Trotting Horses refers to a specific gait in equines characterized by a two-beat diagonal stride, where the legs move in pairs diagonally across the horse's body. This gait is commonly observed in various horse breeds and is a fundamental aspect of disciplines such as harness racing and dressage. Trotting is often evaluated for its rhythm, balance, and speed, particularly in competitive settings. This topic encompasses a range of research studies and scholarly articles that investigate the biomechanics, training techniques, and performance metrics associated with trotting in horses. Additionally, the page includes research on the physiological and anatomical adaptations that enable this specific gait, as well as its implications for equine health and athletic performance.
Hoyt DF, Wickler SJ, Biewener AA, Cogger EA, De La Paz KL.The activity of muscles can be concentric (shortening), eccentric (lengthening) or isometric (constant length). When studying muscle function it is important to know what the muscle fascicles are actually doing because the performance of muscle is strongly influenced by the type of activity: force decreases as a function of shortening velocity during concentric contractions; force produced during eccentric contractions can be stronger than maximum isometric force, and force production is enhanced if a concentric contraction follows an eccentric phase. It is well known that length changes of mu...
Stoiber B, Zach C, Izay B, Windberger U.In situations where capillary perfusion in skeletal muscles is limited, changes in blood flow play an important role. Especially alterations in intrinsic erythrocyte factors like red cell aggregation and deformability would increase blood flow resistance. In our study we investigated whether whole blood and plasma viscosity influence exercise tolerance during submaximal training and whether a difference can be realized between trained and untrained standardbred trotters. Venous blood from 42 healthy adult trotters (20 horses at the beginning of their training and 22 well trained horses) was in...
Licka T, Kapaun M, Peham C.Equine lameness is commonly evaluated when the horse is being ridden, but the influence of the rider on the lameness has not been documented. Objective: To document the effect of 2 riders of different training levels on the vertical movement of the head and croup. Methods: Twenty mature horses were ridden at trot by an experienced dressage rider and a novice rider, as well as trotted in hand. Kinematic measurements of markers placed on the horse's head and sacral bone were carried out. The asymmetries of the vertical head and sacral bone motion were calculated as lameness parameters and compar...
Biknevicius AR, Mullineaux DR, Clayton HM.Gaited horses employ 4-beat stepping (singlefoot) gaits that extend into speeds typical of trots. Ground reaction force (GRF) patterns of these specialised gaits have not been reported; therefore, appraisal of these gaits using nongaited horse kinetics may lead to clinical misjudgements. Objective: GRFs of tölting Icelandic horses will be comparable in profile and magnitude with those of trotting horses. Methods: Forelimb and hindlimb GRFs were obtained for 10 Icelandic horses ridden at a tölt. These data were evaluated across 3 speed ranges: <2, 2.5-5 and >5 m/sec. Results: Virtually all ve...
Gustås P, Johnston C, Roepstorff L, Drevemo S, Lanshammar H.The transmission of shockwaves following hoof impact is proposed to be one major source of stress to the limb. In the forelimb, there are indications that the period of horizontal deceleration of the hoof is related to the attenuation of shockwaves. In the hindlimb, information about the hoof deceleration has been lacking. Objective: To compare hoof deceleration patterns between the fore- and hindlimbs. Methods: Seven Standardbreds were trotted by hand over a force plate covered with sand, with triaxial accelerometers mounted on the fore and hind hooves. Variables representative of deceleratio...
Clayton HM, Sha D, Stick JA, Mullineaux DR.Descriptions of 3D kinematics assist in understanding joint function and dysfunction, and are an essential step toward 3D inverse dynamic analysis. Objective: To measure 3D carpal joint motion during trotting. Methods: Three-dimensional trajectories of bone-fixed markers on the radius and third metacarpus of the right forelimb of 3 healthy horses were recorded at 120 Hz using a 6-camera analysis system. Joint kinematics were calculated in terms of helical angles between the 2 segments using a spatial attitude method. Results: All horses showed carpal extension and internal rotation of the meta...
van Heel MC, Barneveld A, van Weeren PR, Back W.Studies on hoof balance have, so far, only assessed the effects of strong and relatively unrealistic interventions due to technical limitations of measuring equipment. For the assessment of more subtle interventions, other techniques are necessary. Objective: To test a sensitive pressure measurement system during locomotion and to set a standard for further studies by using the system to evaluate the effects of trimming. Methods: Eighteen horses were measured before and after trimming with an interval of 4 weeks. Trimming was standardised to a straight hoof-pastern axis. The horses trotted ove...
Human movement scienceDecember 14, 2004
Volume 23, Issue 5 663-671 doi: 10.1016/j.humov.2004.10.006
Peham C, Licka T, Schobesberger H, Meschan E.The aim of this study was to show that the motion pattern of a well-ridden horse varies less than the motion pattern of an unridden horse. In order to do so, we recorded the motion of two markers, one attached to the dorsal spinous processus of lumbar vertebra L4, the other to the right fore hoof. In total, we measured 21 horses in trot, ridden and unridden, with a fitting and with a non-fitting saddle. After breaking down the entire time series of the three-dimensional motion of the markers into their respective motion cycles, we computed a measure of motion pattern variability for the motion...
Weishaupt MA, Wiestner T, Hogg HP, Jordan P, Auer JA.The objective of this study was to establish representative treadmill ground reaction force (GRF) and interlimb co-ordination time data of clinically sound horses at the trot. It was anticipated that these normative standards would provide a reference data base against which lame horses could be compared. GRF-time histories were collected from 30 Warmblood riding horses with easy, wide natural gaits. Data were recorded of all four limbs simultaneously by the use of an instrumented treadmill. A total of 912 stride cycles per limb were analysed for force, time and spatial parameters and were ave...
Landman MA, de Blaauw JA, van Weeren PR, Hofland LJ.A population of 805 horses (70 per cent dressage, 20 per cent show jumpers and 10 per cent trotters) with orthopaedic problems was examined for signs of lameness and back problems, irrespective of their original complaints. In the horses with a back problem the prevalence of lameness was 74 per cent, and back problems were diagnosed in 32 per cent of the lame horses. These percentages were significantly higher than those recorded in a control population of 399 horses, of which 20 per cent were lame and 12 per cent had back problems. In the group of horses with orthopaedic problems there was a ...
Dutto DJ, Hoyt DF, Cogger EA, Wickler SJ.Although the forces required to support the body mass are not elevated when moving up an incline, kinematic studies, in vivo tendon and bone studies and kinetic studies suggest there is a shift in forces from the fore- to the hindlimbs in quadrupeds. However, there are no whole-animal kinetic measurements of incline locomotion. Based on previous related research, we hypothesized that there would be a shift in forces to the hindlimb. The present study measured the force produced by the fore- and hindlimbs of horses while trotting over a range of speeds (2.5 to 5 m s(-1)) on both level and up an...
Leleu C, Bariller F, Cotrel C, Barrey E.Locomotion analysis is increasingly used to assess the gait of horses in the selection and training of equine athletes. We have developed a specific locomotor test for fast trotting harnessed horses that uses an accelerometric device. We describe here the reproducibility of the locomotor test and the validation of its use to analyse trotters on the racetrack. We measured the performance of eight horses under the same conditions three times in a single week. We then tested the influence of five tracks on the variables measured using eight different trotters every two days. The horses trotted at...
Eliashar E, McGuigan MP, Wilson AM.Collapsed heels conformation has been implicated as causing radical biomechanical alterations, predisposing horses to navicular disease. However, the correlation between hoof conformation and the forces exerted on the navicular bone has not been documented. Objective: The angle of the distal phalanx in relation to the ground is correlated to the degree of heel collapse and foot conformation is correlated to the compressive force exerted by the deep digital flexor tendon on the navicular bone. Methods: Thirty-one shod Irish Draught-cross type horses in routine work and farriery care were trotte...
Kramer J, Keegan KG, Kelmer G, Wilson DA.To evaluate pelvic movement over a large number of strides in sound horses and in horses with induced hind limb lameness by applying methods to the pelvis that have been described for evaluating vertical head movement in horses with induced forelimb lameness. Methods: 17 adult horses. Methods: Horses were filmed while trotting on a treadmill before and after induction of transient mild and moderate hind limb lamenesses. Vertical pelvic movement was measured by a signal decomposition method. The vertical pelvic signal was decomposed into a periodic component (A1) that occurred at half the strid...
Keegan KG, Yonezawa Y, Pai PF, Wilson DA, Kramer J.To compare a sensor-based accelerometer-gyroscopic (A-G) system with a video-based motion analysis system (VMAS) technique for detection and quantification of lameness in horses. Methods: 8 adult horses. Methods: 2 horses were evaluated once, 2 had navicular disease and were evaluated before and after nerve blocks, and 4 had 2 levels of shoe-induced lameness, alternatively, in each of 4 limbs. Horses were instrumented with an accelerometer transducer on the head and pelvis, a gyroscopic transducer on the right forelimb and hind feet, and a receiver-transmitter. Signals from the A-G system were...
Chateau H, Degueurce C, Denoix JM.To develop a method that allows quantification of the 3 anatomic rotations in the digital joints of moving horses and measure these rotations when horses are walking in a straight line on a hard track. Methods: 4 healthy French Trotter horses. Methods: Triads of ultrasonic kinematic markers were surgically linked to the 4 distal segments of the digits of the left forelimb of each horse. Three-dimensional (3-D) coordinates of these markers were recorded in horses walking in a straight line. The three angles of rotation of each digital joint were calculated by use of a joint coordinate system as...
Licka TF, Peham C, Frey A.To use electromyography (EMG) to measure physiologic activity of the longissimus dorsi muscles of horses during trotting on a treadmill. Methods: 15 adult horses (5 to 20 years old that weighed 450 to 700 kg) that did not have clinical signs of back pain. Methods: Data were recorded for each horse during trotting on a treadmill at speeds of 2.6 to 4.4 m/s. Surface electromyography was recorded bilaterally from the longissimus dorsi muscles at the levels of T12, T16, and L3. Results: In each motion cycle, 2 EMG maxima were found at the end of the diagonal stance phases. The EMG activity peaked ...
Khumsap S, Lanovaz JL, Rosenstein DS, Byron C, Clayton HM.To study the effect of unilateral synovitis in the distal intertarsal and tarsometatarsal joints on locomotion, including the compensating effects within and between limbs. Methods: 4 clinically normal horses. Methods: Gait analyses including kinematics, force plate, and inverse dynamic analysis were performed at the trot before lameness, after which synovitis was induced by injecting endotoxin into the right distal intertarsal and tarsometatarsal joints. Gait analyses were repeated 24 to 30 hours later during lameness. Differences between the stride variables during the 2 conditions (lame and...
Fazio F, Ferrantelli V, Piccione G, Caola G.In the athletic horse, the efficiency of physical exercise during activity is strictly
connected to several organic–functional characteristics. Among these, cardiovascular
function takes a primary role in determining the quality of performance. The morphological and functional changes occurring in the cardiovascular system during physical
exercise are due to the increasing demand required to deal with intense muscular
activity. Thus, the cardiovascular physiological response to physical exercise is characterized both by transitory modifications and adjustments that are similar in both
t...
Vigre H, Chriél M, Hesselholt M, Falk-Rønne J, Kjaer Ersbøll A.A follow-up study focusing on health problems interfering with optimal training of Danish Standardbred trotters was conducted with the participation of seven professional trainers. Our aim was to estimate the incidence of health problems that cause interruptions of optimal training, and to identify associations between the hazard of lameness and selected risk factors. The study population was dynamic and contained data of 265 Standardbred trotters monitored during 5 months in 1997 and 1998. The horses were >or=2 years old. Optimal training was defined as when the horse followed scheduled tr...
Robert C, Valette JP, Pourcelot P, Audigié F, Denoix JM.A thorough knowledge of the horse's back and limb movements at different speeds is important in the design of training programmes and the prevention of speed-related injuries. The objective of this study was to investigate changes in muscle activity and kinematics of the trot with increased speed. To evaluate these effects, 4 Saddlehorses were recorded while trotting on a horizontal treadmill at speeds ranging from 3.5-6.0 m/s. The 3-D trajectories of skin markers on the left side of the horse and the dorsal midline of the trunk were established. Electrical activity was obtained simultaneously...
Nielsen BD, O'Connor CI, Rosenstein DS, Schott HC, Clayton HM.The use of weight-training to alter bone strength has not been investigated in horses. Recognising that bone responds to loading, we studied the effect of carrying weight on bone development during training. Seventeen horses were divided into 3 groups: controls exercised counterclockwise in a free-flow exerciser; the weight group performed the same exercise carrying progressively increasing weight up to 45 kg and the weight supplement group also received a myo-anabolic supplement. Radiographic equivalence measure of bone mineral content of zones of the third metacarpi (MCIII) was determined on...
Wickler SJ, Hoyt DF, Cogger EA, McGuire R.We hypothesised that trotters during an extended trot have lower energetic costs of locomotion (CT) than horses not bred for this behaviour. VO2 was measured as a function of speed in 7 Arabian horses (3 trained to extend their trotting speeds) and in 2 horses, of similar mass, bred to trot (Hackney). Both oxygen consumption and CT increased with speed and there was, contrary to our hypothesis, no difference between breeds. In Arabians at 6.5 m/s, CT had increased 25% above the CT at 5.0 m/s (normal transition speed). For Hackneys at 6.8 m/s, the CT was almost 35% higher. Stride frequencies in...
Roepstorff L, Johnston C, Drevemo S, Gustås P.According to riding texts, draw reins are supposed to support increased collection. This has not been measured objectively. Therefore, the objective of this study was to determine whether a horse ridden with draw reins would relatively increase weightbearing of the hindquarters while worked with the draw reins compared to a normal rein. Ground reaction forces were measured in 8 horses at the slow trot over a force plate in 3 different experimental set-ups: 1) riding with only a draw rein (DR); 2) riding with the combination of a normal and a draw rein (NR-DR) and 3) riding with a normal rein (...
Hoyt DF, Molinari M, Wickler SJ, Cogger EA.The objective was to understand how the stance-phase kinematics of the hindlimb of trotting horses change with speed under 3 conditions (level, loaded and incline), to compare our results with the predictions of the spring-mass model and to help focus our future studies of muscle function. Video recordings were made of 5 Arabian horses trotting on a treadmill. Five consecutive strides were digitised and averaged for each trial. The angle-time diagrams were qualitatively similar to those reported previously. As speed increases, the range of motion of the hindlimb increases, as predicted by the ...
Clayton HM, Hoyt DF, Wickler SJ, Cogger EA, Lanovaz JL.Net joint powers and energies have been described in walking horses during the swing phase of the stride in the fore- and hindlimb (Clayton et al. 2001). During trotting, swing phase net joint powers have been described in the forelimb but not in the hindlimb. The effects of velocity on power profiles and energy patterns are important in relation to locomotor energetics. The objective of this study was to evaluate velocity-dependent changes in hindlimb net energy profiles of the swing phase during trotting. Inverse dynamic analysis was used to calculate net joint energies at the hindlimb joint...
Johnston C, Holmt K, Faber M, Erichsen C, Eksell P, Drevemo S.The relationship between structure and function is important in the judgement of the horse. Twenty sound riding horses walked and trotted on a treadmill. The movement of the backs of each of the horses was measured using a commercially available movement analysis system. Morphometric, spatiotemporal and kinematic information were correlated to investigate the effect of conformation on movement. Taller and heavier horses seem to have longer thoracic and lumbar backs, and are wider at the pelvis. Horses with longer strides extended and flexed their backs in the caudal saddle region to a greater ...
Leleu C, Gloria E, Renault G, Barrey E.The aim of this study was to describe the correlation between the phases of the limb cycle of trotters on the track and specific points on the acceleration curves obtained from a new gait analysis system. We compared kinematic data obtained by video image analysis and 3-dimensional acceleration recordings made on 3 French trotters in training. They trotted on a race track at speeds of 8.33, 10 and 11.66 m/s, with a final stretch at maximum speed. Their locomotion was recorded with a synchronised video camera at a frame frequency of 200 Hz and with the Equimétrix gait analysis system. The gait...
Lanovaz JL, Khumsap S, Clayton HM, Stick JA, Brown J.The tarsal joint is a common site of injury for many sport horses. Understanding the biomechanics of this complex joint begins with developing a clear picture of the kinematics during normal locomotion. This study describes the 3D kinematics of the tarsal joint by measuring the motion of the tibia and third metatarsus in 4 sound Quarter Horses with targets attached directly to the bones via steel pins. The objective was to determine if the tarsus had significant motion outside the tarsocrural joint. Two Steinmann pins were inserted into the lateral side of the right hindlimb and marker triads ...
Morgan K, Funkquist P, Nyman G.The aim of this study was to study the physiological, especially thermoregulatory, responses during intense exercise in the clipped horse compared to the horse with winter coat. Six Standardbred trotters were studied before and after clipping. They performed an inclined incremental high intensity treadmill exercise test and were monitored during recovery. The clipped horse differed significantly (ANOVA) during exercise as compare to coated: less increase in central venous blood temperature, higher skin surface temperature, greater difference skin to ambient temperature and higher rate of nonev...
Pourcelot P, Audigié F, Degueurce C, Denoix JM, Geiger D.This study was conducted to evaluate a method for quantifying the flexion-extension movements of the back of horses trotting on a track in the conditions of the clinical lameness examination. Using a 3-D kinematic analysis system, the successive positions of four markers placed at regular intervals between the withers and the tuber sacrale were recorded. To isolate the flexion-extension movements of the back, the positions of these four markers were recomputed in a trunk-related co-ordinate system of the horse. Then, for each frame, the equation of the third-order polynomial that best fitted t...
Couroucé-Malblanc A, Leleu C, Bouchilloux M, Geffroy O.Developmental orthopaedic lesions are commonly found in French Standardbred horses. One of the main questions asked by trainers, owners and veterinarians is what impact these lesions have on the racing career and racing performances of horses. Objective: To study the prevalence and distribution of developmental orthopaedic lesions in young French Standardbred trotters and to relate them to racing performance. Methods: Feet, fetlock, tarsus and stifle regions were radiographed in 865 two-year-old French Standardbred trotters. Abnormal radiographic findings (ARF) were evaluated for 12 anatomical...
Waldern NM, Wiestner T, Ramseier LC, Weishaupt MA.To compare gait mechanics and limb loading in Icelandic horses tölting and trotting at equal speeds and estimate their impact on orthopedic health. Methods: 12 orthopedically normal Icelandic horses. PROCEDURES Kinetic and kinematic gait variables were simultaneously recorded as each horse was ridden at a tölt and trot on an instrumented treadmill at 3.4 m/s and 3.9 m/s. Differences between gaits were tested via 1-factor repeated-measures ANOVA. Results: Horses had a higher stride rate and lower stride impulses at a tölt than at a trot. For forelimbs at a tölt, shorter relative stance dura...
Nauwelaerts S, Aerts P, Clayton H.Gaits can be defined based upon specific interlimb coordination patterns characteristic of a limited range of speeds, with one or more defining variables changing discontinuously at a transition. With changing speed, horses perform a repertoire of gaits (walk, trot, canter and gallop), with transitions between them. Knowledge of the series of kinematic events necessary to realize a gait is essential for understanding the proximate mechanisms as well as the control underlying gait transitions. We studied the kinematics of the actual transition from trot to canter in miniature horses. The kinema...
Peloso JG, Stick JA, Soutas-Little RW, Caron JC, DeCamp CE, Leach DH.Motion of 6 clinically sound horses trotting at a speed of 4 m/s on a treadmill was captured by video cameras before and 9, 16, and 23 days after amphotericin-induced lameness to determine the quantitative variables of three-dimensional computer-assisted image analysis that objectively describe carpal lameness. Amphotericin-B was used to induce lameness, and phenylbutazone (2.2 mg/kg of body weight, PO, once) and butorphanol tartrate (0.1 mg/kg IM, q 6 h, to effect) were used to control discomfort. Four 60-Hz cameras were symmetrically placed around the treadmill to capture 6 seconds of images...
Kobluk CN, Schnurr D, Horney FD, Sumner-Smith G, Willoughby RA, Dekleer V, Hearn TC.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 prese...
Starke SD, May SA.The evaluation of hindlimb lameness remains a major challenge in everyday clinical practice. In the absence of clear guidelines, veterinarians use different visual assessment methods for this task whose robustness is unknown. Objective: Determination of the robustness of five visual hindlimb lameness assessment methods based on the comparison of left and right tuber coxae movement. Methods: Validated mathematical hindlimb lameness model based on experimental data from the literature. Methods: Vertical movement of left (LTC) and right (RTC) tuber coxae was simulated for the range of common hind...
Peham C, Licka T, Mayr A, Scheidl M, Girtler D.Treadmills are widely used in equine motion analysis. For the evaluation of the trot of a horse, a trotting speed with low variation between motion cycles is necessary to make the measurements reproducible. The aim of this study is to show how an individual 'optimum' trotting speed for lameness quantification can be determined. In this study, the stability of a horse's gait pattern was evaluated by calculating the standard deviation (S.D.) of motion-cycle speed (MCS). In trot, eighteen horses were analysed at several speeds. The measurements were taken with the ExpertVision System (Motion Anal...
Hagen J, Geburek F, Kathrinaki V, Naem MA, Roecken M, Hoffmann J.This study aimed to examine how short-term loss of proprioception in the equine foot influences the individual COP path during the stance phase of the trot in sound horses. Ten horses were evaluated to be objectively non-lame using the 'Equinosis Q System and subsequently examined using a portable pressure measuring system with pressure foils fixed directly underneath both front hooves prior to and after perineural anesthesia of the palmar digital nerves. The individual COP paths of both forelimbs was assessed prior to and after unilateral and bilateral abaxial sesamoid nerve blocks. COP from ...
Egenvall A, Byström A, Pökelmann M, Connysson M, Kienapfel-Henseleit K, Karlsteen M, McGreevy P, Hartmann E.Horseracing is under public scrutiny with increasing demands to safeguard horse welfare. It is accepted that, as a result of bit pressure and/or equipment, mouth lesions accompany many types of horse use, including racing. However, there are currently no data available on the range of bit pressures in driven trotters. Our aim was to investigate whether rein tension (RT, proxy for bit pressures) differs among gaits, between tempo within gait, between horses and drivers, and between left/right reins. Standardbreds (n = 9), driven by experienced drivers (n = 11), performed exercise tests on a rac...
Lindahl C, Bergman Bruhn Å, Andersson IM.The Swedish equine sector is considered a high-risk work environment, with relatively high injury rates and high severity of injuries. General safety research has identified a correlation between the safety performance and safety culture, but little is known about the intricacies of the safety culture in the Swedish equine sector, especially concerning managers' and employees' perceptions of their work environment. The safety climate assessment is recognised as an effective tool for identifying potential problems in the workplace, thus enhancing safety behaviour and decreasing the frequency an...
St George L, Spoormakers TJP, Roy SH, Hobbs SJ, Clayton HM, Richards J, Serra Bragança FM.The reliability of surface electromyography (sEMG) has not been adequately demonstrated in the equine literature and is an essential consideration as a methodology for application in clinical gait analysis. This observational study investigated within-session, intra-subject (stride-to-stride) and inter-subject reliability, and between-session reliability of normalised sEMG activity profiles, from triceps brachii (triceps), latissimus dorsi (latissimus), longissimus dorsi (longissimus), biceps femoris (biceps), superficial gluteal (gluteal) and semitendinosus muscles in n = 8 clinically non-lam...
Thoresen SI, Jenkins A, Ask E.Chromosomal DNA fingerprinting indicated that Norwegian Taylorella equigenitalis strains are genetically homogeneous and similar to some Swedish isolates but different from other European strains. As contagious equine metritis is rarely a serious disease in Norwegian horses, we conclude that the dominant T. equigenitalis strain in Norway is a genetically homogeneous clone of low virulence.
Mottini V, Leleu C, Cotrel C.It has become apparent through analysis of elite races over the past 20 years that mounted races are always slower than harnessed races when performed by the same horses over the same distances on the same tracks. Objective: To investigate and compare physiological and gait variables in mounted and harnessed activities in trotters. Methods: Ten trotters were taken at random in 2 standardised field exercise tests one week apart: a harnessed and a mounted test with standardised weight jockeys and drivers. Speed, heart rate (HR), respiratory frequency (RF), blood lactate concentration (La), strid...
Clayton HM, Lavagnino M, Kaiser LJ, Stubbs NC.To compare effects of 4 types of stimulation devices attached to the hind feet on hoof flight, joint angles, and net joint powers of trotting horses. Methods: 8 clinically normal horses. Methods: Horses were evaluated under 5 conditions in random order: no stimulators, loose straps (10 g), lightweight tactile stimulators (55 g), limb weights (700 g), and limb weights with tactile stimulators (700 g). Reflective markers on the hind limbs were tracked during the swing phase of 6 trotting trials performed at consistent speed to determine peak hoof heights and flexion angles of the hip, stifle, ta...
Linford RL.Quantitated locomotion analysis is increasingly being used during assessment and treatment of gait disorders in human beings. Locomotion analysis is also thought to have potential for enhancing the assessment of lameness in horses. Availability of high-speed video recording systems has simplified the process of quantitated locomotion analysis; however, the high cost of such systems has limited their use for routine clinical assessment in horses. The temporal resolution of 500- to 1,000-images/s (Hz) recording systems is beyond what has been considered necessary for precise quantitation of shor...
Jansen WL, van der Kuilen J, Geelen SN, Beynen AC.The hypothesis tested was that the intake of extra fat at the expense of an isoenergetic amount of nonstructural carbohydrates reduces fibre utilisation in horses. In a crossover trial with feeding periods of 42 days each, 6 mature trotting horses (age 4-12 years, bodyweight 340-476 kg) were given either a control or test diet. The test concentrate was formulated to contain 37% of net energy in the form of soybean oil. The control concentrate contained an isoenergetic amount of corn starch plus glucose. The concentrates were fed in combination with the same amount of hay so that the control an...
Valera M, Galisteo AM, Molina A, Miró F, Gómez MD, Cano MR, Agüera E.The purpose of this study was to estimate the genetic parameters of biokinematic variables in Spanish Purebred (SPB) horses in order to select those of sufficient interest to be measured in the pre-selection of the animals for possible inclusion in the breeding programme. Kinematic analysis of 130 SPB horses 4.6+/-1.5 years old were recorded at the trot (4m/s) on a treadmill. Genetic parameters were estimated using VCE software and a bivariate mixed animal model including age and stud as fixed effects and animal additive genetic effect and residual error as random effects. In general, heritabi...
Olsen HF, Meuwissen T, Klemetsdal G.The aim of this study was to examine how to apply optimal contribution selection (OCS) in the Norwegian and the North-Swedish cold-blooded trotter and give practical recommendations for the future. OCS was implemented using the software Gencont with overlapping generations and selected a few, but young sires, as these turn over the generations faster and thus is less related to the mare candidates. In addition, a number of Swedish sires were selected as they were less related to the selection candidates. We concluded that implementing OCS is feasible to select sires (there is no selection on m...
Nauwelaerts S, Clayton HM.Estimates of the position of the centres of mass (CM) of body segments are usually extrapolated relative to bony landmarks as determined in cadaver studies. This extrapolation assumes that segments are rigid bodies. Since the trunk represents a large percentage of the total body mass in horses, violation of the rigid body assumption by the trunk segment has important consequences for studying the biomechanics of equine locomotion. Objective: To assess the magnitude of error in CM position due to deformability of the trunk segment and the timing of these errors during the trotting stride. The h...
Brard S, Ricard A.An A/C mutation responsible for the ability to pace in horses was recently discovered in the gene. It has also been proven that allele C has a negative effect on trotters' performances. However, in French trotters (FT), the frequency of allele A is only 77% due to an unexpected positive effect of allele C in late-career FT performances. Here we set out to ascertain whether the genotype at SNP (linked to ) should be used to compute EBV for FT. We used the genotypes of 630 horses, with 41,711 SNP retained. The pedigree comprised 5,699 horses. Qualification status (trotters need to complete a 2,0...
Velie BD, Smith PM, Fjordbakk CT, Solé M, Jäderkvist Fegraeus K, Rosengren MK, Røed KH, Ihler CF, Lindgren G, Strand E.Dynamic laryngeal collapse (DLC) associated with poll flexion is the most common disorder of the upper respiratory tract (URT) in the Norwegian-Swedish Coldblooded Trotter (NSCT). The disorder, which has also been diagnosed in other breeds of trotters and gaited horses, appears to be related to anatomic phenotypes and only occurs during poll flexion when the horse is exercised 'on the bit'. Objective: Identify genomic regions associated with DLC in the NSCT by combining a rigorous phenotyping protocol with genomic data from a high-density equine genotyping array. Methods: Prospective case/cont...
Räsänen LA, Myllymäki T, Hyyppä S, Maisi P, Pösö AR.Plasma concentrations of hypoxanthine, uric acid, and allantoin, which are breakdown products of adenine nucleotides, were measured in Standardbred and Finnhorse trotters during and after an exercise test on a high-speed treadmill, after an incremental exercise test performed on a racetrack, and after a racing competition. Fiber-type composition of the middle gluteal muscle and the muscle concentrations of adenine nucleotides and inosine monophosphate were measured after the racetrack test. Changes in the concentration of hypoxanthine were not observed in any of the tests. Peak concentration o...
Barr AR, Dow SM, Goodship AE.Recordings of forelimb ground reaction forces were made from 48 normal ponies moving at the trot, to evaluate the relationships between bodyweight, vertical ground reaction forces, the timing of individual events within the stance phase and the total contact time. There were highly significant correlations between the mean vertical ground reaction forces and bodyweight. The mean vertical ground reaction forces, corrected for bodyweight, were inversely correlated with the total contact time suggesting that higher trotting speeds may be associated with greater vertical ground reaction forces. Th...
Heinonen E, Nyman G, Meriläinen P, Högman M.Dependent atelectatic lung areas open towards the end of inspiration when the lung opening pressure increases, and recollapse during expiration. We hypothesized that inhaled nitric oxide (NO) counteracts hypoxic vasoconstriction in these collapsing lung areas, resulting in increased pulmonary shunt perfusion. Methods: We administered NO as a pulse and varied the pulse timing during inspiration in equine anaesthesia, where atelectasis develops regularly. Six spontaneously breathing standard breed trotters were studied under isoflurane anaesthesia in lateral recumbency. NO pulsed into the first ...