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Author (down) Hodson, E.F.; Clayton, H.M.; Lanovaz, J.L.
Title Temporal analysis of walk movements in the Grand Prix dressage test at the 1996 Olympic Games Type Journal Article
Year 1999 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.
Volume 62 Issue 2-3 Pages 89-97
Keywords Dressage; Horse; Kinematics; Locomotion; Gait
Abstract Video analysis was used to measure temporal characteristics of the collected walk, extended walk and half pirouette at walk of eleven competitors during the team dressage competition at the 1996 Summer Olympic Games in Atlanta, GA. Forelimb stance durations, hind limb stance durations, lateral step intervals and diagonal step intervals were symmetrical for the right and left sides in the collected and extended walk strides, but there were left-right asymmetries in the forelimb stance duration and in the lateral step interval in the half pirouette strides. For both collected and extended walk strides, hind limb stance duration was significantly longer than forelimb stance duration. The mean values for the group of eleven horses showed that the collected and extended walks had a regular rhythm. The half pirouette strides showed an irregularity in which there was a short interval between footfalls of the outside forelimb and inside hind limb, and along interval between footfalls of the inside hind limb and inside forelimb. This irregularity reflected an early placement of the inside hind limb. The stance times of both hind limbs were prolonged and this finding, in combination with the early placement of the inside hind limb, led to an increase in the period of tripedal support in each stride of the half pirouette. This was interpreted as a means of maintaining the horses' balance in the absence of forward movement.
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Call Number refbase @ user @ Serial 3960
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Author (down) Heleski, C.R.; McGreevy, P.D.; Kaiser, L.J.; Lavagnino, M.; Tans, E.; Bello, N.; Clayton, H.M.
Title Effects on behaviour and rein tension on horses ridden with or without martingales and rein inserts Type Journal Article
Year 2009 Publication The Veterinary Journal Abbreviated Journal
Volume 181 Issue 1 Pages 56-62
Keywords Horse behaviour; Horse welfare; Equitation science; Rein tension; Martingales
Abstract Unsteady hand position can cause discomfort to the horse, potentially leading to conflict behaviours (CB) such as head tossing or tail lashing. Some instructors feel that martingales or elastic rein inserts can reduce discomfort caused by inexperienced and unsteady hands. Others consider these devices to be inappropriate [`]crutches'. Four horses and nine riders were tested under three conditions in random order: plain reins, adjustable training martingales (TM), and elasticised rein inserts (RI). Rein-tension data (7 s) and behavioural data (30 s) were collected in each direction. Rein-tension data were collected via strain-gauge transducers. Behavioural data were assessed using an ethogram of defined behaviours. No differences in the number of CB were observed. Mean rein tension for TM was higher than that of RI or controls. Relative to the withers, the head was lower for horses ridden with martingales. Carefully fitted martingales may have a place in riding schools that teach novices.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1090-0233 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 4807
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Author (down) Geutjens, C.A.; Clayton, H.M.; Kaiser, L.J.
Title Forces and pressures beneath the saddle during mounting from the ground and from a raised mounting platform Type Journal Article
Year 2008 Publication The Veterinary Journal Abbreviated Journal
Volume 175 Issue 3 Pages 332-337
Keywords Electronic saddle mat; Total force; Peak pressure; Equestrian; Kinetics
Abstract The objective was to use an electronic pressure mat to measure and compare forces and pressures of the saddle on a horse's back when riders mounted from the ground and with the aid of a mounting platform. Ten riders mounted a horse three times each from the ground and from a 35 cm high mounting platform in random order. Total force (summation of forces over all 256 sensors) was measured and compared at specific points on the force-time curve. Total force was usually highest as the rider's right leg was swinging upwards and was correlated with rider mass. When normalized to rider mass, total force and peak pressure were significantly higher when mounting from the ground than from a raised platform (P < 0.05). The area of highest pressure was on the right side of the withers in 97% of mounting efforts, confirming the importance of the withers in stabilizing the saddle during mounting.
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Notes Approved no
Call Number Admin @ knut @ Serial 4344
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Author (down) Dutto, D.J.; Hoyt, D.F.; Clayton, H.M.; Cogger, E.A.; Wickler, S.J.
Title Moments and power generated by the horse (Equus caballus) hind limb during jumping Type Journal Article
Year 2004 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol
Volume 207 Issue Pt 4 Pages 667-674
Keywords Animals; Biomechanics; Hindlimb/*physiology; Horses/*physiology; Locomotion/*physiology
Abstract The ability to jump over an obstacle depends upon the generation of work across the joints of the propelling limb(s). The total work generated by one hind limb of a horse and the contribution to the total work by four joints of the hind limb were determined for a jump. It was hypothesized that the hip and ankle joints would have extensor moments performing positive work, while the knee would have a flexor moment and perform negative work during the jump. Ground reaction forces and sagittal plane kinematics were simultaneously recorded during each jumping trial. Joint moment, power and work were determined for the metatarsophalangeal (MP), tarsal (ankle), tibiofemoral (knee) and coxofemoral (hip) joints. The hip, knee and ankle all flexed and then extended and the MP extended and then flexed during ground contact. Consistent with our hypothesis, large extensor moments were observed at the hip and ankle joints and large flexor moments at the knee and MP joints throughout ground contact of the hind limb. Peak moments tended to occur earlier in stance in the proximal joints but peak power generation of the hind limb joints occurred at similar times except for the MP joint, with the hip and ankle peaking first followed by the MP joint. During the first portion of ground contact (approximately 40%), the net result of the joint powers was the absorption of power. During the remainder of the contact period, the hind limb generated power. This pattern of power absorption followed by power generation paralleled the power profiles of the hip, ankle and MP joints. The total work performed by one hind limb was 0.71 J kg(-1). Surprisingly, the knee produced 85% of the work (0.60 J kg(-1)) done by the hind limb, and the positive work performed by the knee occurred during the first 40% of the take-off. There is little net work generated by the other three joints over the entire take-off. Velocity of the tuber coxae (a landmark on the pelvis of the animal) was negative (downward) during the first 40% of stance, which perhaps reflects the negative work performed to decrease the potential energy during the first 40% of contact. During the final 60% of contact, the hip, ankle and MP joints generate positive work, which is reflected in the increase of the animal's potential energy.
Address Department of Kinesiology and Health Promotion, California State Polytechnic University, Pomona, CA 91768, USA. ddutto@csupomona.edu
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-0949 ISBN Medium
Area Expedition Conference
Notes PMID:14718509 Approved no
Call Number Equine Behaviour @ team @ Serial 3654
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Author (down) de Oliveira, K.; Soutello, R.V.G.; da Fonseca, R.; Costa, C.; de L. Meirelles, P.R.; Fachiolli, D.F.; Clayton, H.M.
Title Gymnastic Training and Dynamic Mobilization Exercises Improve Stride Quality and Increase Epaxial Muscle Size in Therapy Horses Type Journal Article
Year 2015 Publication Journal of Equine Veterinary Science Abbreviated Journal
Volume 35 Issue 11 Pages 888-893
Keywords Equine; Hippotherapy; Therapeutic exercise; Dynamic mobilization exercise; Physical training; Three-dimensional movement
Abstract The objective was to evaluate the efficacy of gymnastic training (GYM) and dynamic mobilization exercises (DMEs) on stride length (SL) and epaxial muscle size in therapy horses. Nine cross-bred hippotherapy horses that performed three, 25-minute therapeutic riding sessions per week throughout the study period were randomly assigned to three experimental groups: a control group in which the horses were sedentary with no additional physical activity; a group that performed DMEs; and a group that performed both DMEs and additional GYM including pelvic tilting, backing, turning in small circles, and walking over a raised rail to strengthen the abdominal and pelvic stabilizer muscles. The exercises were performed 3 days per week for 3 months, with evaluations at the start and end of the study. Stride quality was assessed by measuring SL and tracking distance (TD). Epaxial muscle size was monitored by ultrasonographic measurement of m. longissimus dorsi (LD) thickness and m. multifidi (MM) cross-sectional area. Paired t tests were used to compare within groups across time, and between groups were detected using analysis of variance with Tukey post hoc test. When walking at 1.3 m/s, SL and TD at walk increased significantly (P < .05) in horses subjected to GYM. Thickness of LD did not change in any group, but cross-sectional area of MM increased significantly by 3.55 cm2 (DME) and 3.78 cm2 (GYM). It was concluded that GYM training improved stride quality and DME-stimulated MM hypertrophy which has been shown to improve intervertebral joint stability in other species.
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ISSN 0737-0806 ISBN Medium
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 6593
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Author (down) Clayton, H.M.; Larson, B.; Kaiser, L.A.J.; Lavagnino, M.
Title Length and elasticity of side reins affect rein tension at trot Type Journal Article
Year 2011 Publication The Veterinary Journal Abbreviated Journal
Volume 188 Issue 3 Pages 291-294
Keywords Horse; Equitation; Training; Rein aids
Abstract This study investigated the horse’s contribution to tension in the reins. The experimental hypotheses were that tension in side reins (1) increases biphasically in each trot stride, (2) changes inversely with rein length, and (3) changes with elasticity of the reins. Eight riding horses trotted in hand at consistent speed in a straight line wearing a bit and bridle and three types of side reins (inelastic, stiff elastic, compliant elastic) were evaluated in random order at long, neutral, and short lengths. Strain gauge transducers (240 Hz) measured minimal, maximal and mean rein tension, rate of loading and impulse. The effects of rein type and length were evaluated using ANOVA with Bonferroni post hoc tests. Rein tension oscillated in a regular pattern with a peak during each diagonal stance phase. Within each rein type, minimal, maximal and mean tensions were higher with shorter reins. At neutral or short lengths, minimal tension increased and maximal tension decreased with elasticity of the reins. Short, inelastic reins had the highest maximal tension and rate of loading. Since the tension variables respond differently to rein elasticity at different lengths, it is recommended that a set of variables representing different aspects of rein tension should be reported.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1090-0233 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 6124
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Author (down) Clayton, H.M.; Lanovaz, J.L.; Schamhardt, H.C.; van Wessum, R.
Title The effects of a rider's mass on ground reaction forces and fetlock kinematics at the trot Type Journal Article
Year 1999 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume 30 Issue Pages 218-221
Keywords Animals; Body Weight; Computer Simulation; Gait/*physiology; Horses/*physiology; Physical Conditioning, Animal/*physiology; Stress, Mechanical; Weight-Bearing/*physiology
Abstract Ground reaction force (GRF) measurements are often normalised to body mass to facilitate inter-individual comparisons. The objective of this study was to explore the effect of a rider on the GRFs and fetlock joint kinematics of trotting horses. The subjects were 5 dressage-trained horses and 3 experienced dressage riders. Ground reaction force measurements and sagittal view videotapes were recorded as the horses trotted at the same velocity in hand (3.49 +/- 0.52 m/s) and with a rider (3.49 +/- 0.46 m/s). Data were time-normalised to stance duration. Ground reaction force measurements were expressed in absolute terms and normalised to the system mass (horse or horse plus rider). All the horses showed changes in the same direction when comparing the ridden condition with the in-hand condition. There was an increase in the absolute peak vertical GRFs of the fore- and hindlimbs with a rider. However, the mass-normalised peak vertical GRFs were lower for the ridden condition, with the peak occurring later in the forelimbs and earlier in the hindlimbs compared with the inhand condition. Maximal fetlock angle and its time of occurrence were similar for the 2 conditions, but the fore fetlock joint was more extended during the later part of the stance phase in ridden horses. The presence of a rider appeared to affect the GRFs and fetlock joint kinematics differently in the fore- and hindlimbs, and the ridden horse did not seem to be equivalent to a proportionately larger horse. This should be considered when normalising for body mass in studies comparing horses in hand and ridden horses.
Address Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824-1314, USA
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Notes PMID:10659255 Approved no
Call Number Equine Behaviour @ team @ Serial 3733
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Author (down) Clayton, H.M.; Hampson, A.; Fraser, P.; White, A.; Egenvall, A.
Title Comparison of rider stability in a flapless saddle versus a conventional saddle Type Journal Article
Year 2018 Publication Plos One Abbreviated Journal Plos One
Volume 13 Issue 6 Pages e0196960
Keywords
Abstract The purpose of a saddle is to improve the rider's safety, security, and comfort, while distributing the forces exerted by the rider and saddle over a large area of the horse's back without focal pressure points. This study investigates the effects on rider stability of an innovative saddle design that differs from a conventional saddle in having no flaps. Five horses were ridden by their regular rider in their usual saddle and in a flapless saddle. A pressure mat (60 Hz) placed between the saddle and the horse's back was used to determine the position of the center of pressure, which represents the centroid of pressure distribution on the horse's back. Data were recorded as five horses were ridden at collected and extended walk, trot and canter in a straight line. Data strings were split into strides with 5 strides analysed per horse/gait/type. For each stride the path of the rider's center of pressure was plotted, maximal and minimal values in the anteroposterior and mediolateral directions were extracted, and ranges of motion in anteroposterior and mediolateral directions were calculated. Differences between the conventional and flapless saddles were analysed using mixed models ANOVA. Speed and stride length of each gait did not differ between saddles. Compared with the conventional saddle, the flapless saddle was associated with significant reductions in range of motion of the rider's center of pressure in the mediolateral direction in all gaits and in the anteroposterior direction in collected trot, extended trot and extended canter. The improved stability was thought to result from the absence of saddle flaps allowing the rider's thighs to lie in more adducted positions, which facilitated the action of the lumbopelvic-hip musculature in stabilizing and controlling translations and rotations of the pelvis and trunk. The closer contact between rider and horse may also have augmented the transfer of haptic information.
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Publisher Public Library of Science Place of Publication Editor
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 6423
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Author (down) Clayton, H.M.
Title Classification of collected trot, passage and piaffe based on temporal variables Type Journal Article
Year 1997 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl
Volume Issue 23 Pages 54-57
Keywords Analysis of Variance; Animals; Discriminant Analysis; Gait/*physiology; Hindlimb/physiology; Horses/*physiology; Locomotion/*physiology; Male; Running/physiology; Time Factors; Videotape Recording; Walking/physiology
Abstract The objective was to determine whether collected trot, passage and piaffe could be distinguished as separate gaits on the basis of temporal variables. Sagittal plane, 60 Hz videotapes of 10 finalists in the dressage competitions at the 1992 Olympic Games were analysed to measure the temporal variables in absolute terms and as percentages of stride duration. Classification was based on analysis of variance, a graphical method and discriminant analysis. Stride duration was sufficient to distinguish collected trot from passage and piaffe in all horses. The analysis of variance showed that the mean values of most variables differed significantly between passage and piaffe. When hindlimb stance percentage was plotted against diagonal advanced placement percentage, some overlap was found between all 3 movements indicating that individual horses could not be classified reliably in this manner. Using hindlimb stance percentage and diagonal advanced placement percentage as input in a discriminant analysis, 80% of the cases were classified correctly, but at least one horse was misclassified in each movement. When the absolute, rather than percentage, values of the 2 variables were used as input in the discriminant analysis, 90% of the cases were correctly classified and the only misclassifications were between passage and piaffe. However, the 2 horses in which piaffe was misclassified as passage were the gold and silver medallists. In general, higher placed horses tended toward longer diagonal advanced placements, especially in collected trot and passage, and shorter hindlimb stance percentages in passage and piaffe.
Address Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
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Language English Summary Language Original Title
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Notes PMID:9354290 Approved no
Call Number Equine Behaviour @ team @ Serial 3738
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Author (down) Clayton, H.M.
Title Comparison of the stride kinematics of the collected, medium, and extended walks in horses Type Journal Article
Year 1995 Publication American Journal of Veterinary Research Abbreviated Journal Am J Vet Res
Volume 56 Issue 7 Pages 849-852
Keywords Analysis of Variance; Animals; *Gait; Horses/*physiology; *Locomotion; Motion Pictures; Physical Conditioning, Animal; Walking
Abstract Six horses, highly trained for dressage competition, were used to study the stride kinematics of the walk, and to compare the kinematics of the collected, medium, and extended walks. Horses were filmed in a sagittal plane at a rate of 150 frames/s; temporal, linear, and angular data were extracted from the films. Results of ANOVA and Duncan's multiple range test indicated that the speed of the collected walk (1.37 m/s) was significantly (P < 0.01) slower than that of the medium (1.73 m/s) and extended (1.82 m/s) walks, values for which were not significantly different from each other. The increase in speed was associated with a significant increase in stride length, from 157 cm in the collected walk to 193 cm in the extended walk. This was a result of an increase in the over-tracking distance, whereas there was no significant difference in the distance between lateral placements of the limbs. Stride duration decreased (P < 0.01) from the collected walk (1,159 ms) to the extended walk (1,064 ms). Angles of the metacarpal and metatarsal segments, measured on the palmar/ plantar aspect, were higher at impact and lower at lift off in the collected than in the extended walk (P < 0.01). This indicated greater range of angular motion of this segment during the stance phase in the extended walk. Only 1 of the 6 horses had a regular 4-beat rhythm of the footfalls, with equal time elapsing between the lateral and diagonal footfalls.
Address Department of Veterinary Anatomy, Western College of Veterinary Medicine, Canada
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-9645 ISBN Medium
Area Expedition Conference
Notes PMID:7574149 Approved no
Call Number Equine Behaviour @ team @ Serial 3743
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