bluuebunny/crossref_metadata_2025_split huggingface dataset:
Jumping characteristics of naïve foals: lead changes and description of temporal and linear parameters
Authors: SANTAMARÍA S. , BACK W. , van WEEREN P. R. , KNAAP J. , BARNEVELD A. 
Published: June 2010

SummaryThe selection of foals as future showjumpers remains a subjective process based on qualitative parameters; and hence, frequently suffers from disparity in the criteria used by experts in the field. A detailed biomechanical description of foals while jumping would be most helpful in providing a better basis for the accurate assessment of their future athletic ability. The Qualisys Pro Reflex system was used to capture 3‐dimensional kinematics of 41 Dutch Warmblood foals age 6 months free jumping a vertical fence, preceded by a cross pole fence. The left lead was the most preferred lead for both the fore‐ and hindlimbs, from the landing following the cross poles to the first move‐off stride after clearing the vertical fence. The foals displayed a high incidence of rotary gallop during both the jump stride (divided into take‐off, jump suspension and landing) and the first move‐off stride, while change of lead was frequently observed during jump suspension. At the take‐off side of the fence, the trailing forelimb in the last approach stride was placed furthest from the fence, whereas the trailing hindlimb at take‐off was placed closest (P<0.05). At the landing side, the trailing forelimb was the closest and the leading hindlimb of the move‐off stride 1 was the furthest (P<0.05). The trailing forelimb in the approach stride 1 had a significantly longer stance phase duration than the leading forelimb. At landing, the leading forelimb stance phase lasted longer than that of the trailing forelimb (P<0.05). The hindlimbs did not differ in their stance phase duration at take‐off. The height reached by the hooves above the fence top was significantly greater in the hind limbs (P<0.05). In addition, the hindlimbs (97.1 ± 2.6%) shortened more than the forelimbs (92.6 ± 5.7%) (P<0.05). It is concluded that the overall jumping technique of foals is similar to that reported in literature for mature horses. If the patterns are consistent throughout the rearing period, the quantitative analysis of the kinematics of free jumping foals may provide a valid quantitative basis for early selection.
Early evaluation of dressage ability in different breeds
Authors: BARREY E. , DESLIENS F. , POIREL D. , BIAU S. , LEMAIRE S. , RIVERO J.‐L. L. , LANGLOIS B. 
Published: June 2010

SummaryDressage is one of the Olympic equestrian sports practiced in several countries using different horse breeds. Specific characteristics of the walk, trot and canter are required for dressage. It has been assumed that some of these traits could be selected for genetically and contribute to dressage performance. The purpose of this study was to compare the walk, trot and conformation characteristics in young horses of different breeds used for dressage. A total of 142 horses age 3 years were classified into 3 groups of breeds (German, French and Spanish saddle horses) and tested using the same procedure. The skeletal conformation measurements were made by image analysis. Gait variables of the walk and trot were measured by the accelerometric gait analysis system Equimetrix. Discriminant analysis could explain the variability between the groups by taking into account the walk (P<0.0003), trot (P<0.0001) and conformation variables (P<0.0001). Many gait and conformation variables were significantly different between the breeds. In summary, the German horses had gait characteristics more adapted for dressage competition, and the results of this group could be used as a reference for early evaluation in dressage. Purebred Spanish horses could be considered as a reference for collected gaits used for farm work and old academic dressage. The gait and conformation tests could be applied in a breeding or crossing plan to detect more accurately young horses with good dressage ability.
Effect of trotting speed, load and incline on hindlimb stance‐phase kinematics
Authors: HOYT D. F. , MOLINARI M. , WICKLER S. J. , COGGER E. A. 
Published: June 2010

SummaryThe 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 spring‐mass model. This is the result of increased range of motion in the coxofemoral and tarsal joints. The hindlimb does not ‘land short ‐ take off long’. When trotting up an incline, the hindlimb undergoes a greater range of motion because of increased retraction resulting from increased extension of the coxofemoral joint. At hoof contact on an incline, the 3 proximal joints are more flexed than on the level. Carrying a load had no effect on kinematics. These results suggest that there may be larger changes in strain with speed in muscles acting at the coxofemoral and tarsal joints than at the femorotibial joint, and that locomotion up an incline will change muscle strain more than carrying a load.
Analysis of trotter gait on the track by accelerometry and image analysis
Authors: LELEU C. , GLORIA E. , RENAULT G. , BARREY E. 
Published: June 2010

SummaryThe 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 variables were calculated using 3‐dimension acceleration data recorded at the sternum (dorso‐ventral, longitudinal and lateral axes) at a sampling rate of 100 Hz.Three phases of the stride were clearly identified on the dorsoventral acceleration signal: hoof‐landing, midstance phase and toe‐off. Braking and propulsion phases were identified on the corresponding longitudinal acceleration signal. The weight‐bearing diagonal was identified by observing the lateral signal. The stride temporal variables (stride, stance, braking and propulsion durations for both diagonals), measured by video analysis and by acceleration signal analysis, were not significantly different (P>0.05). The identification of specific points on the acceleration pattern allowed an accurate temporal analysis of the stride. Potential applications could be the determination of locomotor factors related to racing performance or assessment of locomotor disorders at high speed.
Biomechanical implications of uphill training on the aetiology of tendinitis
Authors: TAKAHASHI T. , KAI M. , HADA T. , ETO D. , MUKA K. , ISHIDA N. 
Published: June 2010

SummaryIt has been reported that a small decrease in the strain in the superficial digital flexor tendon (SDFT) occurs if the toe is raised during walking. Although walking on a slope appears similar to raising the toe, it is unclear whether uphill exercise decreases the strain in the SDFT. Because the force or strain on tendons is one of the important factors leading to tendon stress injury, we hypothesised that reducing the force in the SDFT during exercise may prevent tendinitis. The purpose of this study was to determine the effects of treadmill inclination on the force in the SDFT in the walking horse. ‘Arthroscopically implantable force probes’ (AIFP) were implanted into the SDFT of the forelimb of 4 horses. The AIFP output was recorded during walking on a treadmill inclined at 0%, 3%, 8% and then 0% again. When the inclination increased from 0 to 8%, the first peak of force in the SDFT decreased significantly, the second increased significantly, but the maximal force and the area under the force‐time curve did not change. In conclusion, uphill walking on an inclined treadmill did not decrease the maximal force in the SDFT or the area under the force‐time curve, however, the patterns of force were altered.Future research should focus on the force distributions of tendons and ligaments at faster gaits, because the effects of a change in hoof angle and slope may be greater at faster gaits.
Movements of thoracic and abdominal compartments during ventilation at rest and during exercise
Authors: MARLIN D. J. , SCHROTER R. C. , CASHMAN P. M. M. , DEATON C. M. , POOLE D. C. , KINDIG C. A. , McDONOUGH P. , ERICKSON H. H. 
Published: June 2010

SummaryThe present investigation utilised simultaneous measurements of chest (Ch) and abdominal (Ab) circumferences and respiratory airflow to test the hypothesis that Ch circumferential expansion contributes proportionally little to tidal volume in the running Thoroughbred. During exercise, there were only small changes in Ch and Ab circumference and no increase with increasing tidal volume. At rest, walk and trot, the flow, Ch and Ab signals were in phase. However, during canter and gallop, the Ch and Ab changes were 180° out of phase with each other and both were out of phase with airflow. In contrast to exercise, increase in ventilation at rest achieved by administration of lobeline resulted in a 4–6‐fold increase in tidal volume; large excursions of the chest were always in phase with airflow. Furthermore, 3 horses showed an increase in chest circumference, demonstrating that chest stiffness per se does not preclude chest circumferential expansion. In conclusion, in the absence of significant increases in either Ch or Ab expansion during running, elongation of the thoracoabdominal segment may be the main determinant of tidal volume.
Dynamic upper airway changes and arterial blood gas parameters during treadmill exercise
Authors: DURANDO M. M. , MARTIN B. B. , HAMMER E. J. , LANGSAM S. P. , BIRKS E. K. 
Published: June 2010

SummaryThe primary goal was to investigate the relationship between dynamic upper airway abnormalities and arterial blood gas tensions during exercise. Horses that completed a high‐speed treadmill examination consisting of upper‐airway videoendoscopy, blood gas evaluation and electrocardiogams and, postexercise, echocardiograms and tracheal washes, were included. An age‐matched group of fit, healthy Thoroughbreds, trained to run on a high‐speed treadmill, served as controls for blood gas values at specific exercise speeds.One hundred and nineteen horses completed the treadmill examination. Sixty (50%) were Thoroughbreds (TB), 51 (43%) Standardbreds (STD) and 8 (7%) other breeds. Mean ± s.d. age TB 3.8 ± 2.2 years and STD 4.0 ± 1.7 years, with no gender predilection. Fifty‐four horses (45%) had abnormal upper respiratory tract (URT) abnormalities alone or in combination with abnormalities in another body system. Thirty‐eight (70%) were TB, 14 (26%) were STD and 2 (4%) were other breeds. Of these, 24 (45%) had exercising Pao2 values significantly lower than those observed in healthy TB. Nineteen (35%) horses also had significantly elevated exercising PaCo2. Only 14 (12%) horses had abnormal clinical findings in the URT alone, and of these, only 3 (21%) had an abnormally low Pao2 and/or elevated Paco2. Multiple URT abnormalities were more commonly associated with abnormal exercising blood gases than were single disorders, but pharyngeal collapse (PC) was much more commonly associated with abnormal values if only one disorder was detected. Fifty‐five percent (n = 65) of all cases admitted had no evidence of URT disease. Twenty‐two (35%) were TB and 37 (57%) were STD. Twenty (31%) of these had abnormally low Pao2 and 14 (22%) had elevated PaCo2 values. Seventy percent (14) of the horses with abnormal Pao2 were STD, while almost 80% (11) of the horses with elevated Paco2 were STD.These data suggest that dynamic URT dysfunction can adversely affect gas exchange during exercise. While multiple abnormalities were more commonly associated with gas exchange problems than were single disorders, pharyngeal collapse, either alone or in combination with other URT problems, was the disorder most frequently associated with blood gas abnormalities. Additionally, URT disease was more commonly seen in TB, and the proportion of URT diagnoses in horses with abnormal blood gases reflected this percentage, while STD without URT disease had a much higher incidence of abnormal blood gases than did TB without URT abnormalities.
Evidence of an association between inflammatory airway disease and EIPH in young Thoroughbreds during training
Authors: NEWTON J. R. , WOOD J. L. N. 
Published: June 2010

SummaryIn an epidemiological study of risk factors for exercise‐induced pulmonary haemorrhage (EIPH) in young Thoroughbreds in the UK, in which 148 horses contributed 1614 horse‐months of data, there were 64 (4%) episodes of endoscopically visible tracheal bleeding and 824 (51%) episodes of increased quantities of haemosiderophages in tracheal washes. There were increases in prevalence and risk of EIPH by both definitions with age from < 2‐> 4 years, season of sampling from winter (Nov‐Jan) to autumn (Aug‐Oct) and several different measures of airway inflammation, including tracheal mucus, neutrophil proportion, inflammation score and fungal material in tracheal washes. There was considerable variability in the prevalence of EIPH between trainers. EIPH in the preceding month significantly increased the risk of the condition the following month. There was no evidence that EIPH was associated with infection of the airways with even large numbers ofStreptococcus zooepidemicusorPasteurella‐like spp., which are significantly associated with airway inflammation in younger racehorses. Multiple logistic regression modelling that took account of random variability between horses and the effects of each trainer and an episode the preceding month, confirmed that after controlling for the other risk factors, EIPH was still significantly associated with increasing age, different seasons, airway inflammation and evidence of airway fungal material.
Hyperhydration prior to moderate‐intensity exercise causes arterial hypoxaemia
Authors: LEON L. SOSA , HODGSON D. R. , EVANS D. L. , RAY S. P. , CARLSON G. P. , ROSE R. J. 
Published: June 2010

SummaryThe second day of a 3‐day event is the most physically demanding of the 3 days. If this is performed under hot and humid environmental conditions, detrimental effects on cardiovascular and thermoregulatory function and, therefore, on exercise capacity, may occur due to exercise‐induced dehydration. We hypothesised that the administration of fluid equivalent to 6% of the horse's bodyweight prior to a simulated second day of a 3‐day event would increase plasma volume and limit increases in core temperature. Seven Standardbred geldings underwent a training protocol prior to the study. A standardised exercise test was developed for each horse so that exercise intensity at each phase would be the same percentage of the maximal heart rate for all horses. The exercise test involved 4 phases: Phase A involved 30 min exercise at 3.7 m/s (∼25% V̇O2max); Phase B 4 min exercise at 8 m/s (∼60% V̇O2max); and Phase C 50 min at 3.7 m/s, after which there was a 10 min rest. Phase D involved 14 min at 7.3 m/s (55% V̇O2max). In a cross‐over design, horses were grouped randomly and allocated to either exercise with no fluid (control) or ∼26 I isotonic fluid by nasogastric tube, 120 min prior to exercise. Arterial and mixed venous blood samples were collected prior to exercise, towards the end of each of the phases and during the rest period. The administration of fluid prior to exercise resulted in a pre‐exercise bodyweight gain of 21.3 ± 1.2 kg. Hyperhydration resulted in a greater degree of arterial hypoxaemia than the control group in Phases B and D, but not in Phases A and C or at rest. During Phases B and D, mean PaO2 values in the horses that received fluid were about 15 torr lower than in the control group, but there were no differences in PaCO2 values between the 2 groups. In both arterial and mixed venous blood, pH and HCO3‐ were significantly lower in the group that were hyperhydrated. We concluded that the most likely cause of the more severe arterial hypoxaemia in the hyperhydrated group during the intense exercise phase was some degree of pulmonary oedema, from the extravasation of the administered fluid.Hyperhydration prior to exercise may be detrimental to respiratory function and therefore care must be taken in administration of large volumes of fluid prior to exercise.
The effect of a tongue‐tie in horses with dorsal displacement of the soft palate
Authors: FRANKLIN S. H. , NAYLOR J. R. J. , LANE J. G. 
Published: June 2010

SummaryTongue‐ties are frequently used in an attempt to prevent dorsal displacement of the soft palate (DDSP). The aim of this study was to determine the efficacy of a tongue‐tie in horses clinically affected with the disorder. Videoendoscopic recordings and measurements of respiratory airflow were made simultaneously during high intensity treadmill exercise in 6 Thoroughbred racehorses with confirmed DDSP, with and without a tonguetie. DDSP was confirmed in all 6 horses without the tongue‐tie but occurred in only 4 horses with the tongue‐tie in place. In one horse the palate displaced only on slowing down after intense exercise and in the other horse DDSP did not occur although palatal instability remained. The presence of the tongue‐tie did not result in any significant alteration in run‐time to fatigue or in any of the respiratory variables measured. The results suggest that the use of a tongue‐tie may prevent DDSP in individual horses although it is not effective in the majority, consistent with the widely accepted anecdotal reports of success rates for its use. Where DDSP was not prevented, application of a tongue‐tie did not improve ventilation.
Exercise‐induced pulmonary perfusion redistribution in heaves
Authors: HARMEGNIES N. F. , DUVIVIER D. H. , VANDENPUT S. N. , ART T. , LEKEUX P. M. , VOTION D. M. 
Published: June 2010

SummaryThis study aimed to compare exercise‐induced pulmonary perfusion redistribution in healthy vs. ‘heavey’ horses using scintigraphy, a minimally invasive technique. Six healthy (A) and 5 ‘heavey’ horses in remission (BI) and during clinical signs of disease (BII) were investigated. Dimensions of the exercising pulmonary perfusion (QE) images were expressed in percent of the resting perfusion (QR) images. Computed QEto QRratios (QE/QR) images enabled the definition of the region more perfused at exercise than at rest (R1).In all groups, exercise induced a major enlargement of the Q image but a larger increase of the lung height was found in ‘heavey’ horses. Compared to A, ‘heavey’ horses showed a larger R1region with a significantly higher QE/QR. Location of R1pointed out the dorsal lung region as a major site of pulmonary perfusion redistribution for all groups.This work demonstrated (1) the feasibility of using scintigraphy for studying exercise‐induced pulmonary perfusion redistribution; (2) perfusion redistribution to the dorsal lung with exercise and (3) an intensified redistribution in ‘heavey’ horses, either clinically affected or not.
Thermoregulatory‐induced compromise of muscle blood flow in ponies during intense exercise in the heat: a contributor to the onset of fatigue?
Authors: McCONAGHY F. F. , HODGSON D. R. , HALES J. R. S. , ROSE R. J. 
Published: June 2010

SummaryCardiac output (Q) and tissue blood flows (BF) were measured in four ponies at rest, after 30 min of moderate exercise (ME) (∼30% V̇O2max) and following moderately intense exercise (M‐IE) (∼65%) until fatigue, in a mildly hot (MH) environment (dry bulb temperature = 41°C, wet bulb temperature = 27.5°C). Exercise at both intensities resulted in increases in Q (15.6 ± 1.7 [rest] vs. 35.8 ± 2.6 [ME] vs. 48.6 ± 3.9 [M‐IE] l/min) and V̇O2(4.7 ± 0.9 vs. 24.5 ± 1.2 vs. 55.8 ± 5.8 ml/kg/min). When compared to ME, M‐IE resulted in decreases in BF to the skin (∼15%), nonworking muscle (46%), fat (93%), gut (56%), kidneys (57%), CNS (31–66%) and an increase in BF to respiratory (68%), limb (98.5%) and cardiac (50%) muscles. In contrast, BF to working muscle during ME in thermoneutral (TN) conditions (McConaghyet al.2002) was higher than found during ME in MH. We calculated that limb BF was ∼25% lower for ME in MH vs. ME in TN. Similarly, we estimated that limb BF during M‐IE in MH was ∼25% lower than for M‐IE in TN. Attenuation of the increases in muscle BF during exercise in the heat may be a determinant of the onset of fatigue.
Effects of somatotropin and training on indices of exercise capacity in Standardbreds
Authors: GERARD M. P. , HODGSON D. R. , LAMBETH R. R. , RAY S. P. , ROSE R. J. 
Published: June 2010

SummaryThe recent availability of recombinant equine somatotropin (eST) has led to concern about its use as an ergogenic aid in racehorses. This study was undertaken to investigate the changes in exercise capacity in maturing horses in a training programme, and to assess whether eST is an ergogenic aid to this group. We tested the hypothesis that the combination of training and eST, compared to training alone, would further improve exercise capacity in maturing Standardbreds, by virtue of ST's anabolic effects and potential to enhance cardiac function, circulating fluid volume and red cell mass. Twelve, untrained Standardbreds (mean ± s.d. 20.7 ± 1.1 months) were paired according to similar bodyweight and then assigned randomly to treatment or control group. The horses underwent a 12 week treadmill training programme. Methionyl eST (10 μg/kg for the first 7 days, then 20 μg/kg) was administered once daily, i.m., for 42 consecutive days (Weeks 4 to 9 inclusive) to 6 horses in the treatment group. All horses performed a standardised maximal exercise test to fatigue at Weeks 0, 3, 6, 9, and 12. During each exercise test V̇O2, Vco2, plasma lactate concentrations ([La]), heart rates, blood volume and total run time were measured.There was no significant effect of eST administration on V̇O2max, V200, VLA4, LA9, red cell volume (RCV), plasma volume (PV), or run time to fatigue. Combining the data for all horses, training significantly altered the V̇O2max(mean ± s.d. 98.2 ± 11.1 ml/kg/min in Week 0 to 117.6 ± 4.8 ml/kg/min in Week 12), VLA4(5.1 ± 0.8 m/s to 7.4 ± 1.0 m/s), LA9(12.7 ± 3.9 mmol/l to 7.1 ± 1.9 mmol/l), RCV (46.3 ± 4.7 ml/kg to 63.5 ± 5.0 ml/kg), PV (46.0 ± 4.8 ml/kg to 57.0 ± 6.3 ml/kg), and run time to fatigue (431.8 ± 30.9 to 490.2 ± 30.5 s), but not V200(5.0 ± 0.5 m/s to 5.2 ± 1.1 m/s). The administration of eST to young Standardbred horses in training did not significantly improve their exercise capacity or indices of fitness. However, these maturing horses demonstrated a rapid physiological response to training exercise. Further research is required to determine the relationship between exercise capacity and ST in the horse.