detail. Differences were tested using a one sample t test (P < 0.05). RESULTS: FStot of all the horses showed 3 peaks (P1-P3) and 3 minima (M1-M3) in each half-cycle, which were systematically related to the footfall sequence of the walk. Looking at the halves of the mat, force curves were 50% phase-shifted. The analysis of the FS of the 6 sections showed a clear association to the rider's and horse's movements. CONCLUSION: The saddle force distribution during an entire stride cycle has a distinct pattern although the force fluctuations of the FStot are small. The forces in the front thirds were clearly related to the movement of the front limbs, those in the mid part to the lateral flexion of the horse's spine and the loading of the hind part was mainly influenced by the axial rotation and lateral bending of the back. POTENTIAL RELEVANCE: These data can be used as a reference for comparing different types of saddle fit.

Kinetics and kinematics of the passage.

REASONS FOR PERFORMING STUDY: The load acting on the limbs and the load distribution between fore- and hindlimbs while performing specific dressage exercises lack objective assessment. HYPOTHESIS: The greater a horse's level of collection, the more load is shifted to the rear and that during the passage the vertical load on the limbs increases in relation to the accentuated vertical movement of the centre of mass. METHODS: Back and limb kinematics, vertical ground reaction force and time parameters of each limb were measured in 6 Grand Prix dressage horses performing on an instrumented treadmill at the trot and the passage. Horses were ridden by their own professional rider. RESULTS: At the passage, horses moved at a slower speed (-43.2%), with a lower stride frequency (-23.6%) and, therefore, higher stride impulses (+31.0%). Relative stance duration of fore- and hindlimbs and suspension duration remained unchanged. While at the trot the diagonal limbs impacted almost simultaneously, the hindlimbs always impacted first at the passage; the time dissociation between landing and lift-off remained unchanged. Because of the prolonged stride duration, stride impulse and consequently limb impulses were higher at the passage in the fore- as well as in the hindlimbs (+24.8% and +39.9%, respectively). Within the diagonal limb pair, load was shifted from the forehand to the hindquarters (percentage stride impulse carried by the forehand -4.8%). Despite the higher impulses, peak vertical forces in the fore- and hindlimbs remained unchanged because of the prolonged absolute stance durations in fore- and hindlimbs (+28.1% and +32.2%, respectively). CONCLUSIONS: Based on the intralimb timing, the passage closely resembles the trot. Compared to other head-neck positions, the higher degree of collection resulted in a pronounced shift in impulse towards the hindquarters. Despite the higher limb impulses, peak forces acting on the limbs were similar to those observed at the trot. POTENTIAL CLINICAL RELEVANCE: An understanding of load distribution between fore- and hindlimbs in relation to different riding techniques is crucial to prevent wear-and-tear on the locomotor apparatus.

Influence of different head-neck positions on vertical ground reaction forces, linear and time parameters in the unridden horse walking and trotting on a treadmill.

REASONS FOR PERFORMING STUDY: It is believed that the head-neck position (HNP) has specific effects on the loading pattern of the equine locomotor system, but very few quantitative data are available. OBJECTIVE: To quantify the effects of 6 different HNPs on forelimb-hindlimb loading and underlying temporal changes. METHODS: Vertical ground reaction forces of each limb and interlimb coordination were measured in 7 high level dressage horses walking and trotting on an instrumented treadmill in 6 predetermined HNPs: HNP1--unrestrained; HNP2--elevated neck, bridge of the nose in front of the vertical; HNP3--elevated neck, bridge of the nose behind the vertical; HNP4--low and flexed neck; HNP5--head and neck in extreme high position; and HNP6--forward downward extension of head and neck. HNP1 served as a velocity-matched control. RESULTS: At the walk, the percentage of vertical stride impulse carried by the forehand (Iz(fore)) as well as stride length and overreach distance were decreased in HNP2, HNP3, HNP4 and HNP5 when compared to HNP1. At the trot, Iz(fore) was decreased in HNP2, HNP3, HNP4 and HNP5. Peak forces in the forelimbs increased in HNP5 and decreased in HNP6. Stance duration in the forelimbs was decreased in HNP2 and HNP5. Suspension duration was increased in HNP2, HNP3 and HNP5. Overreach distance was shorter in HNP4 and longer in HNP6. CONCLUSIONS: In comparison to HNP1 and HNP6, HNPs with elevation of the neck with either flexion or extension at the poll as well as a low and flexed head and neck lead to a weight shift from the forehand to the hindquarters. HNP5 had the biggest effect on limb timing and load distribution. At the trot, shortening of forelimb stance duration in HNP5 increased peak vertical forces although Iz(fore) decreased. POTENTIAL RELEVANCE: Presented results contribute to the understanding of the value of certain HNPs in horse training.

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.

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.

Gait pattern of heifers before and after claw trimming: a high-speed cinematographic study on a treadmill.

The manner in which the claws contacted the ground at the walk was evaluated in 18 healthy heifers. The animals were filmed before and after claw trimming while walking on a treadmill using high-speed cinematography (500 frames/s). For each limb, 4 consecutive steps were recorded from a side and a frontal plane. The objectives of the study were to evaluate 1) the order of claw contact with the treadmill surface, 2) the initial claw contact area, and 3) the effect of trimming on claw contact patterns. The heifers placed their front feet on the ground in a plane sagittal to the shoulders, whereas the hind feet were advanced more toward the median plane. Before trimming, the lateral claws contacted the ground before the medial in 83% of front and 100% of hind limbs. Trimming changed the percentage to 92% in the front and to 97% in the hind limbs. The percentage with which the heel of the lateral claws became the region of initial contact with the ground increased from 47 to 64% in the front feet and from 50 to 78% in the hind feet. In the medial claws of the forelimbs, claw trimming shifted the region of initial contact from the toe to the abaxial wall and heel. In the hind limbs, the main region of initial contact of the medial claws became the abaxial wall. Weight bearing by the medial claw became visibly apparent only during the midstance, propulsion, and push-off phases. "Heel first" contact of the lateral claws in the front and hind limbs may be the normal gait pattern in cattle. On hard surfaces, this pattern may lead to overload and predispose to disease, especially in the hind limbs.

[Interactive educational DVD on hoof protection, horseshoeing and diseases of the hoof]. / Interaktives Lehrmittel Huf: Schutz, Beschlag und Erkrankungen.

Good cooperation between farrier, veterinarian and horse owner is an important prerequisite for optimal support of the horse with regards to shoeing and hoof health. The introduction of a joint educational aid aims to improve the level of education of both veterinarians and farriers. The interactive, multimedia approach represents an innovative new dimension in instruction techniques, predominantly provided through images and videos. The contents of the new teaching aid will focus on detailed anatomy of the foot and distal limb, as well as currently accepted shoeing practices and techniques and pathologic conditions of the hoof and foot.

[The art of horseshoeing--between empiricism and science]. / Die Kunst des Hufbeschlags--zwischen Empirie und Wissenschaft.

To correctly shoe a horse requires the farriers to have a good working knowledge of postural anomalies and movement patterns, as well as of the different concepts of horseshoeing and to be able to apply the appropriate technique to every individual horse they shoe. The correct technique for specific problem cases is frequently a subject of debate amongst specialists and many theories would benefit from objective gait analyses. The case study presented examines the influence of different shoeing conditions on selected gait analysis parameters. The measurements were conducted on a Warmblood mare: (A) shod with long toes, (B) properly trimmed without shoes, (C) conventionally shod with rolled toes and finally (D) shod using the 4-point technique. Data on force-, time- and distance parameters were recorded using an instrumented treadmill. First contact and breakover of the hooves were documented using high-speed videography. A long toe resulted in a prolongation of the breakover time and, therefore, in a prolongation of the second half of the stance phase. Additionally, the prolonged stance duration associated with an unaltered force impulse, led to decreased force peaks. It was possible to objectively record differences between the trimmed, unshod foot, the shod long-toe and the shod rolled toe configurations. The differences between the rolled toe and the 4 point shoe however, were minimal. Gait analysis is a technique well suited for objective evaluation of different shoeing techniques under standardised conditions.

[Kinetics of heifers and cows walking on an instrumented treadmill]. / Kinetische Auswertung des Schrittes von Jungrindern und Kühen auf einem instrumentierten Laufband.

OBJECTIVE: Kinetic data of stride characteristics and ground reaction forces of cattle become increasingly important as automated lameness detection may be installed in dairy cow housing systems in the future. Therefore, sound heifers and cows were measured on an instrumented treadmill to collect such basic data. MATERIAL UND METHODS: Nine heifers and 10 cows were trained to walk on an instrumented treadmill. Vertical ground reaction forces as well as step and stride timing and length variables were measured for all limbs simultaneously. On average, 16 stride cycles in cows and 24 strides in heifers were analysed in each case. RESULTS: The cows walked on the treadmill at an average speed of 1.2 ± 0.05 m/s (mean ± standard deviation), with a stride rate of 43.0 ± 1.9/min and a stride length of 1.68 ± 0.1 m. The heifers had average values of 1.3 ± 0.04 m/s, 53.7 ± 2.2/min and 1.49 ± 0.05 m, respectively. The stance duration relative to stride duration (the duty factor) was for the cows significantly longer in the forelimbs (67%) than in the hind limbs (64%). Force-time-curves of all limbs showed two peaks, one after landing (FP1) and another during push off (FP2). Vertical ground reaction force was highest for FP1 in the hind limbs, but for FP2 in the forelimbs. At all limbs, force minimum between the peaks occurred shortly before midstance. The vertical impulse carried by both forelimbs amounted to 53.7% of the total stride impulse in cows and to 55.0% in heifers. The location of the centre of body mass varied during the stride cycle but was always located more towards the front limbs. CONCLUSIONS: Cows and heifers showed a symmetrical walk with minimal intra-individual variations. Relative stride impulse of the front limbs was higher than that of the hind limbs. Peak vertical force in the hind limbs was highest at landing and in the forelimbs at push off. The present study offers kinetic data of sound cows and heifers which might be helpful as guidelines for automated systems for lameness detection in cattle.

Differences in rider movement pattern between different degrees of collection at the trot in high-level dressage horses ridden on a treadmill.

Collection is a central term in equine dressage, defined as a shortening of the horse's stride length with retained energy and hind limb activity. How collection is induced by the rider has yet not been investigated objectively. The aim of this study was therefore to compare the movement pattern of high-level dressage riders between free trot (loose reins), passage and a range of three speeds in collected trot. Both at higher speed in collected trot and in passage, the rider's pelvis became more caudally rotated and the rider's lumbar back became more flexed. However, in passage there was also a decrease in phase-shift between horse and rider movements, suggesting that the rider used the seat more actively. In free trot, the rider's pelvis was more cranially rotated, the lumbar back was more extended, the rider's body inclined more forwards, and the phase-shift between horse and rider was increased, compared to collected trot. The observed changes were partly explainable from changes in the horse's movement pattern. However, most differences in rider body position seemed unrelated to the horse's movements, but were in accordance with instructions in equestrian texts, suggesting that those changes were voluntarily adopted by the riders.