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Equine locomotion: 3. The reproducibility of gait in Standardbred Trotters
Equine Veterinary Journal
Abstract
The reproducibility of certain gait characteristics was investigated in Standardbred trotters at a speed of 12.0 m/sec. Twenty‐two horses were recorded twice on the same day and 4 of them on a third occasion 3 years later. The short‐term reproducibility was shown to be very good. In the long‐term study it was found that the stride length and duration of swing and stride had increased. This was interpreted as an effect of training.
Summary
La reproductibilité de certains caractères du trot fut étudiée chez les Standardbred à la vitesse de 12 m/sec. 22 chevaux furent filmés deux fois le même jour et 4 d'entre eux le furent une troisième fois 3 ans plus tard.
La reproductibilitéà court terme fut jugée très bonne. A long terme, on constata que la longueur de la battue, que les durées de la battue et du temps en suspension étaient accrues. On interpréta ceci comme étant le résultat de l'entraînement.
Zusammenfassung
Die Reproduzierbarkeit bestimmter Gang‐Merkmale wurde an Trabern bei einer Geschwindigkeit von 12 m/sec untersucht. 22 Pferde konnten am gleichen Tag zweimal studiert werden, vier davon ein drittes Mal drei Jahre später. Die kurzzeitige Reproduzierbarkeit der Werte erwies sich als sehr gut; langzeitig zeigte sich, dass Schrittlänge, Schritt‐ und Hangbeinphasendauer länger geworden waren, was als Aus‐wirkung des Trainings angesehen wurde.
... The influence of training on locomotor pattern has also been investigated. Drevemo et al. 4 reported the locomotor changes observed in four Standardbred trotters between four and seven years of age, resulting from the effect of training. Other studies have reported the effect of training by comparing the locomotion of young horses involved in a training programme with that of a control group 1,5 . ...
... These findings are in accordance with previous studies investigating the effect of training on locomotor variables. Drevemo et al. 4 compared the temporal variables of four Standardbred trotters on the track at the age of four and then three years later. At a velocity of 12 m s 21 , they found a significant increase in stride and swing duration, and no significant change in stride length and stance duration. ...
In Standardbreds, the main aim of early training (begun during the growth period) is the mechanization of athletes leading to a particular gait called the ‘flying trot’. The present cross-sectional study was undertaken to investigate the biomechanical and physiological factors involved in this gait change, and aimed to analyse the effect of age on gait and energetic variables in a population of Standardbred horses under training. One hundred and forty-three horses aged from two to seven years were tested on a track at three speeds (8.5, 10 and 11.6 m s−1) with a gait-analysis system. Gait variables (temporal and linear variables, symmetry, regularity, two-beat rhythm, dorso-ventral, longitudinal and lateral activities) were compared between four age groups (two-, three-, four-, and five-year-olds and above). After a standardized exercise test, two energetic variables (V4 and V200) were also compared between these groups. Most variables were influenced by age/training status. The results indicated that, from young to mature racehorses, stride length and duration increase; and gait becomes more symmetric and more regular. We also observed a decrease in dorso-ventral, longitudinal and lateral activities, i.e. a decrease of thoracic displacements. These differences could be elucidated at slow speed and were still obvious at high speed. V4 and V200 also increased significantly with age/training status. All of these results indicate an improvement in co-ordination and a decrease in metabolic cost with increasing age/training status. Thus gait acquisition could be related to an improvement in trotting efficiency.
... Consideration should also be given to the effect of the handler of the horse during in-hand trials. Handlers as well as drivers of the horses difnique.[17][18][19][20][21] In one study 21 asymmetries in the locomotion patterns of younger Standardbreds were proposed to be a further manifestation of congenital laterality or sidedness. ...
Background
Lameness evaluation of Standardbred trotters can be challenging due to discrepancies in observed movement asymmetry between in‐hand and track exercise, and between different trotting speeds. There are few studies on objective measurement of movement in Standardbreds, and little knowledge regarding biological variation and clinical significance of measured movement asymmetry in this breed.
Objectives
To quantify the prevalence and magnitude of objectively measured movement asymmetry in young Standardbred trotters, and identify associations with trainer, sex, height, track type and in‐hand measurement prior to or after track trials.
Study design
Cross‐sectional, observational study.
Methods
A total of 114 Standardbred yearlings were evaluated with a wireless inertial sensor system during trot in‐hand and when driven on a track. After exclusions relating to lameness or technical difficulties, 103 horses were included in the study; 77 were evaluated in‐hand and on the track, 24 only in‐hand and 2 only on the track.
Results
Front and/or hindlimb parameters were above asymmetry thresholds previously established for other breeds during in‐hand trials for 94 (93%) horses and during track trials for 74 (94%) horses. Most horses showed mild asymmetry. A minority of horses (20%) switched side of the asymmetry for one or more parameters between in‐hand and track trials. Mixed model analyses revealed no significant effects of trial mode (in‐hand or track trial, in‐hand trial pre‐ or post‐track trial, straight or oval track), trainer or horse height. Females had a significant but small reduction in asymmetry in one front limb parameter (HDmax) compared with males (1.7 mm, 95% CI 0.18‐3.28, P = .03).
Main limitations
High data variability, reflected in large trial standard deviations, relating mainly to a lack of horse compliance.
Conclusions
A high proportion of Standardbred yearlings showed movement asymmetries. There was no group‐level effect between in‐hand and track trials, however, considerable individual variation was observed.
... m/s [5]. In trot and pace, the movements of a fore and hind limb are synchronized by pairing diagonally or laterally, giving a two-beat rhythm [6][7][8][9]. The speed range for trotting dressage horses has been reported to be 3.2-4.9 ...
Gaits are typically classified as walking or running based on kinematics, the shape of the vertical ground reaction force (GRF) curve, and the use of inverted pendulum or spring-mass mechanics during the stance phase. The objectives of this review were to describe the biomechanical characteristics that differentiate walking and running gaits, then apply these criteria to classify and compare the enhanced natural gait of collected trot with the artificial gaits of passage and piaffe as performed by highly trained dressage horses. Limb contact and lift off times were used to determine contact sequence, limb phase, duty factor, and aerial phase duration. Ground reaction force data were plotted to assess fore and hind limb loading patterns. The center of mass (COM) trajectory was evaluated in relation to changes in potential and kinetic energy to assess the use of inverted pendulum and spring-mass mechanics. Collected trot and passage were classified as running gaits according to all three criteria whereas piaffe appears to be a hybrid gait combining walking kinematics with running GRFs and COM mechanics. The hind limbs act as springs and show greater limb compression in passage and piaffe compared with trot, whereas the forelimbs behave more like struts showing less compression in passage and piaffe than in trot.
... It has been assumed that gait change with training. Drevemo (1980) described an increase of stride length and duration of swing and stride with four standard bred trotters after three years of training. The trot of 12 two and a half year old dutch warmblood was evaluated on a treadmill after 70 days of training (Back 1995). ...
The purpose of this study was to analyse the gait changes in young horses trained for dressage. An accelerometric device fixed at the sternum measured the dorsoventral and longitudinal acceleration of the riding horse. Fourteen young horses (4, 5 and 6 year-olds) trained for dressage were recorded during dressage tests. They were tested during three years. Eight variables were calculated to quantify the rhythm, the regularity, the symmetry, the longitudinal and vertical activities of each figure of dressage test at trot. A variance analysis tested the effect of the first three years of dressage training on the trot variables. It was found that stride frequency decreased significantly (P<0.05) after two years of training (1.34 stride/s at the beginning of training and 1.26 strides/s at six year old) and that dorsoventral displacement increased after one year of dressage training before stabilizing at 0.1 3 m (P<0.05). However, the symmetry and the regularity of the trot could be altered at some point during training.
... Injury risk in general appears to be lower on softer going [73,[79][80][81][82]] than on firmer ground; however, this picture is complicated for different injury syndromes. The risk of distal limb fracture in both Thoroughbred [80,83,84] and Standardbred [85] racehorses increases on firmer ground [83] and the risk of tendon injuries generally increases on firm ground [86]. However, dressage horses that regularly train on a surface that becomes deep in wet weather, are more likely to sustain injuries than horses training on a firmer surface [70] and softer ground is associated with a greater risk of falling and therefore sustaining injury in both eventing [87] and the Grand National [88]. ...
The equine limb has evolved for efficient locomotion and high-speed performance, with adaptations of bone, tendon and muscle. However, the system lacks the ability seen in some species to dynamically adapt to different circumstances.The mechanical interaction of the limb and the ground is influenced by internal and external factors including fore-hind mass distribution, lead limb, moving on a curve, shoeing and surface properties. It is unclear which of the components of limb loading have the largest effect on injury and performance but peak load, impact and vibration all play a role. Factors related to the foot-ground interface that limit performance are poorly understood. Peak performance varies vastly between disciplines, but at high speeds - such as racing and polo - force and grip are key limits to performance.
... The pastured group in our study also decreased its stance percentage, but this was merely caused by an increase in swing(s) and stride duration. The latter phenomenon was also considered a training effect in 4 young Standardbreds that were trained over a 3 year period (Drevemo et al. 1980). Therefore, the definition and effects of 'training' appear to be rather relative. ...
To study the influence of training on the equine locomotor apparatus, the kinematics of 24 almost two-and-a-half-year-old Dutch Warmbloods were recorded on a treadmill at the trot (4 m/s) using a modified CODA-3 apparatus before and after a period of 70 days. In that period, 12 horses of the group were trained for dressage and jumping, while the other 12 were sent to pasture day and night. After 70 days, the hindlimb of the trained horses showed a decreased stance duration, less limb flexion and it reached its maximal protraction earlier in the stride. The stride duration remained the same in the trained horses, while the protraction and retraction range of the forelimb decreased in this group. In the pastured group, however, the horses increased their total range of forelimb movement in the sagittal plane and had a longer swing and stride duration. These results indicate that the definition of ‘training’ is rather relative. The response in the trained group was in agreement with the observation that the majority of horses from this group were trotting with impulsion ‘on the bit’. The pastured group was trotting in a more relaxed way with a longer stride duration and thus a lower stride frequency. In conclusion, this study proved that horses show different responses in their locomotor apparatus depending on the ‘training’ regime received. Using modern gait analysis equipment these differences could be evaluated objectively.
... If the motion is arrhythmic, additional non rhythmic movements occur. Factors that in¯uence the rhythmic and arrhythmic locomotion patterns of horses include: (i) conformation (Gunn 1983) and training (ii) innate and learned motion patterns (Persson 1967), anatomy and the horse's physical condition (Drevemo et al. 1980). The behaviour of rhythmic events in wild life populations (Bergerud 1975) and human locomotion (Hurmuzlu & Basdogan 1994) has been documented. ...
As in many other sports, e.g. gymnastics, judging dressage riding is problematic because the score is subjective. The aim of this study was to find a suitable method to support education of dressage judges and training of riders with a measurable criterion for riding harmony in the trot. We analysed the consistency of motion pattern 40 different rider–horse systems in trot (20 horses and 2 riders). A high-speed (120 Hz) 3D video system for motion analysis was used to track 20 markers taped to the horse and the rider. The angle between the line connecting the rider’s head to the rider’s back and that between the rider’s back to the horse’s head was calculated. Angular velocity and angular acceleration were derived. The lengths of the resulting vectors (LV) in the phase space were computed. Riding harmony was defined in terms of the average deviation of LV in the phase space.
The results of our study showed the professional rider–horse system had a significantly (P < 0.05) lower average deviation of LV (11.5% ± 1.4) than the recreational rider–horse system (13% ± 2.8). Thus, the professional rider–horse system had a motion pattern that was more consistent than the recreational rider–horse system and this was correlated to the average dressage scores, which were significantly (P < 0.001) higher for the professional rider (mean score ± SD, 7.3 ± 2.7) than those for the recreational rider (4.1 ± 3.0). As motion pattern consistency is one of the main characteristics of riding harmony, the results of these measurements can be used for education of dressage judges and riders.
... The proportion of between-individual variation observed here was lower than that reported in trotting horses (Drevemo et al., 1980a(Drevemo et al., , 1980b(Drevemo et al., and 1980c and humans (Kadaba et al., 1989). However, the present study showed that when environmental conditions were constant and cows were not lame, the cows could reproduce their preferred walking speed over time fairly well. ...
The variability in dairy cow gait characteristics, determined by measurements of footprints (trackway measurements), was analysed. Seven gait parameters were determined from 32 non-lame dairy cows during free-speed walking on a slatted concrete walkway. The footprints were revealed by application of a thin lime powder-slurry layer to the walkway surface. The cows were observed on two test occasions with a 3-week interval, with measurements from four consecutive strides used within each test session. The variance components for cow, test and cow-test interaction were estimated by a residual (restricted) maximum likelihood method. The percentage of each variance component was calculated to assess the relative impact of each factor on total variance. Between-test variation was generally low, suggesting that cows maintain the same average gait pattern, at least over a 3-week period. The proportion of within-test variation was considerable for most trackway measurements. Stride length, step angle, step width and tracking (overlap) showed low to moderate within-test variation (12% to 27%), whereas for mediolateral displacement of rear feet and step length it was rather high (54% and 62%, respectively). Within-test variation in step asymmetry was very high (77%), suggesting the occurrence of natural, non-systematic changes in inter-limb coordination in non-lame cows. For better understanding the gait pattern in non-lame cows, linear associations between the trackway measurements and with body size were assessed. It was concluded that trackway measurements were able to describe the gait pattern in walking cows under dairy farm conditions. However, considering the relatively high within-test variation in gait, several strides should be used to obtain a representative gait pattern.
... Also SF differed significantly among the agegroups: we found a decrease in SF. An explanation for such results could be the phenomenon of growth, the same results were found by others in, respectively, 4 Standardbred trotters on the track at age 4 years and again 3 years later (Drevemo et al. 1980) and in 143 French Trotters on the track age 2-7 years (Leleu et al. 2004). In our experiment, there was no effect of age/training on RF. ...
A close relationship between limb and respiratory rhythms has been shown in clinically healthy galloping horses due to mechanical constraints in the thoracic region. This synchronisation leads to a 1/1 ratio between stride frequency (SF) and respiratory frequency (RF) during galloping. Very little is known about locomotor-respiratory coupling (LRC) during fast trot.
To investigate stride and respiratory rates during a standardised exercise test on the track in Standardbred Trotters.
Forty-four French trotters age 2-10 years performed a standardised exercise test consisting of three 3 min steps at constant speeds. Speed (V) of exercise varied between 500 and 750 m/min. Variables measured during exercise: SF, heart rate, RF using a microphone between the nostrils, blood lactate concentration. Physiological variables V4 and V200 were calculated and race performance index recorded.
There was no age-related difference in RF or in LRC. Two LRC strategies were found: around 1/1 ratio and 3/2 ratio between SF and RF, respectively. A relationship between SF/RF ratio and physiological parameters showed a higher LRC in good performers because of a lower RF during submaximal and maximal exercise.
RF is significantly lower and LRC significantly higher in good compared to poor performers.
Investigation is required to ensure that the breathing techniques of trotters may be used in the selection process of racehorses.
... However, in sound horses both kinematic and ground reaction force (GRF) variables are quite stable at constant speed. It has been suggested that 3-5 strides are sufficient for kinematic (Drevemo et al. 1980) as well as GRF (Schamhardt 1996) analysis. Low variations in the present material are also strongly suggested as there is very little difference in average stance duration from the original data used for GRF evaluations (Roepstorff et al. 2002). ...
No data exist on the GRF-kinematics relation due to changes caused by equestrian interventions.
Through the judicious use of draw reins the rider can influence the kinematics of the horse to meet stated goals of dressage training. Relating the results to previously published kinetic data of the same experiment implies a possible relationship between kinetics and kinematics.
The kinematics of 8 sound Swedish Warmblood horses were measured whilst the horses were being ridden with and without draw reins. Three conditions were evaluated: 1) draw reins only (DR), 2) combination of draw reins and normal reins (NR+DR) and 3) normal reins only (NR).
Head and neck angles were significantly decreased by the draw rein but 4-5 times more so for DR when with NR+DR. The forelimb position at hoof lift-off was significantly more caudal with DR. In the hind limb the hip joint extended more quickly and the hock joint flexed more with NR+DR than with NR. Compared to DR the hip joint angular pattern was not significantly different, but the pelvis was more horizontal.
Riding with a draw rein can have significant influence on the kinematics of the horse. Some of the observed changes can be coupled to changes in kinetics. The hock joint angle seems to be a fairly reliable indicator of load on the hind limb and the angle of femur appears important for hind limb propulsion, when considered in conjunction with the orientation of the pelvis.
These findings are important for riders and trainers, as kinematic changes are what trainers observe. It is thereby important to ascertain which kinematic changes are consistently coupled to changes in kinetics in order for trainers to be able to judge correctly the success of intended goals. Further studies are warranted to validate and confirm suggested relationships between kinetics and kinematics.
... Analysis of a relatively small number of strides can therefore be considered representative for the gait pattern. It has been suggested that 3-5 strides are sufficient for kinematic (Drevemo et al. 1980) as well as GRF (Schamhardt 1996) analysis. Low variations is also strongly pointed towards in the present material as there is very little difference in average stance duration from the original data used for GRF evaluations (Roepstorff et al. 2002) to the reduced data in the present work, practically no difference in the fore limb (87,27 ms in both data series) and only 0,35 ms in the hind limb. ...
Ett ofta angivet syfte vid olika former av träning inom både hoppning och dressyr är att påverka hästens rörelser och förmå hästen att bära mer vikt på bakdelen och avlasta frambenen. Om och hur detta sker har dock knappt alls utvärderats med objektiva metoder. Effekter av träning över längre tid har studerats med avseende på förändringar i gångartsmönstret men då har kraftmätningar har inte inkluderats. I andra studier har man konstaterat att tyngden av en ryttare ökar belastningen på hästens ben, och då särskilt frambenen. Endast en av dessa studier har dock givit indikation om att ryttaren har möjlighet att påverka belastningsförhållandena. En studie av gramantygelns inverkan på belastningsfördelningen mellan fram- och bakben kunde visa att gramantygel i kombination med vanlig tygel gav signifikant ökad såväl vertikal som propulsiv impuls i bakbenet (Roepstorff et al. 2002). Samtidigt gjordes även synkroniserade kinematiska registreringar. Från dessa har i följande arbete data från understödsfasen har valts ut och analyserats. Syftet är att utvärdera eventuella kinematiska effekter av gramantygeln samt att om möjligt upptäcka samband mellan kinetik och kinematik.
Analys av kinematiska data visade att gramantygeln förändrade hals- och nackvinklarna. Påverkan på halsvinkeln var mer än tre gånger så stor med graman som enda tygel jämfört med i kombination med vanlig tygel. Frambenet fördes snabbare med graman, både ensam och i kombination, men signifikant ökad retraktion sågs enbart med endast graman. Kombinationen av tyglar gav ökad sträckning av lårleden under andra hälften av understödet. Graman som enda tygel gav inte samma förändring. Lårledvinkeln kan därför antas vara kopplad till bakbenets propulsiva impuls, då denna förändrades på likartat sätt. Med gramantygel som komplement till vanlig tygel sågs även ökad flexion av has, knä och höft under första delen av understödet samt ökad flexion av hasen och minskad lutning av bäckenet i understödsfasens mitt. Motsvarande mönster kunde ej ses med endast graman. Det kan tyda på att gramantygeln, men endast i kombination med vanlig tygel, kan bidra till ökad upplagring av elastisk energi i bakdelen, vilket sedan kan utnyttjas för ökad propulsiv kraft i slutet av understödet. Förändringarna kan också ha samband med ökad vertikal belastning av bakdelen.
Racehorses competing in short (i.e., ‘sprinters’), middle- or longer-distance (i.e., ‘stayers’) flat races are assumed to have natural variation in locomotion; sprinters having an innately shorter stride than stayers. No study has objectively tested this theory. Here, racehorses (n = 421) were categorised as sprinters, milers or stayers based on known race distance (n = 3269 races). Stride parameters (peak length and frequency) of those racehorses were collected from prior race-pace training sessions on turf (n = 2689; ‘jumpout’, n = 1013), using a locomotion monitoring device. Pedigree information for all 421 racehorses was extracted to three-generations. In training, sprinters had a shorter stride of higher frequency and covered consecutive furlongs faster than stayers (p < 0.001). Relatively short or longer stride did not predict race success, but stayers had greater race success than sprinters (p < 0.001). Peak stride length and frequency were moderately heritable (h2 = 0.15 and 0.20, respectively). In conclusion, differences in stride were apparent between sprinters and stayers (e.g., shorter stride in sprinters) during routine training, even after accounting for their pedigree. Objective data on stride characteristics could supplement other less objectively obtained parameters to benefit trainers in the appropriate selection of races for each individual racehorse.
The unwanted horse problem is the most serious issue confronting the equestrian industry. Thus, it is recommended that retired racehorses switch to become saddle horses for ‘the second life of a racing veteran’ because training and using retired Thoroughbred racehorses as saddle horses is the most cost-effective option. The current study aimed to analyze the effects of saddle horse conversion training on gaits of retired Thoroughbred racehorses. Our study included 12 retired Thoroughbred racehorses. These Thoroughbred racehorses performed the retraining 20–50 min a day, five times per week for three months. There are some critical findings in this study. The results show that the decreased stride length of each foot decreased the displacements of the center of mass and the center of the head. In addition, after retraining, there was a significant decrease in the head–neck angle and displacement between the center of the head and the center of the neck. These changes in the horse’s movements mean that the habitual movements for racing are gradually changed to optimal movements for a saddle horse.
The objective was to evaluate the effects of gymnastic training on stride characteristics of walk and trot in therapy horses carrying riders of different weights. Eighteen horses used for therapeutic riding 5 days/ week were randomly divided into 2 groups. Nine horses performed gymnastic (GYM) exercises after therapeutic riding on 4 days/week for 3 months, 9 horses did no additional exercises (SED). On days 0 and 90, an inertial sensor mounted to the girth on the ventral midline was used to evaluate stride characteristics when horses were ridden at walk (1.3 m/second) and trot (3.0 m/second) by able-bodied riders representing rider: horse body weight ratios (BWRs) 15%, 20%, and 25%. On day 0, the measured variables did not differ significantly between sedentary (SED) and GYM groups, but on day 90, the following statistically significant results were found: GYM-trained horses had higher regularity for all BWRs at walk and 15% and 20% BWRs at trot. Higher stride symmetry was found in GYM-trained horses carrying 25% BWRs at walk and all rider weights at trot. Dorsoventral displacement was higher in GYM-trained horses when carrying 20% and 25% BWRs at walk and 25% BWRs at trot. Dorsoventral power was lower in SED-trained versus GYM-trained horses carrying 15% BWR at walk and 20% BWR at trot. A more regular and symmetrical stride with a larger range of dorsoventral trunk motion is likely to provide a better therapeutic riding experience.
A method for analysing the movements of the forelimbs from the dorsal (frontal) view in horses was to establish. 15 horses without any clinical signs of lameness, but with a deviation of the regular conformation of the forelimbs, were filmed with a Kodak motion corder analyzer SR 500 (250 frames/sec.) while walking on the treadmill. To analyze the films the WINanalyze-Software was used. Characteristic curve diagrams (y-t-diagrams) for horses were developed, which show the movement of marked points of the distal limbs (hoof wall, pastern joint, fetlock joint and proximal metacarpal bone). These y-t-diagrams were used to differentiate a plane, lateral or medial first ground contact. Additionally the difference of the fetlock angle (Δα) was determined. It is used to describe the difference of the angle between the limb-and toeaxis. The correlation between the difference of the fetlock angle and the first ground contact was highly significant.
In orthopaedic patients, optimizing limb movement by hoof trimming or shoeing is very important. To do this, exact assessment of the forelimb movements is essential. Since the human eye cannot distinguish all motions of the limbs, a two dimensional horse gait kinematographic analysis method using the frontal view has been tested in this study. For this purpose 28 sound horses were recorded at a walk on the treadmill using a high frequency video camera (KODAK motion corder analyzer SR 500, 250 fps). The video clips were analysed using the PROTrack®-Sofware and Microsoft Excel®. Characteristic motion curves of markers placed on the limbs were established. Using this method we could determine the duration and the length of the stride, of the stance and of the swing phase. Based on the motion curves it could be determined whether the limb is being led toward or around the controlateral limb during the swing phase. In conclusion the two dimensional system used in this study was able to illustrate the forelimb movements during the swing phase precisely. This system should be clinically useful for the characterisation of limb movements in horses with irregular forelimb conformation.
Limb contact variables of the gaits of dressage horses were determined for competitors at the 1988 Seoul Summer Olympic Games in the team and individual dressage competitions. Two 16-mm motion picture cameras filming at 100 fps were aimed perpendicular to the plane of equestrian motion along the HXF and MXK diagonals of the standard dressage arena. Eighteen competitors in team dressage were filmed during the Grand Prix test while executing the extended walk, extended trot, and left lead extended canter. Fifteen horses selected as finalists for individual dressage medals were filmed during the Grand Prix Special test executing the extended trot, one-stride canter lead changes, two-stride canter lead changes, and the left lead extended canter. Velocities of the extended walk, extended trot, and extended canter were positively related to stride length. Velocities of the Grand Prix extended walk and Grand Prix Special extended trot were positively related to stride frequency. Limb contact patterns of the extended walk stride appeared to have relatively little importance in scoring. Certain characteristics of the extended trot and extended canter were strongly related to scores attained in Grand Prix Special dressage tests, with highest scores achieved by horses with the longest, fastest strides. For canter strides involving lead changes, no limb contact variables were detected that were significantly related to scores. This study provided the first objective documentation of the limb contact patterns of the walk, trot, and canter of world-class dressage horses.
In this study on earlier developed tool, consisting of a high-speed video camera with appropriate analysis software, is used to analyse limb conformation and hoof landing characteristics as seen from the frontal plane in horses walking an a traedmill. Gait analysis was performed with an s-VHS camera and a high frequency videocamera (KODAK motion corder analyser SR 500, 250 fps) using an analysis software (WINanalyse®, Cie. Mikromak, Erlangen; ProTrack*, Cie. Prophysics, Zürich and Microsoft Excel®). The study is conducted in 2 study populations. Population A (n= 15) was filmed before, during and after farrier treatment in order to assess limb conformation and hoof landing in a frontal view. In study B (n = 28) the same was done, but in this population swing phase characteristics were measured as well. A comparison was made between visual and computer based analysis of the videos. Results were that the computer based cinematographic method allowed for more detailed judgement than visual observation, even if slow motion is used. During the stance phase, the correlation between an uneven first ground contact of the hoof and the horizontal movement of the fetlock joint at the beginning of the stance phase was highly significant. Most horses showed a lateral landing. Trimming and shoeing was performed on the basis of the slow-motion films recorded with the s-VHS camera but improved the type of landing only insignificantly. During the swing phase, all horses had an irregular limb motion in the front view. The segment near the carpus showed predominantly a monophasic movement, arching towards the outside, away from the contralateral limb. In contrast, the hoof and the fetlock joint showed several oscillations in their motion pattern with an overall movement arching inwards, towards the contralateral limb. The conformation of the forelimbs had no influence on the way of landing but tended to influence the movement of the toe during the swing phase. In particular in horses with a base-narrow conformation the anatomic variations of the digits affected the swing phase of the hoof. Horses with a broken limb-axis had significantly more and larger latero-medial out-of-plane movements than did other horses. The trajectory of the proximal part of the forelimb affected the way of landing significantly. In this kinematographic analysis we were able to demonstrate new and more complicated correlations between the conformation of horses, the limb motion during the swing phase and the way of landing of the hoof than we previously expected.
The aim of this study was to compare the effect of the horse on various performance tests calculated for free jumping parameters. Free jumping parameters were measured on the basis of video image analysis. Three groups of horses were compared: 141 stallions on the 11-month test (744 jumps), 50 stallions on the 8-month test (301 jumps) and 43 stallions on the 100-day test (221 jumps). Linear measurements of taking off and landing distances, height of limb lifting above the obstacle, height of elevation of “bascule points” and position of the head were measured. The statistical model was comparable for all tests including the random effect of the horse, fixed effects of the test, height of the obstacle and successive number of the jump. Repeatability on the 11-month test was high for taking off, landing and bascule parameters and reached values from 0.50 to 0.60. Repeatability of heights of limb lifting in the 11-month test was lower, but at the same value of about 0.3 for front and hind limbs. In the test of the same duration but for horses selected as the best ones—the repeatability of limb lifting was higher for front limbs and almost the same for hind limbs. Repeatability of the parameters that characterised the length of the jump and the bascule of the horse was higher in the test for the best horses and reached 0.82 for landing and 0.66–0.77 for bascule points. Repeatability of almost all jumping parameters reached highest values in the group of the best horses with longer training.
Limb contact variables of the gaits of superior dressage horses were determined for competitors at the 1988 Seoul Summer Olympic Games in the finals of the Individual Dressage competition. Two 16-mm motion picture cameras were aimed perpendicular to the plane of motion along the HXF and KXM diagonals of the standard dressage arena, and filmed at 100 fps. Nineteen of the horses selected as finalists for individual dressage medals were filmed during the Grand Prix Special test executing one-stride canter lead changes, two-stride canter lead changes and the left lead extended canter. Velocities, stride lengths and stride durations were 7.03±.07 m/s, 4.15±.05 m and .592±.004 s for the extended canter. Across all stride frequencies, score was optimized with extended canter strides of the greatest length, with no upper limit detected to optimal stride length. Canter strides with lead changes had lower velocities, shorter strides and longer durations than strides without a lead change, with velocities, stride lengths and stride durations, respectively, of 3.36±.05 m/s, 2.08±.04 m and .617±.003 s for one-stride canter lead change strides; 3.65±.07 m/s, 2.21±.04 m and .605±.003 s for pre-change canter two-stride lead change strides; and 3.95±.07 m/s, 2.44±.04 m and .621±.004 s for post-change canter two-stride lead change strides. This study provided the first objective documentation of the canter limb contact patterns of world-class dressage horses.
Movement analysis techniques allow objective and quantitative assessment of kinematic gait analysis. Consistent repeatability of the kinematic data is essential for such assessments. This study investigated whether the repeatability of a standardised Equinalysis Elite gait analysis system is sufficient to allow its use in clinical evaluation of equine lameness with reliable documentation of individual locomotion patterns. The extent to which examinations on different days affected the results when a standardised protocol was used was investigated. The repeatability of distal limb kinematics in 9 sound horses over 3 successive days at 1 location was investigated. Measurements were performed at the examination area, for 3 motion cycles at the walk and trot, in each direction per day. Skin markers were placed on the lateral aspect of the coffin joint, forelimb fetlock joint, hindlimb fetlock joint, carpus, tarsus, elbow and stifle at clipped sites marked with a permanent marker. The inter-day repeatability of angular measurements of the carpus, tarsus, forelimb fetlock and hindlimb fetlock joints was determined. A low degree of inter-day repeatability was found with statistically significant (P=
A standard terminology for the description of equine jumping technique is proposed. To facilitate comparisons between strides, it is recommended that the stride be maintained throughout the approach, the take off, the jump, the landing and the move off. The stride in which the horse jumps the fence, called the jump stride, is subdivided into the take off, the jump suspension, and the landing. Take off is the period from impact of the first hind limb until lift off of the last hind limb in the jump stride. The jump suspension is the period from lift off of the last hind limb at take off until impact of the first forelimb at landing. Landing is defined as the period from impact of the first forelimb after the jump suspension until the next impact of the trailing hind limb. The stride before the jump stride is called approach stride 1. It is preceded by approach stride 2, approach stride 3, and so on. The strides following the jump stride are called move off strides 1, 2, 3 and so on in chronological order. An advantage of this nomenclature is its flexible nature, allowing for the inclusion of a variable number of strides on either side of the fence. When a horse takes 3 strides or less between 2 successive fences, the strides are known as intermediate strides 1, 2 and 3, counting from the first fence to the succeeding one. The application of the proposed terms is illustrated using data from a horse jumping a vertical fence 1.55 m high.
Little information is available about gait characteristics and the level of performance in racehorses. The aim of that cross-sectional experiment was to study the relationships between some locomotor variables and the level of performance of trotter racehorses. A total of 104 horses from 3 to 7 years old performed a four-step locomotor test on the track with an accelerometric device: Equimetrix™. The population was divided into two groups on the basis of their official performance index: Index of TRot (ITR). These two groups were: an elite performers group (n=52) and a medium performers group (n=52). Locomotor variables: stride frequency, stance and propulsion durations, stride length, symmetry, regularity, dorsoventral, longitudinal and lateral activities were calculated at four different speeds (8.5, 11, 11.7 m/s and maximal speed). The variables were compared between two performance groups by an analysis of variance. The main results indicated that elite performers presented significantly higher stride frequency, longer stance and propulsion durations at submaximal and maximal speed. In conclusion, biomechanical characteristics of trotter racehorses, such as stride frequency and propulsion duration, might be useful criteria to quantify gait efficiency in trotter racehorses.
The assessment of the effect of race training on the locomotory apparatus can be confounded by tissue responses to the increasing training load, such as dorsal metacarpal disease. The aim of this paper was to examine the changes in gait during the early stage of race training in a cohort of 19.2-year-old Thoroughbreds, 11 of which had previously been exposed to spontaneous pasture exercise and also to preconditioning exercise from an early age (CONDEX), and the remainder had been exposed to only spontaneous pasture exercise (PASTEX). Data were collected 52, 60, 77, 109 and 176 days after the horses had entered the racing stable. At each examination, the horses were trotted in-hand on a hard asphalt surface, and kinematic data were collected. The horses trotted slowest on the first examination day, with a significantly longer and slower stride and associated percentage stance time. On day 77, the CONDEX horses trotted faster, had a longer stride length and achieved mid-stance earlier than the PASTEX horses. Across both groups, the introduction of galloping was associated with a significant reduction in stride duration (0.69 ± 0.01 vs. 0.66 ± 0.01 s, P = 0.001), stride length (2.49 ± 0.03 vs. 2.38 ± 0.02 m, P = 0.004) and stance duration (27.3 ± 1.0 vs. 32.0 ± 1.0%, P = 0.001). The changes in gait appeared to be associated with the introduction of galloping and the associated tolerance of the CONDEX group to the musculoskeletal loading.
Back dysfunction is an important reason for impaired performance in sport horses. Limb movements influence the movements of the back and factors affecting the limbs may therefore affect the movement of the back. The aim of the study was to investigate the influence of weighted boots on the fore- and hind limbs on the movement of the back. The back kinematics of eight horses was studied at the walk and trot on a treadmill. The ranges of movement (ROM) of the back were compared intra-individually, using Wilcoxon matched pairs test, when the horses moved with and without weighted boots on the fore- and hind limbs, respectively. Differences were considered significant at P<0.05. Weighted boots on the hind limbs increased the ROM for dorsoventral flexion and extension in the lumbar back at the walk and decreased the ROM for lateral bending at the thoracolumbar junction at the trot. Weighted boots on the forelimbs decreased the ROM for lateral bending at the withers at the trot. Knowledge of the effect of weighted boots on the back movement is useful in training and rehabilitation of sport horses. Weighted boots on the hind limbs at the walk may induce strengthening of the flexors of the lumbar back and increase the flexion–extension of the lumbar back under controlled conditions.
The aim of this study was to identify the effect of training stage, height of the obstacle and successive number of jump on young stallions' linear jumping parameters with and without rider. Investigations were based on filming of free jumping and jumping with rider during regular stallion work on the 11-month performance test. Horses jumped through the spread obstacle (doublebarre) with constant width of 90 cm and heights of 100, 110 and 120 cm. Taking-off distance, landing distance, heights of legs above obstacle and bascule of horse silhouette were measured using manual programme for video image analysis. Almost all parameters measured with and without rider were training dependent. The only parameters not affected by training were heights of hind limbs above obstacle, which were also not affected by height of obstacle in observations of more trained horses by free jumping and less trained horses with rider. Jumping parameters were not influenced by successive number of the jump by all parameters with rider and parameters of length of the jump in free jumping. On the basis of received results, it could be concluded that evaluation of jumping skills in free jumping and jumping with rider should be based on different criteria.
Some basic stride characteristics of race trotters were measured by means of an accelerometric device during a locomotor test in order to find stride parameters, predictive for race performance. Twenty-four horses of various racing abilities were tested on the same flat racetrack. They were allocated to 3 groups according to their performance indices. The locomotor test consisted of 3 stages at increasing speeds and the third stage was performed at maximum individual speed. Basic stride variables were extracted from the acceleration data using specific procedures including built-in functions of a data analysis programme. Some significant relationships were found between stride characteristics measured at maximum individual speed and race performances obtained during the year. The maximum speed and stride length were positively correlated (r=0.60 and 0.45, P<0.05) with the performance index. The maximum stride frequency was negatively correlated with the best time (r/-0.46, P<0.05). The maximum speed, stride frequency, contribution of stride frequency to the speed and stride length were greater in the high performance group than in the other groups (P<0.05). The symmetry and regularity of the trot were not significantly related to the performance. A good performer should have a high maximum speed which is mainly produced by a high stride frequency greater than 2.40 strides/s. The accelerometric device was efficient for testing trotters and could be used to predict potential performance.
Fourteen 2-year-old Standardbred trotters, born, raised and trained at the same establishment performed maximal exercise on a track over a distance of 1000 m. Blood samples for plasma lactate (PLA) analyses were obtained from the jugular vein immediately after exercise. Muscle biopsies from m. gluteus medius were taken and analysed for fibre type composition (I, IIA, IIB) and enzyme activities representing oxidative (citrate synthase (CS), 3-OH- acyl-CoA dehydrogenase (HAD)) and glycolytic (lactate dehydrogenase (LDH)) capacity. Stance time (ST), stride length (SL) and velocity were determined from high speed films (250 frames/s). Simple linear regression analysis was used to describe relationships between lactate response, muscle characteristics and basic kinematic variables. Significant positive correlations were found between PLA/IIB and negative correlations between ST/IIB, SL/PLA, ST/PLA. No relationships were observed between CS, LDH or HAD and PLA, IIB or the kinematic parameters. The results indicate that young Standardbred trotters with a low percentage of type IIB fibres perform maximal trotting with a low lactate production and long stride length and stance time.
The objective of this study was to determine the effect of insemination volumes on embryo recovery in mares. Sixty-two light-horse mares were randomly assigned to 1 of 3 insemination treatments as they exhibited estrus. Mares were artificially inseminated with 100 × 106 progressively motile spermatozoa (pms) extended in 10, 100 or 200 ml of dried skim milk extender (E-Z Mixin). Embryo-recovery attempts were performed 6 or 7 days post-ovulation.6 Due to recovery of a low number of embryos, a second experiment was conducted with the same mares using a greater number of progressively motile spermatozoa (250 × 106 pms) suspended in either 10 or 100 ml of E-Z Mixin extender. In Experiment 1, there was no difference (P>0.05) in numbers of embryos recovered between mares inseminated with 10 (40%) and 100 ml (10.0%) of extender, nor was there a difference (P>0.05) between mares inseminated with 100 (10.0%) and 200 ml (0.0%). However, there was a significant difference in embryos recovered between mares inseminated with 10 (40.0%) and 200 ml (0.0%) (P<0.001). In Experiment 2, there was a highly significant difference between mares inseminated with 10 ml (70.6%) compared to 100 ml (13.0%) of extender (P<0.0005). It was concluded that insemination volumes of 100 ml or 200 ml were associated with lower fertility than with a 10 ml volume. This may have been due to low sperm concentrations and should be examined in future studies.
The owners and managers of an equine packing plant in Illinois were interviewed, and their operation was observed in order to determine the nature of the horse meat trade, and to assess the residual value of horses as meat animals. All meat products were exported for human consumption in the European and Japanese markets. Belgium, France and The Netherlands were the primary consumer nations.Prices paid for horses in 1988 ranged from $.15 to $.47 per lb. of live weight and depended on size, muscle thickness and body condition. Seasonal variation in prices was found. The highest prices were paid for horses during the period of January through April. The lowest prices were paid for horses during October and November.The packing plant impacted the Illinois and surrounding Midwest horse industry by supplying a market for low-quality horses. In 1988, this company purchased 25,000 horses with little value other than as meat animals. It also provided employment to 85 full time workers at an average wage of $6.00 per hour. In addition, 5 commission buyers and 6 independent buyers gained employment as suppliers of horses to the plant.
General mathematical models are presented to be used in equine kinematic gait analysis for the correction of the biological error that is caused by sliding of the skin over the underlying bony landmarks. Ten sites in the front limb and 8 in the hind limb were investigated. In the distal parts of the limbs a linear relationship with the angle of the adjacent joint was found. The more complex pattern in the proximal parts of the limbs could be satisfactorily represented by truncated Fourier series. Analyses were principally done in the Dutch Warmblood horse, but investigations in other breeds were carried out to verify the general applicability of the models. Skin displacement appeared to be negligible in the lower parts of the limbs, but reached large values in proximally located sites such as the caudal part of the greater trochanter of the femur. It is concluded that skin displacement in equine gait analysis may account for major errors in applied biomechanical research and therefore should be corrected, although it may be of less importance for clinical applications.
Toe weights are applied to influence the stride characteristics of trotters. The quantitative effect of 88‐g toe weights on the stride characteristics of Standardbred trotters was evaluated in a kinematic study using a CODA‐3 analysis system. Six trotters were studied at a speed of 11 m/s on a treadmill. Temporal gait variables, joint angles, and the trajectories of the forelimb hoof were calculated.The stride patterns of the individual trotters were assessed by a judge and compared to the CODA‐output. Those trotters with poor flexion of the carpal joint during the swing phase or with insufficient knee action responded with better carpal flexion and more knee action when toe weights were attached.No effect of toe weights on the protraction of the forelimb could be demonstrated. Stride length, stride duration, and the relative duration of the stance and swing phase as a percentage of the stride did not respond to toe weights. It is concluded that toe weights can be useful in Standardbred trotters, but their effect depends on the individual gait pattern.
The aim of this study was to assess whether locomotion parameters obtained by measurements of cow trackways are reliable and sufficiently sensitive to describe locomotion in non-lame and lame dairy cows on different floors. Thirty-two non-lame cows were used to study the reliability of the trackway measurements. The cows were tested twice over three weeks and measurements from four consecutive strides were used during each test session. To study the effect of different floors on locomotion, 25 non-lame cows and eleven cows with different lameness degrees were tested on five different surfaces: solid and slatted concrete, both with and without 20 mm thick elastic rubber mats, and wet, compacted sand. The reliability of the measurements varied from moderate to low, with measurements relating to inter-limb coordination being most inconsistent. The slippery slatted concrete floor caused restricted locomotion in so far as the strides were significantly shorter here than on all the other floors. Use of yielding rubber mats resulted in a locomotion more similar to that on the sand path. Lameness had an effect on shortening strides and steps, but in most cases the animals’ reaction to different floorings was similar in lame and healthy cows. Step asymmetry due to lameness was decreased when cows walked on the soft surfaces. It was concluded that a trackway measurement system is a suitable method to use in field locomotion studies and that the system is useful in identifying differences in kinematics on different floor types. Since there is a relatively high inconsistency in cow walking it is beneficial to use measurements of several strides to obtain a representative gait pattern.
The effect of pulsed radio frequency therapy (PRFT) was evaluated on seven ponies with no arthritis and in 28 ponies in which arthritis was created using intra-articular amphotericin B to induce synovitis in the right middle carpal joint. The ponies were divided into five treatment and two control groups. Two levels of arthritis were created and two dosage levels of PRFT were evaluated. The effect of PRFT on arthritic and nonarthritic joints was measured by comparing synovial fluid parameters, the degree and duration of lameness, the range of carpal motion, and carpus circumference, for treated and untreated groups. Lesions seen radiographically, at gross pathology, and by histopathology were also compared between the treated and control groups. In the ponies with a mild form of induced arthritis, PRFT significantly (p less than 0.05) reduced the severity and duration of lameness, swelling of the carpus, and the severity of gross pathological and radiographic changes. In these ponies the synovial acid phosphatase levels were lower, the mucin clot quality was superior, and the synovial protein levels were lower for the ponies receiving PRFT as compared to the arthritic ponies receiving no treatment. A dose response effect was evident. In ponies with a slightly more severe form of arthritis, PRFT was evaluated at one dosage level. The treated ponies were significantly improved over the untreated ponies with respect to carpal range of motion, degree of lameness, carpus swelling, and radiographic lesions. No deleterious effects were noted when normal, PRFT treated, middle carpal joints were compared to contralateral untreated, normal joints. It was concluded that significant beneficial effects resulted when affected ponies were treated with PRFT.
Examination for lameness remains the most important component of the clinical evaluation for poor performance. Although conventional examinations can be used to diagnose many causes of lameness, treadmill video gait analysis and dynamic hoof balance evaluations have proved to be useful not only for evaluating lameness but also for maintenance of long-term soundness. Treadmill lameness evaluations offer a major advantage compared to conventional evaluations because of the stationary position of the exercising horse relative to the people performing the examination. Lameness is suspected if asymmetric motion is observed or asymmetric sounds of the feet contacting the tread surface are heard during the treadmill evaluation. Localization of lameness to the front or hind legs is the first step in the treadmill gait analysis protocol. In trotting and pacing horses, asymmetric movements associated with foreleg lameness generally are confined to the front end. In contrast to the pacing gait, asymmetric movements associated with hindlimb lameness can involve both the front and rear of the horse at the trot. The evaluation is continued to determine which side of the horse is abnormal. Viewed from the front, horses with primary forelimb lameness appear to have an asymmetric downward rotation of the torso, head, and neck away from the stiffer lame front leg toward the flexed normal leg as it contacts the tread surface. The lame hind leg can appear to be stiff relative to the opposite normal leg. This results in uneven side-to-side oscillations of the pelvis rotating away from the abnormal stiff-appearing hind leg toward the normal, flexed hind leg as it contacts the tread surface. Both front- and hind-leg lamenesses cause dissociation of the normal foot-fall sequence, resulting in the alteration of the normal two beat gait at the trot or the pace to a three-beat gait. The final step of the lameness examination involves the use of diagnostic regional anesthesia to determine the anatomic location of the lameness. Treadmill video gait analysis can be used to evaluate differences in the horse's gait before and after each anesthetic block. Optimal foot balance during exercise is critical for long-term maintenance of musculoskeletal soundness. Combining slow-motion video gait analysis with treadmill exercise provides an excellent method for evaluating hoof balance at a variety of speeds. Optimal hoof balance can be achieved by using the technique of successive trimming and re-evaluation. The principles of hoof balancing include establishing dorsopalmar or dorsoplantar hoof balance.(ABSTRACT TRUNCATED AT 400 WORDS)
High-speed cinematography with computer aided analysis was used to study equine hindlimb kinematics. Eight horses were filmed at the trot or the pace. Filming was done from the side (lateral) and the back (caudal). Parameters measured from the lateral filming included the heights of the tuber coxae and tailhead, protraction and retraction of the hoof and angular changes of the tarsus and stifle. Abduction and adduction of the limb and tarsal height changes were measured from the caudal filming. The maximum and minimum values plus the standard deviations and coefficients of variations are presented in tabular form. Three gait diagrams were constructed to represent stifle angle versus tarsal angle, metatarsophalangeal height versus protraction-retraction (fetlock height diagram) and tuber coxae and tailhead height versus stride (pelvic height diagram). Application of the technique to the group of horses revealed good repeatability of the gait diagrams within a limb and the diagrams appeared to be sensitive indicators of left/right asymmetries.
Standardbred pacers have been studied under race conditions to describe the gait of the pacer, and to determine relationships between stage of the race, finish order and selected gait kinematics. Overlap increased with the stage of the race while pacing speed decreased marginally for low order pacers and increased for high order finishers. High order finishing pacers appear to have greater stance and stride lengths than do low order finishers. Pacers could be separated into low order and high order groups on the basis of their movement patterns. High order pacers exhibited greater ranges of limb motion than did low order finishers.
A technique enabling simultaneous visualisation of skin and underlying bony structures in the walking horse was used to quantify skin displacements on the lateral surface of carpal, tarsal and fetlock joints. The technique employed implanted light-emitting-diodes (LEDs) for marking the bone, and self adhesive spot labels for marking the overlying skin. Photographic recordings were made. Skin displacement was measured in six Dutch Warmblood horses. Mean total displacements and mean displacement per degree of change of joint angle were calculated. Displacements at the level of the fetlock joints appeared to be generally small (less than or equal to 2 mm), but displacements up to 2 cm were measured in the distal tibia. Displacements of this magnitude are of importance for the interpretation of results obtained by modern gait analysis techniques.
The use of markers placed over the tuber coxae on each side of a horse to aid identification of the relative movement of these structures at the trot, for teaching and research purposes, is described. In each case of hindleg lameness studied, the tuber coxae on the lame side showed a consistent increase in vertical displacement relative to that of the contralateral limb, and a characteristic pattern of movement throughout the stride irrespective of the site or cause of pain.
Gait analysis can play an important role in exercise physiology, racetrack ergonomics, lameness prophylaxis, and assessment of performance potential in racehorses. This article concentrates on the methods used for gait analysis and considers some basic data on the different gaits of the horse.
A review of the literature about equine locomotion and biomechanics is presented to summarise available knowledge and provide perspective to current and proposed research programmes. It is evident that much past research has failed to provide sufficient information on basic principles of these two disciplines and that information is now required before progress can be made on more applied research topics. However, useful contributions have been made in gait typology, analysis of racetrack surface and design and limb kinetics, kinematics and coordination.
En partant d'un passage en revue de la littérature concernant la locomotion équine et la biomécanique, on fait le point des connaissances et l'on ouvre des perspectives sur les recherches en cours ou projetées. Il est évident que pour la plupart les recherches passées n'ont pas réussi à fournir des informations suffisantes sur les principes fondamentaux de ces deux disciplines; cette information est aujourd'hui nécessaire pour permettre une recherche élaborée. Cependant des contributions utiles ont été apportées dans la typologie des allures, dans l'etude et le profilage des pistes, dans la cinétique, la cinématique et la coordination des membres.
Eine Literaturübersicht über die Fortbewegung und die Biomechanik des Pferdes soll das zur Verfügung stehende Wissen zusammenfassen und eine Grundlage bilden zur Beurteilung gegenwärtiger und vorgeschlagener Forschungsprogrammen. Es ist evident, dass ein grosser Teil der früheren Anstrengungen nur ungenügende Informationen über die grundlegenden Prinzipien der beiden Disziplinen geliefert hat. Bevor man Fortschritte auf angewandtem Forschungsgebiet erwarten kann, muss die fehlende Information erarbeitet werden. Immerhin stellen nützliche Beiträge zu einer Typologie der Gänge, zur Beschaffenheit von Rennbahnoberflächen, zur Rennbahnplanung und zur Kinetik, der Kinematik und Koordination der Gliedmassen schon zur Verfügung.
A survey of a western Canadian racetrack determined the superelevation and transition curves to be less than the cited design standards. High-speed cinematography was used to film seven Standardbred pacers as they proceeded around one curve of the track at racing speed and for each horse 19 temporal stride parameters were obtained from these films using a film analyzer system. Average velocities were calculated and the mean stride length was found to vary from 5.08 m to 5.77 m. In all frames analyzed the hind foot was observed to contact the track surface prior to the ipsilateral forefoot and all horses displayed significant (p less than 0.05) contralateral asymmetry of some temporal stride parameters. Fifteen temporal stride parameters were significantly different (p less than 0.05) when compared between horses but only three temporal stride parameters were significantly different (p less than 0.05) when their values were compared between segments of the curved portions of the track. It is suggested that temporal gait asymmetry should not be used to judge the standards of racetrack design.
A treadmill for equine locomotion analysis is described and its potential considered for locomotive research and clinical investigation. The treadmill comprised an endless belt driven by a hydraulic motor at various speeds up to 14 m/sec and the direction of belt movement was reversible. The carrying side of the belt ran over a steel‐concrete table which acted as a flat support. The belt itself consisted of a steel base on to which was glued a rubber belt and the surface was covered with a layer of coir matting which permitted some forward sliding of the landing hoofs simulating the conditions on an ordinary track. The treadway could be inclined up to 10° in the longitudinal and 7.5° in the transverse direction. To minimise the risk of injuries a special emergency stop system was installed. Horses adapted well to exercising on the treadmill, even without any previous experience. A good correlation was found between the gait repetivity on the racetrack and that displayed on the treadmill. One horse recorded both on the racetrack and on the treadmill showed significantly shorter strides on the treadmill but this did not invalidate the treadmill as a useful research tool in the study of equine locomotion.
Résumé
On dócrit un tapis roulant pour l'analyse de la locomotion équine. Les possibilités de cet appareil sont envisagées tant pour l'étude de la locomotion que pour la recherche clinique. L'appareil comporte un tapis sans fin entraîné par un moteur hydraulique à des vitesses variables jusqu'à 14 mètres/seconde; la direction du mouvement est réversible. La face porteuse du tapis se déplace audessus d'une table d'acier et béton agissant comme support. Le tapis lui‐même consiste en un squelette d'acier recourvert d'une couche de caoutchouc; la surface est recouverte d'un revêtement en fibres végétales qui permet un léger glissement en avant des sabots venant au contact dans des conditions comparables à celles d'une piste ordinaire. Le tapis peut être incliné de 10° dans le sens longitudinal et de 7°5 tranversalement. Pour diminuer le risque d'accident un système permet l'arrêt d'urgence.
Les chevaux se sont bien adaptés à l'exercice dans cet appareil même s'ils n'en avaient pas encore l'expérience. Une bonne corrélation fut observée entre la répétitivité des allures sur la piste et des allures sur le tapis. Un cheval étudié sur la piste et sur le tapis montra sur ce dernier des pas raccourcis. Cet appareil n'en n'est pas moins un très utile moyen d'étude de la locomotion équine.
Zusammenfassung
Eine Tretmühle zur Analyse der Fortbewegung des Pferdes wird beschrieben und ihr Potential für Forschung und klinische Untersuchungen besprochen. Die Tretmühle besteht aus einem Endlosband, das von einem hydraulischen Motor in verschiedenen Geschwindigkeiten bis zu 14 Meter pro Sekunde angetrieben wird. Die Richtung des Bandlaufes kann umgekehrt werden. Die Tragfläche des Bands läuft über einen Stahlbetontisch, der als flache Unterlage dient. Das Band selber besteht aus einer Stahlgrundlage, auf die eine Gummischicht geklebt wird. Bedeckt wird diese Konstruktion noch mit einer Matteschicht, die eine gewisse vorwärts rutschende Bewegung des laufenden Hufs erlaubt und damit die Bedingungen auf einer gewöhnlichen Rennbahn nachahmt. Das Band kann um 10° in transversaler Richtung verstellt werden. Um Verletzungsrisiken möglichst klein zu halten, wurde ein spezielles Nothalt‐System eingerichtet.
Die Pferde gewöhnten sich rasch an die Arbeit auf der Tretmühle, auch ohne vorhergehende Erfahrung. Es konnte eine gute Korrelation zwischen der “Gangrepetivität” auf der Bahn und derjenigen auf der Tretmühle gefunden werden. Ein Pferd zeigte auf der Tretmühle signifikant kürzere Schrittlängen als auf der Rennbahn, aber dieser Befund setzt den Wert der Tretmühle als nützliches Forschungsinstrument zur Untersuchung der Fortbewegung des Pferdes nicht herab.
This paper describes the major areas that require investigation in equine locomotion and outlines a plan for such research in both the Thoroughbred and Standardbred. Fifteen topics for future investigation have been selected and given an order of priority. These topics deal with characteristics of normal locomotion, factors which influence locomotion, the epidemiology and economics of lameness and the clinical identification of lameness.
Cet article étudie les domaines principaux de la locomotion équine oú une recherche est nécessaire. Un plan d'investigation est esquissé tant pour le pur sang que pour le trotteur. Quinze sujets propres à une recherche future sont sélectionnés et hiérarchisés par priorité. Ces topiques concernent la locomotion normale; les facteurs qui influencent la locomotion, l'épidémiologie, les conséquences économiques des boiteries, enfin l'identification clinique des boiteries.
Dieser Artikel beschreibt Gebiete, die eine weitere Erforschung der Fortbewegung des Pferdes bonötigen. Es wird ein Plan für derartige Forschungsarbeiten bei Vollblütern und amerikanischen Trabern vorgelegt. 15 Themen für eine zukünftige Bearbeitung wurden ausgewählt und in eine Prioritätsreinhenfolge eingestuft. Diese Themen umfassen Charakteristika der normalen Fortbewegung, Faktoren, die die Bewegungsabläufe beeinflussen, die Epidemiologie und wirtschaftliche Probleme von Lahmheiten und die klinische Erhebung von Lahmheit.
Locomotive disorders constitute a serious problem in horse racing which will only be rectified by a better understanding of the causative factors associated with disturbances of gait. This study describes a system for the quantitative analysis of the locomotion of horses at speed. The method is based on highspeed cinematography with a semi‐automatic system of analysis of the films. The recordings are made with a 16 mm high‐speed camera run at 500 frames per second (fps) and the films are analysed by special film‐reading equipment and a mini‐computer. The time and linear gait variables are presented in tabular form and the angles and trajectories of the joints and body segments are presented graphically.
Résumé
Les troubles locomoteurs créent de sérieuses difficultés chez le cheval de course; ces difficultés ne seront résolues qu'après avoir acquis une meilleure compréhension des facteurs provoquant une perturbation des allures.
On décrit dans cette étude un procédé pour l'analyse quantitative des mouvements des chevaux en pleine vitesse. La méthode est fondée sur la cinématographie à grande vitesse et l'analyse semi‐automatique des films. Les enregist‐rements sont faits à l'aide d'une caméra à grande vitesse de 16 mm, 500 vues par seconde. Les films sont analysés par un équipment spécial de lecture et un minicalculateur électronique. Le temps et les variables linéaires du mouvement sont présentés sous forme de tableaux, les angles et les trajectoires des articulations et des segments du corps sont représentés graphiquement.
Zusammenfassung
Eine gestörte Lokomotion stellt ein ernsthaftes Problem im Rennsport dar, das nur korrigiert werden kann durch ein besseres Verständnis der Ursachen, die mit Störungen der Gänge verbunden sind. Diese Studie beschreibt ein System für die quantitative Analyse der schnellen Fortbewegung des Pferdes. Die Methode beruht auf Hochgeschwindigkeitskine‐matographie gekoppelt mit einer halbautomatischen Film‐analyse. Die Aufnahmen sind mit einer 16 mm Hochgeschwin‐digkeitskamera (500 Bilder pro Sekunde) gemacht und die Filme dann analysiert mittels eines speziellen Ablesegerätes und mit einem Kleincomputer. Zeit und lineare Gangvariablen werden in Tabellenform dargeboten, die Winkel und der Weg von Gelenken und Körpersegmenten graphisch dargestellt.
This study was undertaken to establish limb loading patterns of sound horses at the trot, to provide a data base against which results for lame horses could be compared. Ground reaction force (GRF) data were collected from 20 clinically sound Dutch Warmblood horses. The data from at least 5 stance phases of each limb were averaged after standardisation to the animal's body mass and to the stance phase duration and resulted in 'representative' GRF data. The symmetry in the vertical GRF peak amplitudes, impulses and the stance phase duration comparing left and right limbs exceeded 97%. By averaging the 'representative' GRF of the 20 horses a 'standard' GRF pattern of the Dutch Warmblood horse at the trot was constructed. The GRF patterns at the trot, compared with those at the walk, showed only one vertical force peak in forelimbs and hindlimbs (11.59 N/kg and 10.21 N/kg, respectively). The retardatory and propulsory forces were distributed over the forelimbs and hindlimbs in such a way that the forelimbs contributed more to retardation (peak forces 1.13 and 0.79 N/kg), and the hindlimbs more to propulsion (-0.84 and -1.17 N/kg, respectively).
Highly-trained dressage horses were studied to test the hypothesis that stride length is altered independently of stride duration in the transitions between the collected, working, medium and extended trot. Six well-trained dressage horses were filmed at a frame rate of 150 frames/s performing the collected, working, medium and extended trots in a sand arena. Temporal, linear and angular data were extracted from the films, with 4 strides being analysed for each horse and gait type. There were no significant asymmetries between the left and rights limbs or diagonals when data from the whole group were pooled, but 3 horses showed asymmetries in one or more variables (P < 0.01). Analysis of variance and post-hoc tests indicated that the speed increased significantly (P < 0.01) from the collected (3.20 m/s) to the working (3.61 m/s) to the medium (4.47 m/s) to the extended (4.93 m/s) trot. The increases in speed were associated with a significant increase in stride length from 250 cm in the collected trot, to 273 cm in the working trot, 326 cm in the medium trot and 355 cm in the extended trot (P < 0.01). The lengthening of the stride was a result of increases between each gait type in the over-reach distance, whereas the diagonal distance was significantly longer in the extended than the collected trot only (P < 0.01). The stride duration tended to decrease as speed increased, and the difference became significant between the collected and extended trots (P < 0.01).
This study of the locomotion symmetry was undertaken to provide standard symmetry indices of a group of sound horses at the trot Using a 3D data collection system, the kinematics of the limb joints of 13 clinically nonlame horses were recorded while trotting in the standard conditions of the clinical lameness examination. A kinematic symmetry indice based on an inter-correlation method was defined and applied to the vertical displacement-time and joint angle-time diagrams of the left and right joints of the horses. For each horse, the mean symmetry indice of each joint was calculated using values from 5 trials. For each joint, these means were then averaged. To evaluate the repeatability of the locomotion symmetry, the intra- and inter-individual variabilities of the symmetry indices were studied.
The levels of symmetry of the markers of the trunk were generally lower than those of the limbs. Moreover, during the 5 trials these levels of symmetry were strongly variable but their mean values were very similar from one horse to another. In our experimental conditions the trunk presented a higher degree of freedom than the limbs. This high infra-individual variability indicated also that several trials are necessary to quantify the locomotion symmetry of a trotting horse.
In the same way, a lower level of symmetry of the hindlimbs, compared to the forelimbs, was proved by their lower values of symmetry indices. As opposed to the supporting role of the forelimbs, the propulsive role of the hindlimbs may explain this feature.
A high‐speed cinematographic analysis of interlimb time and linear gait characteristics was carried out at racing speed (12.0 m/sec; 1:23.6 min/km) in 30 clinically sound Standard‐bred trotters. In respect of the whole group of horses the racing trot was found to be a very regular and symmetric gait. The variation coefficient between different horses ranged from 8 to 21 per cent depending on the particular characteristic being investigated. The variations recorded in individual animals were about 60 per cent less than those found for the whole group. The most stable characteristics were the duration and length of the step. Some horses exhibited striking gait asymmetries and the possible causes are considered. It is also observed that some trotters adopt a transition type of gait that cannot be classified as a trot.
Résumé
L'analyse cinématographique à grande vitesse du temps écoulé entre les phases correspondantes de chaque membre et les caractères linéaires de l'allure a été faite sur 30 trotteurs Standarbreds cliniquement sains.
On constata que le trot était régulier et symétrique pour l'ensemble des animaux du groupe. Le coéfficient de variation entre les différents chevaux varia de 8 à 21% suivant le caractère retenu. Les variations observées chez un même individuel étaient d'environ 60% inférieures à celles observées au sein du groupe. La durée et la longueur de pas furent les caractères les plus stables.
Quelques animaux montrèrent nettement des allures asymètriques et l'on discute des causes possibles. Il fut remarqué chez quelques animaux une allure différente du trot.
Zusammenfassung
Eine Analyse von Hochgeschwindigkeitsfilmen—aufgenommen bei 30 klinisch gesunden Trabern in Renngesch‐windigkeit (12 m/sec; 1'23.6“/km)—bezog sich auf lineare Gangcharakteristika und die ”Zwischenbeinzeit„. Es wurde festgestellt, dass der Renntrab in dieser Pferdegruppe ein sehr regelmässiger und symmetrischer Gang ist. Der Variations‐koeffizient zwischen verschiedenen Pferden betrug 8 bis 21%, je nach dem untersuchten Merkmal. Die Schwankungen beim einzelnen Pferd erwiesen sich als etwa 60% geringer als die‐jenigen der ganzen Gruppe. Die stabilsten Merkmale waren Schrittdauer und –länge. Einige Pferde wiesen auffallende Gangasymmetrien auf, deren Ursachen diskutiert werden. Es konnte auch beobachtet werden, dass manche Traber einen Gangtyp annehmen, der nicht als Trab bezeichnet werden kann.
The movements of the individual limbs of 30 clinically sound Standardbred trotters were studied using high‐speed cinematography. At a speed of 12 metres per second (m/sec; 1:23.6 min/km) the mean stride length was 545 cm and the mean duration of the stride was 455 milliseconds (msecs). The stance phase in the forelimbs was 110 msecs and 117 msecs in the hindlimbs. This difference was due to a longer restraint period in the hindlimbs and resulted in slightly shorter swing phases for the hindlimbs.
The variations in any particular horse for stride length and for the duration of stride, stance, swing and propulsion were very small (variation coefficient: approximately 2 per cent). For the restraint stage, however, the variation coefficient was around 5 per cent. The variations noted between different horses were generally 2 to 3 times greater than those recorded for the same horse. There was a close correlation between stride and swing phase duration, suggesting that the swing phase was the main contributor to the stride‐time variations of different horses trotting at the same speed. The restraint and propulsion stages did not seem to play an important role in this respect for this group of animals.
Résumé
Les mouvements individuels des membres de 30 trotteurs Standardbred cliniquement sains ont étéétudiés à l'aide du cinématographe à grande vitesse. A la vitesse de 12 mètres seconde (soit 1m23 seconde 6/10 du kilomètre), la battue moyenne était de 545 cm et la durée moyenne de chaque battue était de 455 millisecondes. La phase d'appui des antérieurs durait 110 millisecondes, celle des postérieurs durait 117 millisecondes. Il en résultait une phase en suspension légérement plus brève pour les postérieurs.
Les variations pour chaque cheval en particulier, de la longueur et de la durée de la battue des phases à l'appui, en suspension de soutien, de propulsion, furent très faibles (variations d'environ 2%). Pour la phase de retenue, le coéfficient de variation était d'environ 5%. Les variations observées entre les différents chevaux étaient en général deux ou trois fois plus importants que celles constatées chez le même cheval.
On remarque une étroite corrélation entre la durée de la battue et celle de la phase suspension; cette corrélation parait indiquer que la phase en suspension est le principal facteur des variations des temps de battue de différents chevaux trottant à la même vitesse.
Les temps de retenue et de propulsion n'ont pas semblé jouer un rôle aussi important dans ces groupes d'animaux.
Zusammenfassung
Die Bewegung der einzelnen Gliedmassen von 30 klinisch gesunden Trabern wurde anhand von Hochgeschwindigkeits‐filmen untersucht. Bei einer Geschwindigkeit von 12 m/sec (1'23.6“/km) betrug die mittlere Schrittlänge 545 cm und die mittlere Schrittdauer 455 m/sec. Die Stützbeinphase betrug für die Vorderbeine 110 m/sec und für die Hinterbeine 117 m/sec. Der Unterschied ist die Folge eines verzögerten Abhebens der Hinterbeine, was eine etwas kürzere Hangbeinphase nach sich zeiht. Die Variationen beim einzelnen Pferd von Schrittlänge und –dauer, Stütz‐ und Hangbeinphase und Propulsion waren sehr klein (Variationskoeffizient ungefähr 2%). Der Variationskoeffizient für die Ruhephase belief sich auf 5%.
Die Variationen zwischen den Pferden waren zwei‐ bis dreimal grösser als beim einzelnen Tier. Zwischen Schrittdauer und Dauer der Hangbeinphase bestand eine enge Korrelation, was vermuten lässt, dass die Hangbeinphase am meisten beiträgt zu den Schrittdauer‐Schwankungen verscheidener Pferde, die mit der gleichen Geschwindigkeit traben. Ruhe‐ und Schubphasen scheinen in dieser Hinsicht keine entscheidende Rolle zu speilen.
Locomotive disorders constitute a serious problem in horse racing which will only be rectified by a better understanding of the causative factors associated with disturbances of gait. This study describes a system for the quantitative analysis of the locomotion of horses at speed. The method is based on highspeed cinematography with a semi‐automatic system of analysis of the films. The recordings are made with a 16 mm high‐speed camera run at 500 frames per second (fps) and the films are analysed by special film‐reading equipment and a mini‐computer. The time and linear gait variables are presented in tabular form and the angles and trajectories of the joints and body segments are presented graphically.
Résumé
Les troubles locomoteurs créent de sérieuses difficultés chez le cheval de course; ces difficultés ne seront résolues qu'après avoir acquis une meilleure compréhension des facteurs provoquant une perturbation des allures.
On décrit dans cette étude un procédé pour l'analyse quantitative des mouvements des chevaux en pleine vitesse. La méthode est fondée sur la cinématographie à grande vitesse et l'analyse semi‐automatique des films. Les enregist‐rements sont faits à l'aide d'une caméra à grande vitesse de 16 mm, 500 vues par seconde. Les films sont analysés par un équipment spécial de lecture et un minicalculateur électronique. Le temps et les variables linéaires du mouvement sont présentés sous forme de tableaux, les angles et les trajectoires des articulations et des segments du corps sont représentés graphiquement.
Zusammenfassung
Eine gestörte Lokomotion stellt ein ernsthaftes Problem im Rennsport dar, das nur korrigiert werden kann durch ein besseres Verständnis der Ursachen, die mit Störungen der Gänge verbunden sind. Diese Studie beschreibt ein System für die quantitative Analyse der schnellen Fortbewegung des Pferdes. Die Methode beruht auf Hochgeschwindigkeitskine‐matographie gekoppelt mit einer halbautomatischen Film‐analyse. Die Aufnahmen sind mit einer 16 mm Hochgeschwin‐digkeitskamera (500 Bilder pro Sekunde) gemacht und die Filme dann analysiert mittels eines speziellen Ablesegerätes und mit einem Kleincomputer. Zeit und lineare Gangvariablen werden in Tabellenform dargeboten, die Winkel und der Weg von Gelenken und Körpersegmenten graphisch dargestellt.