Article

Evaluation of Indicators of Weight-Carrying Ability of Light Riding Horses

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

To answer the question of whether horse height, cannon bone circumference, and loin width can be used as indicators of weight-carrying ability in light horses, eight mature horses underwent a submaximal mounted standard exercise test under four conditions: carrying 15, 20, 25, or 30% of their body weight. Heart rate was monitored, plasma lactate concentration was determined in jugular blood samples pre-exercise, immediately post-exercise, and 10 minutes post-exercise, with serum creatine kinase activity determined at the same times as plasma lactate concentrations, with additional samples collected at 24 hours and 48 hours post-exercise. Muscle soreness and muscle tightness scores were determined using a subjective scoring system 24 hours before and 24 hours after exercise. Heart rates remained significantly higher when the horses carried 25 and 30% of their body weight. Plasma lactate concentrations immediately and 10 minutes after exercise differed when horses carried 30% of their body weight compared with 15, 20, and 25% weight carriage. Horses tended to have a greater change in muscle soreness and muscle tightness when carrying 25% of their body weight, and a significant change in soreness and tightness scores was found in horses carrying 30% of their body weight. Loin width and cannon bone circumference were found to be negatively correlated to the changes in muscle soreness and tightness scores. In conclusion, the data suggest that horses with wider loin and thicker cannon bone circumference became less sore when carrying heavier weight loads.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... A significant increase in plasma creatine kinase activity was noted when the rider:horse bodyweight ratio was changed from 25% to 30%. Similarly, heart rates, breathing frequencies, and plasma lactate concentration increased with increasing weight ratio; however, only when starting from a level of 20% rider:horse bodyweight ratio [26]. When the rider:horse bodyweight ratio was increased from 15.3% to 17.2% and then 18.5% by adding weights, no short-term alterations in heart rate, behavior, and gait symmetry were observed [27]. ...
... The assessment of the correct weight of riders for their horse is a multifactorial issue with many inter-related aspects [8]. Therefore, it is not surprising that conventional thermal image features did not elucidate the effect of rider:horse bodyweight ratio, which was in an acceptable range of 10-20% and the horse's thoracolumbar region was not overloaded >20% [26,30]. Our results do not contradict the literature that states that overload (rider:horse bodyweight ratio 21.3%) may be reflected by an increase in heart rate and superficial body temperature of the horse's neck and trunk [24], as we did not include this higher rider:horse bodyweight ratio group. ...
... Moreover, only the SumEntrp and Entropy for the red component in ROI 1, differed between all three bodyweight ratio groups, 11.2%, 14.2%, and 16.9%. These entropy-related features have been suggested to reflect the increased degree of thermal energy dissipation [25,31,40], indicating a high heterogeneity of texture [26,60]. ...
Full-text available
Article
Appropriate matching of rider–horse sizes is becoming an increasingly important issue of riding horses’ care, as the human population becomes heavier. Recently, infrared thermography (IRT) was considered to be effective in differing the effect of 10.6% and 21.3% of the rider:horse bodyweight ratio, but not 10.1% and 15.3%. As IRT images contain many pixels reflecting the complexity of the body’s surface, the pixel relations were assessed by image texture analysis using histogram statistics (HS), gray-level run-length matrix (GLRLM), and gray level co-occurrence matrix (GLCM) approaches. The study aimed to determine differences in texture features of thermal images under the impact of 10–12%, >12 ≤15%, >15 <18% rider:horse bodyweight ratios, respectively. Twelve horses were ridden by each of six riders assigned to light (L), moderate (M), and heavy (H) groups. Thermal images were taken pre- and post-standard exercise and underwent conventional and texture analysis. Texture analysis required image decomposition into red, green, and blue components. Among 372 returned features, 95 HS features, 48 GLRLM features, and 96 GLCH features differed dependent on exercise; whereas 29 HS features, 16 GLRLM features, and 30 GLCH features differed dependent on bodyweight ratio. Contrary to conventional thermal features, the texture heterogeneity measures, InvDefMom, SumEntrp, Entropy, DifVarnc, and DifEntrp, expressed consistent measurable differences when the red component was considered.
... The effect of a rider's bodyweight (BW) on the health, performance, and welfare of horses is frequently debated in studies of horse-rider relationships [13]. Increased rider weight has a negative effect on biomechanical, physiological, biochemical, and behavioral parameters of horses during exercise [11,21,22,24]. The weight a horse can carry is important, and it depends upon a number of physical traits, including size, age, body condition score, body conformation, duration of work, third metacarpal bone circumference, type of work, and the intensity of the work to be performed [24]. ...
... Increased rider weight has a negative effect on biomechanical, physiological, biochemical, and behavioral parameters of horses during exercise [11,21,22,24]. The weight a horse can carry is important, and it depends upon a number of physical traits, including size, age, body condition score, body conformation, duration of work, third metacarpal bone circumference, type of work, and the intensity of the work to be performed [24]. Overall this subject is poorly studied [24], and most research has been undertaken on Icelandic horses, which are traditionally subjected to a high rider:horse bodyweight ratios as compared to larger Warmblood horses and are also exposed to higher exercise intensities than ordinary riding horses [25]. ...
... The weight a horse can carry is important, and it depends upon a number of physical traits, including size, age, body condition score, body conformation, duration of work, third metacarpal bone circumference, type of work, and the intensity of the work to be performed [24]. Overall this subject is poorly studied [24], and most research has been undertaken on Icelandic horses, which are traditionally subjected to a high rider:horse bodyweight ratios as compared to larger Warmblood horses and are also exposed to higher exercise intensities than ordinary riding horses [25]. One factor that should be considered is that the impacts of mounted and harnessed loads are different, as the former is more energy demanding for a loaded trotting horse [26]. ...
Full-text available
Article
There are approximately 112 million working equids in developing countries, many of which are associated with brick kilns. Brick kilns and overloading are associated with welfare problems in working equids. Understanding equids’ abilities and influencing factors are important for both effective performance and welfare. Traditionally, measurement of the amount of ‘bone’ was used, and more recently, gait symmetry has been identified as a potential marker for loading capacity. Assessment of stride parameters and gait kinematics provides insights into adaptations to loading and may help determine cut-off loads. Physiological factors such as the ability to regain normal heart rates shortly after work is an important tool for equine fitness assessment and a more accurate measure of load-carrying capacity than absolute heart rate. Oxidative stress, plasma lactate, and serum creatine kinase activity are reliable biochemical indicators of loading ability. For monitoring stress, salivary cortisol is superior to serum cortisol level for assessment of hypothalamus-pituitary-adrenal axis and is related to eye temperatures, but this has yet to be interpreted in terms of load-carrying ability in equids. Further research is needed to standardize the evidence-based load-carrying capacity of working horses and donkeys.
... Since the rider's body weight was reported as a major factor that influencing physical exercise in horses [26], the effective rider's related horse load analysis approach has been requested. Powell et al. (2008) subjected the horses to a submaximal mounted standard exercise test under four conditions: carrying 15, 20, 25, or 30% of their body weight. They stated that horses carrying 10-15% of their body weight (about 50-75 kg of rider's body weight) demonstrate no physiological changes [27]. ...
... Powell et al. (2008) subjected the horses to a submaximal mounted standard exercise test under four conditions: carrying 15, 20, 25, or 30% of their body weight. They stated that horses carrying 10-15% of their body weight (about 50-75 kg of rider's body weight) demonstrate no physiological changes [27]. Then the maximal load for a horse has been suggested to not exceed 20% of horses body weight (about 100 kg of rider's body weight) [28,29], seeing that exceeding load constituting 25% of horses body weight (about 125 kg of rider's body weight) results in the basic physiological parameters increasing and post-exercise muscle pain [27,28]. ...
... They stated that horses carrying 10-15% of their body weight (about 50-75 kg of rider's body weight) demonstrate no physiological changes [27]. Then the maximal load for a horse has been suggested to not exceed 20% of horses body weight (about 100 kg of rider's body weight) [28,29], seeing that exceeding load constituting 25% of horses body weight (about 125 kg of rider's body weight) results in the basic physiological parameters increasing and post-exercise muscle pain [27,28]. Wilk et al. (2020) applied thermographic imaging to determining differences in SBT distribution between horses ridden by two riders with varied body weight (rider's body weight with saddle (kg)/% body weight of horse: LBW rider 50 kg/10.6%; ...
Full-text available
Article
Background The horses’ backs are particularly exposed to overload and injuries due to direct contact with the saddle and the influence of e.g. the rider’s body weight. The maximal load for a horse’s back during riding has been suggested not to exceed 20% of the horses’ body weight. The common prevalence of back problems in riding horses prompted the popularization of thermography of the thoracolumbar region. However, the analysis methods of thermographic images used so far do not distinguish loaded horses with body weight varying between 10 and 20%. Results The superficial body temperature (SBT) of the thoracolumbar region of the horse’s back was imaged using a non-contact thermographic camera before and after riding under riders with LBW (low body weight, 10%) and HBW (high body weight, 15%). Images were analyzed using six methods: five recent SBT analyses and the novel approach based on Gray Level Co-Occurrence Matrix (GLCM) and Gray Level Run Length Matrix (GLRLM). Temperatures of the horse’s thoracolumbar region were higher (p < 0.0001) after then before the training, and did not differ depending on the rider’s body weight (p > 0.05), regardless of used SBT analysis method. Effort-dependent differences (p < 0.05) were noted for six features of GLCM and GLRLM analysis. The values of selected GLCM and GLRLM features also differed (p < 0.05) between the LBW and HBW groups. Conclusion The GLCM and GLRLM analyses allowed the differentiation of horses subjected to a load of 10 and 15% of their body weights while horseback riding in contrast to the previously used SBT analysis methods. Both types of analyzing methods allow to differentiation thermal images obtained before and after riding. The textural analysis, including selected features of GLCM or GLRLM, seems to be promising tools in considering the quantitative assessment of thermographic images of horses’ thoracolumbar region.
... The impact of rider weight on horse welfare, health and performance is frequently debated, especially as the human population gets heavier [1]. Previous studies have reported that horse behavioral, physiological and gait parameters can be negatively affected by increased rider weight [2][3][4][5]. However, the effects on horse welfare are likely influenced by many factors, such as horse fitness and muscle development, conformation, discipline (e.g., show jumping or dressage), exercise intensity, the rider's fitness, skill and balance as well as equipment used, e.g., saddle fit [5]. ...
... Stride parameters were also affected in that, e.g., the relative stance duration in trot increased when mounted and loaded [10]. In another study, Powell et al. [4] exposed eight horses-described as light type riding horses-to a riding test of a relatively high intensity where they carried 15%, 20%, 25% and 30% of their own bodyweight in a crossover study. The horses were ridden by one of three experienced riders, and additional weight was attached to the saddle. ...
... The horses were ridden by one of three experienced riders, and additional weight was attached to the saddle. The horses had increased heart rates, respiration rates and rectal temperatures post-exercise in the 25% and 30% treatment, as well as increased lactate concentrations and muscle soreness after the 30% treatment [4]. Finally, in a recent pilot study, Dyson et al. [5] exposed six warmblood horses to four riders of different weights (61-142 kg). ...
Full-text available
Article
Recent studies have reported significant alterations in horse physiological and gait parameters when exposed to increased rider weight during moderate to high intensity exercise. This study aimed to evaluate the effect of increased rider weight (+15% and +25% of the regular rider's bodyweight) on horse behavioral, physiological and gait symmetry parameters during a standard dressage test. Twenty rider-horse equipages performed the same test three times in a randomized, crossover design. Salivary cortisol (SC), heart rate (HR), heart rate variability (HRV), behavior and gait symmetry (GS) were measured. SC concentrations increased from baseline (p < 0.001), but there was no significant treatment effect (difference from baseline (ng/mL): Control: 0.21 ± 0.1; +15%: 0.37 ± 0.1; +25%: 0.45 ± 0.2, p = 0.52). Similarly, there were no overall treatment effects on HR or HRV variables (avg HR across treatments (bpm): 105.3 ± 1.3), nor on GS parameters. There was large individual variation in conflict behavior but no effect of weight treatment. We conclude that increasing the weight of the regular rider by 15% and 25% did not result in significant short-term alterations in the measured parameters. Maximum rider:horse weight ratios were 15-23% and the exercise intensity was relatively low; thus the results should not be extrapolated to other weight ratios and exercise intensities.
... However, an equine that is not properly conditioned will not be able to efficiently carry the weight during a working day, thereby affecting its balance and transportation capacity (Powell, Bennett-Wimbush, Peeples, & Duthie, 2008;Souza et al., 2016;Souza et al., 2015). Therefore, the morphological and functional assessment of load carriage capacity in working equids is important using indices that improve their wellbeing and avoid health problems, economic losses, and, consequently, a decrease in productivity (Burn, Dennison, & Whay, 2010;Corrales-Hernández et al., 2018;McManus et al., 2005). ...
... The weight corresponded to 2.2 times the length and 1.9 times the height. The thoracic height and TP were 1.9 and 2.1 times the NL of the animal, being an important measure for the animal's body balance, as some studies have suggested that mules bear 55% of the total load weight on their front legs (Powell et al., 2008). ...
... As reported by the owners, the mules carried approximately 13 sacks (162.5 kg) in 8-to 9-h working days with a break of between 1 and 2 weeks during the month, depending on the activity in the sugar mill. Some authors have recommended that working equids with optimal body conditions can support loads on their back between 33% and 50% of their BW (Powell et al., 2008). These loading values of >50% of BW on the back exceed the percentages of weight recommended for horses of the same weight. ...
Full-text available
Article
The application of morphofunctional measurements allows the selection of suitable animals to perform working activities and ensure that animal maximum capacities are not exceeded. Mules are commonly used by small farmers for agricultural work in mountain areas where the access is extremely difficult. We aimed to estimate the functionality indexes of working mules in mountain areas of the Colombian Central Andes. A total of 94 adult mules were evaluated for withers height, thoracic perimeter, body length, neck length, and body weight, which were used to determine the body index (BI), proportionality index (PI), and load carriage index (LCI). Descriptive statistics, analysis of correlations, and principal component analysis were performed. Males presented higher morphometric measurements than females. There was a negative correlation between BI with PI and LCI. The principal component analysis was able to merge characteristics in two components explaining 81.78% of the variance in the indexes. These results demonstrated that working mules in the studied area have morphometric characteristics that define them as mesolinear animals with a low frame and broad chest, and these characteristics can function as a guide to identify desirable conformation indices for working mules, determining values of adequate load, respecting animal welfare.
... Behaviour score 3 Other behavioural and performancerelated parameters Additional physiolgical parameters Normando et al. (2011) Questionnaire on problem behaviour walk, trot, canter long-term (years)stereotypies, problem behaviour walk, trot, canter ca. 5 min (x) xx (x)tongue colour, quantitiy of visible saliva Christensen (2013) head and neck postures walk, trot, canter 10 min x xx xx xrein tension Fazio et al. (2013) Therapeutic vs recreational riders walk 5 and 30 min after exercise Powell et al. (2008) Different weight loads trot, canter . xmuscle soreness, muscle tightness scores plasma lactate, serum creatine kinase activity Sloet van Oldruitenborgh Oosterbaan et al. (2006) head and neck postures trot, canter 6 min xxriders' subjective impression blood lactate, packed cell colume, pH, bicarbonate, pC02, Glucose, electrolytes, creatinine kinase, van Breda (2006) Dressage vs recreational horses halt after exercise for 10 min 30-45 min after test x xxtotal HF and LF von Competition vs training halt, walk, trot, canter before, 0, 15 min past test x xxx acute exercie Treadmill Indivi-duals' maxi-mum speed >2 min xxbeta-endorphin, oxygen uptake, blood leucocyte numbers and immune cell subsets, lymphocyte proliveration response De Rantere et al. (2007) Two different degrees of poll flexion Treadmill trot 7 min xxpO2, pCO2, HCO3, pH, BE, PCV, lactate, glucose Kienapfel (2011) head and neck postures Standing halt 10 sx McGreevy et al. (2012) double bridle with or without noseband Standing halt 10 minxfacial temperature Schmidt et al. (2010) Stages of initial riding training Lunging, riding, free halt, walk, trot, canter 10-20 min x x ...
... 00 2.2.2. Other endocrionological or humoral parameters Other stress-indicators that have been used in horses include (see also Table 1) plasma or blood lactate levels ( Powell et al., 2008;Fazio et al., 2013;Munsters et al., 2013), plasma ascorbic acid ( Baucus et al., 1990), prolactin ( Colborn et al., 1991), iodothyronine ( Medica et al., 2011), oestradial-17 ( Medica et al., 2011), serum creatin kinase activity ( Powell et al., 2008), packed cell volume (Sloet van Oldruitenborgh Oosterbaan et al., 2006), ACTH ( Ferlazzo et al., 2012;Fazio et al., 2013) and plasma-endorphin ( McCarthy et al., 1993;Gillham et al., 1994;McGreevy and Nicol, 1998;Ferlazzo et al., 2012) as well as various other parameters for example, related to blood chemistry (e.g., De Rantere et al., 2007) and immune function ( Malinowski et al., 2006). However, all these parameters are predominantly linked to physiological workload or other physiological processes in the body, and it is questionable to what extent, if any, these parameters can serve to detect psychological stress. ...
... 00 2.2.2. Other endocrionological or humoral parameters Other stress-indicators that have been used in horses include (see also Table 1) plasma or blood lactate levels ( Powell et al., 2008;Fazio et al., 2013;Munsters et al., 2013), plasma ascorbic acid ( Baucus et al., 1990), prolactin ( Colborn et al., 1991), iodothyronine ( Medica et al., 2011), oestradial-17 ( Medica et al., 2011), serum creatin kinase activity ( Powell et al., 2008), packed cell volume (Sloet van Oldruitenborgh Oosterbaan et al., 2006), ACTH ( Ferlazzo et al., 2012;Fazio et al., 2013) and plasma-endorphin ( McCarthy et al., 1993;Gillham et al., 1994;McGreevy and Nicol, 1998;Ferlazzo et al., 2012) as well as various other parameters for example, related to blood chemistry (e.g., De Rantere et al., 2007) and immune function ( Malinowski et al., 2006). However, all these parameters are predominantly linked to physiological workload or other physiological processes in the body, and it is questionable to what extent, if any, these parameters can serve to detect psychological stress. ...
Article
Stress is a generic concept describing the body’s reaction to external stimuli, including both physiological and psychological factors. Therefore, by definition, the assessment of psychological stress in the exercising horse encompasses the problem of teasing apart the psychological and physiological factors both of which result in stress responses. The present study reviews the existing literature on various measures of stress taken specifically in the context of equitation science. Particular attention has been paid to short-term effects, and commonly used measurements of short-term stress include heart rate, a number of heart rate variability parameters, blood or saliva cortisol levels, eye temperature, and various behaviour parameters including in particular behaviour patterns presumably indicative of conflict with the rider’s/trainer’s aids. Inspection of the individual studies’ results revealed that disagreement between these different measures of stress is commonplace. For physiological parameters, the largest proportion of agreement (i.e. both parameters simultaneously indicated either higher, insignificant or lower stress compared to a control treatment) was found for heart rate and heart rate variability parameters, while generally limited agreement was found for cortisol and cardiovascular parameters. It appears that cortisol levels may not be particularly useful for assessing/assessment of the valence of a situation in the exercising horse as cortisol levels are predominantly linked to activation and exercise levels. Although heart rate variability parameters reflect in theory more closely sympathovagal balance compared to cortisol levels, great care has to be taken regarding the use of appropriate time-frames, appropriate raw data correction methods as well as the use of appropriate equipment. In spite of its wide-spread and apparently successful use, popular equipment may in fact not be accurate enough under field conditions. Eye temperature is another promising parameter for assessment of psychological stress, but the technique is likewise susceptible to application errors. Given the high susceptibility of physiological parameters to errors at various experimental stages, behavioural rather than physiological parameters may in fact provide more accurate measures of valence when conducting experiments in the exercising horse. Behavioural parameters that appear to be particularly practical in assessing stress in ridden horses’ behaviour are associated with? frequencies of behaviour indicative of conflict. However, while increased frequencies of aare a good indicator of stress, the absence of conflict behaviour does not provide proof of the absence of stress due to the possible occurrence of xxxx conditions such as Learned Helplessness. In future studies, the above issues should be taken into consideration when designing experiments to assess psychological stress in ridden horses.
... However, some riders of Icelandic horses weigh over 100 kg, corresponding to~30% to 35% of BW (Stefánsdóttir et al., 2014). Powell et al. (2008) showed that horses carrying a rider corresponding to 25% or 30% of their BW had higher heart rate (HR), breathing frequency (BF) and rectal temperature (RT) than when carrying a rider corresponding to 15% and 20% of their BW. Therefore it is a welfare issue to create knowledge on how the BW of a rider affects physiological response to exercise in the Icelandic horse. ...
... As hypothesized, the physiological response of the horses increased as BWR increased from 20% to 35%. These results are in accordance with the fundamental laws of physics (Newton's second law), and also in accordance with results on weight carrying in other riding horses (Thornton et al., 1987;Sloet van Oldruitenborgh-Oosterbaan et al., 1995;Powell et al., 2008). However, to the best of our knowledge this is the first study to measure the physiological response Effect of rider weight on horse physiology to increased BWR in Icelandic horses and also the first study to assess a weight threshold at which lactate rapidly accumulates (W 4 ) in a group of horses. ...
... Dobec et al. (1994) have suggested that the size of the M. longissimus is correlated to performance in Standardbred horses (the larger the better), but this could not be verified by Ringmark et al. (2015). However, the suggestion that back conformation affects weight carrying ability is also supported by observations by Powell et al. (2008), who found that post exercise muscle soreness was worse in horses with narrower loins. It would be of interest to collect more data on the relationship between the muscle conformation of the topline (back, loin and croup), limbs, trunk (sides of the body) and underline, and the weight carrying capacity of horses. ...
Full-text available
Article
This study examined the effect of increasing BW ratio (BWR) between rider and horse, in the BWR range common for Icelandic horses (20% to 35%), on heart rate (HR), plasma lactate concentration (Lac), BWR at Lac 4 mmol/l (W4), breathing frequency (BF), rectal temperature (RT) and hematocrit (Hct) in Icelandic horses. In total, eight experienced school-horses were used in an incremental exercise test performed outdoors on an oval riding track and one rider rode all horses. The exercise test consisted of five phases (each 642 m) in tölt, a four-beat symmetrical gait, at a speed of 5.4±0.1 m/s (mean±SD), where BWR between rider (including saddle) and horse started at 20% (BWR20), was increased to 25% (BWR25), 30% (BWR30), and 35% (BWR35) and finally decreased to 20% (BWR20b). Between phases, the horses were stopped (~5.5 min) to add lead weights to specially adjusted saddle bags and a vest on the rider. Heart rate was measured during warm-up, the exercise test and after 5, 15 and 30 min of recovery and blood samples were taken and BF recorded at rest, and at end of each of these aforementioned occasions. Rectal temperature was measured at rest, at end of the exercise test and after a 30-min recovery period. Body size and body condition score (BCS) were registered and a clinical examination performed on the day before the test and for 2 days after. Heart rate and BF increased linearly (P
... According to Powell et al. (2008), heart rates, respiration rates and rectal temperatures of light riding horses trotting at 4.8 km followed by cantering at 1.6 km were higher when carring 25% and 30% of their body weight than those with 15% and 20% weight carriage. Similarly, they reported that the horses tended to have greater changes in muscle soreness and muscle tightness when carrying 25% of their body weight, and significant changes in soreness and tightness scores were found in horses carrying 30% of their body weight (Powell et al. 2008). ...
... According to Powell et al. (2008), heart rates, respiration rates and rectal temperatures of light riding horses trotting at 4.8 km followed by cantering at 1.6 km were higher when carring 25% and 30% of their body weight than those with 15% and 20% weight carriage. Similarly, they reported that the horses tended to have greater changes in muscle soreness and muscle tightness when carrying 25% of their body weight, and significant changes in soreness and tightness scores were found in horses carrying 30% of their body weight (Powell et al. 2008). On the other hand, Sloet van Oldruitenborgh-Oosterbaan et al. (1995) showed that a load between 12.6% and 16.3% of the horse's body weight influenced heart rate and blood lactate concentration compared with the horse working unloaded in the case of Dutch Warmblood horses at trot on a treadmill. ...
... The estimation in the present study agrees with the results obtained by Powell et al. (2008) and the rule of the Japanese Imperial Army and is lower than results obtained by Hadrill (2002). Estimation by the RDA Japan, which is between 16% and 17%, is much lower than our estimation, probably because of the consideration for safety of both the disabled rider and the side-walker who helps the rider from both sides of the horse. ...
Full-text available
Article
The aim of this study was to establish a method for estimating loading capacity for Japanese native horses by gait analysis using an accelerometer. Six mares of Japanese native horses were used. The acceleration of each horse was recorded during walking and trotting along a straight course at a sampling frequency of 200 Hz. Each horse performed 12 tests: one test with a loaded weight of 80 kg (First 80 kg) followed by 10 tests with random loaded weights between 85 kg and 130 kg and a final test with a loaded weight of 80 kg again. The time series of acceleration was subjected to fast Fourier transformation, and the autocorrelation coefficient was calculated. The first two peaks of the autocorrelation were defined as symmetry and regularity of the gait. At trot, symmetries in the 100, 110, and 125 kg tests were significantly lower than that in First 80 kg (P < 0.05, by analysis of covariance and Sidak's test). These results imply that the maximum permissible load weight is less than 100 kg, which is 29% of the body weight of Japanese native horses. Our method is a widely applicable and welfare-friendly method for estimating maximum permissible load weights of horses.
... As the bodyweight of the horse riders increases [7,11,14], an increasing load negatively impacts the health of the horse's back [15], physical exercise of the horse [16,17], and horse welfare [18]. Therefore, the appropriate fit of rider size to the horse size is becoming increasingly important in riding horse usage [19,20]. ...
... Therefore, the greatest changes noted currently in the red and blue color components are in line with conventional thermal results, where two temperature measures, the minimal and maximal, differed both between effort states [33,64] and different rider bodyweights [20,21,34]. Those differences reflect the thermal energy emission increase with the increase in metabolic energy produced by loaded muscle units [15,16,67,68]. Interestingly, as the DispEn algorithm returned entropy measures that were not very sensitive to rotation, translation, or image size [57], DispEn may be applicable in smaller or larger image areas, unlike the entropy-related GLCM texture features [20]. ...
Full-text available
Article
As obesity is a serious problem in the human population, overloading of the horse’s thoracolumbar region often affects sport and school horses. The advances in using infrared thermography (IRT) to assess the horse’s back overload will shortly integrate the IRT-based rider-horse fit into everyday equine practice. This study aimed to evaluate the applicability of entropy measures to select the most informative measures and color components, and the accuracy of rider:horse bodyweight ratio detection. Twelve horses were ridden by each of the six riders assigned to the light, moderate, and heavy groups. Thermal images were taken pre- and post-exercise. For each thermal image, two-dimensional sample (SampEn), fuzzy (FuzzEn), permutation (PermEn), dispersion (DispEn), and distribution (DistEn) entropies were measured in the withers and the thoracic spine areas. Among 40 returned measures, 30 entropy measures were exercise-dependent, whereas 8 entropy measures were bodyweight ratio-dependent. Moreover, three entropy measures demonstrated similarities to entropy-related gray level co-occurrence matrix (GLCM) texture features, confirming the higher irregularity and complexity of thermal image texture when horses worked under heavy riders. An application of DispEn to red color components enables identification of the light and heavy rider groups with higher accuracy than the previously used entropy-related GLCM texture features.
... Relating conformation and performance, Powell et al [40] reported that horses with wider loins and greater cannon circumference showed less back soreness after carrying heavy riders. Ponies are generally more stocky than horses and this likely contributes to the fact that Taishuh ponies and Icelandic horses are able to carry relatively heavier weights than larger breeds of horses without a change in stride symmetry. ...
... Icelandic horses t€ olting at 5.4 m/second rely mainly on aerobic metabolism until the BWR reaches a mean value of 22.7% [43]. In riding horses carrying 20%e 35% BWR, heart rate increased when BWR increased from 20% to 25%, postexercise plasma lactate was higher at 30% BWR, and the back muscles started to become painful to palpation at 25% BWR [40]. ...
Article
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.
... The body weight (BW) of a rider is believed to have a major influence on the impact of physical exercise in horses [2]. As reported by Powell et al. [3], horses demonstrate no physiological changes while carrying 10-15% of their BW, which means about 50-75 kg of rider's BW. Only when the load exceeds 25% of their BW do changes become visible, such as an increase in the basic physiological parameters and post-exercise muscle pain, as well as increased activity of the sympathetic nervous system [3,4]. ...
... As reported by Powell et al. [3], horses demonstrate no physiological changes while carrying 10-15% of their BW, which means about 50-75 kg of rider's BW. Only when the load exceeds 25% of their BW do changes become visible, such as an increase in the basic physiological parameters and post-exercise muscle pain, as well as increased activity of the sympathetic nervous system [3,4]. Therefore, the results of the cited studies indicate that the load for a horse should not exceed 20%. ...
Full-text available
Article
It was assumed that a horse with its rider body weight found in the upper limit may negatively impact the horse’s welfare. The objective of this paper was to analyze the differences in body temperature and selected heart rate parameters in horses in response to physical exercise accompanied by various rider’s body weight loads. The study was carried out on 12 leisure, 10–15-year-old warmblood geldings. The horses were ridden by two equally qualified riders whose body weights were about 20% and 10% of the average body weight (BW) of the animals (about 470 kg). Each rider rode each of the 12 horses for 13 min walking and 20 min of trotting. Images of the horse at rest, after physical exercise directly after unsaddling, and during the recovery phase (10 min after unsaddling) were taken with an infrared thermography camera. For analysis, the temperatures of selected body parts were measured on the surface of the head, neck, front, middle, and back (croup) parts of the trunk, forelimb, and hind limb. Immediately after the infrared thermography images were taken, the rectal temperature of the horse was measured. The heart rate parameters were measured at rest for 10 min directly before, during, and 10 min following the end of a training session. A multivariate analysis of variance (ANOVA) for repeated measurements was performed. Statistical significance was accepted for p < 0.05. A rider BW load on a horse of approximately 20% of the horse’s BW led to a substantial increase in the superficial temperatures of the neck, front, middle, and back parts of the trunk in relation to these body parts’ average temperatures when the load was about 10% BW. The head and limb average temperatures were not significantly affected by the load of the exercised horse. A horse’s load above 20% of his body weight, even with little effort, affects changes in surface temperature and the activity of the autonomic nervous system.
... Studies investigating rider weight have been performed (Sloet van Oldruitenborgh-Oosterbaan et al. 1995;Powell et al. 2008;Matsuura et al. 2013aMatsuura et al. ,b, 2016Gunnarsson et al. 2017;Stef ansd ottir et al. 2017), but few have satisfactorily addressed this issue in a typical riding situation. They have, for example, utilised lead weights to alter the total load carried (Matsuura et al. 2013a(Matsuura et al. ,b, 2016Gunnarsson et al. 2017), which does not address potential differences in physique and balance in riders of differing weights, or treadmill exercise (Sloet van Oldruitenborgh-Oosterbaan et al. 1995), which does not necessarily equate with overground exercise, and does not include turns and circles. ...
... There are anecdotal suggestions that horses with greater circumference of the metacarpal region (i.e. more 'bone') are capable of carrying more weight than horses with less 'bone'. In a study of eight unfit horses ridden by one of three experienced riders plus lead (total weight, 15, 20, 25 and 30% of horse bodyweight), metacarpal region circumference was negatively associated with muscle soreness and tightness after a 45-min exercise test (Powell et al. 2008). However, this study was of low power and therefore the conclusions are questionable. ...
Full-text available
Article
The effect of rider weight on equine welfare and performance requires further investigation. The objective of this prospective, cross‐over, randomised trial was to assess gait and behavioural responses of horses to riders of similar ability, but different bodyweights. Six nonlame horses in regular work were ridden by each of four riders: Light (L), Moderate (M), Heavy (H) and Very Heavy (VH). Saddle fit was assessed subjectively throughout the study. Each horse was ridden twice by riders L and M, and once by rider H. Rider VH rode five horses once and one twice. Each horse‐rider combination undertook a standardised, 30‐min ‘dressage‐test' which was abandoned if we observed lameness grade ≥ 3/8 in one limb, grade ≥ 2/8 in ≥ 2 limbs, or ≥ 10/24 behavioural markers of pain. Horses were reassessed in hand 45–60 min after any abandonment. Mean rider bodyweights, body mass index (BMI) values and rider:horse bodyweight percentages for the L, M, H and VH riders were respectively: 60.8, 77.8, 91.0, 142.1 kg; 23.2, 28.0, 26.3, 46.9 kg/m2; 10.0–11.7%, 12.8–15.0%, 15.3–17.9%, 23.6–27.5%. All 13 H and VH rider tests (lameness, n = 12; behaviour, n = 1) and one of 12 M rider tests (lameness) were abandoned. Lameness was confirmed using inertial measurement unit data. All horses trotted sound after test abandonment and completed the study moving well when ridden. Limitations of the study were saddle fit was not ideal in all horse‐rider combinations and abandonment criteria were subjective. The conclusions and clinical relevance of the study were that large riders can induce temporary lameness and behaviours consistent with musculoskeletal pain. This may relate to rider bodyweight and/or weight distribution. Riders M and H had similar BMI but markedly different test abandonment rates, therefore bodyweight is likely to be more relevant than BMI. Further work is required to determine if horse fitness, adaptation to heavier weights and better saddle fit for heavier/taller riders will increase horses' weight‐carrying capacity.
... Additionally, it is widely recognized that both humans (Dupuy, Douzi, Theurot, Bosquet, & Dugue, 2018) and animals (Libert, Adams, Betancourt, Horohov, & McKeever, 2010) will experience muscle micro-damage, often resulting in delayed onset of muscle soreness (DOMS), when performing unaccustomed or excessive muscular contractions. A muscle soreness and tightness scoring system based on manual manipulations was described by Powell, Bennett-Wimbush, Peeples, and Duthie (2008), and increases in muscle soreness and tightness were positively correlated with plasma lactate and serum creatine kinase activity, indicative of muscle damage. In order to Figure 1. ...
... Additionally, before the start of each 90TT, and 24 hours after each 90TT, the degree of muscle soreness and tightness was scored by the same professional animal massage therapist, blinded to the treatments. A Likert-type subjective scoring system described by Powell et al. (2008) was used to evaluate muscle soreness and tightness. Briefly, 20 sites (10 on the right and 10 on the left) were evaluated on a 0.5 gradient scale from 0 to 2.5, for muscle soreness (MSS) and muscle tightness (MTS), separately. ...
Article
Three sequential studies were performed to evaluate the effects of tying horses while wearing overchecks (strap from the bridle to backpad). In an observational study, horses (n = 305) wore high (HC), low (LC), or no overchecks (NC) with frequencies of 29.2%, 51.8% and 19.0% respectively. Study 1 (Latin square, n = 6) consisted of a 90-min tie test (90TT) with treatments (HC, LC, NC) x periods (1–3). Horses wearing HC had higher plasma cortisol (P < 0.01) when compared to LC and NC. Muscle soreness (MSS) and tightness (MTS) were evaluated pre and 24 hr post 90TT and were higher (P < 0.01) 24 hrs after 90TT regardless of treatment. In study 2, in order to determine if acclimation to tying with overchecks could reduce the cortisol response in study 1, horses (n = 6) were tied 60 minutes/day for 2 weeks followed by a 60-min TT (60TT). Neither plasma cortisol nor heart rate were elevated above baseline levels, suggesting adaptation to novel stressors. Tying with restrictive HC appears to be a stressor, which may be reduced if an adaptation period is provided.
... However, these values have little scientific basis, and only five studies of this nature have been reported so far. According to Powell et al. (2008), heart and respiratory rates and rectal temperature were higher in horses carrying loads representing 25-30% of their bodyweight compared to those carrying 15-20%. Similarly, Sloet van Oldruitenborgh-Oosterbaan et al. (1995) demonstrated that a load representing 12.6-16.3% of bodyweight significantly influenced heart rate and blood lactate concentration compared with no load at all. ...
... In consideration of the weight of a saddle, the maximum bodyweight of the rider for a Kiso horse should be 110 kg under trotting conditions. These results are in close agreement with previous figures reported by Powell et al. (2008) estimating a maximum permissible load weigh of 25-30% of bodyweight. Our previous studies showed that the maximum permissible load weight of the Taishuh pony trotting at 3.0 m/s over a short distance was < 100 kg, which is 43% of bodyweight (Matsuura et al. 2013b). ...
Article
This study aimed to determine the load-bearing capacity of trotting Kiso horses using gait analysis. Ten Kiso horses with a height at withers of 128 cm were included. Their riders were fitted with a marker (70 mm in diameter placed on their chest) recorded by two digital DVD cameras while trotting along a short, straight course. In total, eight tests were performed for each horse: the first with a 70 kg load; six with randomly loaded weights ranging 80–130 kg; and then a final test again with a 70 kg load. Three-dimensional movement of the marker was analyzed using a motion capture system. The time series of vertical displacement of the marker underwent spectrum analysis by the maximum entropy method, and the autocorrelation coefficient was calculated. The first two peaks of the autocorrelation were defined as symmetry and regularity, and their sum was defined as stability. Regularity in the 120 kg test (0.54) was lower than that in the first 70 kg test (0.61), and stability in the 120 kg test (1.31) was lower than that in the first 70 kg test (1.42). We concluded that the maximum permissible load for a trotting Kiso horse is < 120 kg, which represents 31% of its bodyweight.
... To our knowledge, there are 3 studies based on scientific evidence. According to Powell et al. (2008), heart rates, respiration rates and rectal temperatures were higher when horses carried loads that were 25 and 30% of their BW than those carrying loads of 15 and 20%. Sloet van Oldruitenbourgh-Oosterbaan et al. (1995) showed that a load between 12.6 and 16.3% of BW influenced heart rate and blood lactate concentration compared with no load. ...
... The estimation in the present study agrees with the suggestion by Hadrill et al. (2002) of between one-third and one-half of the BW of the horse. The estimation in the present study is greater than the results obtained by Powell et al. (2008) of between 25 and 30% of the BW and those obtained by Matsuura et al. (2013) of 29% of the BW. Moreover, the recommendation in the current study is much greater than those obtained by RDA Japan of between 16 and 17% of the BW and those obtained by Sloet van Oldruitenbourgh-Oosterbaan et al. (1995) of between 12.6 and 16.3% of BW. ...
Full-text available
Article
The aim of this study was to determine the loading capacity of a trotting Taishuh pony by gait analysis using a motion analysis system. Seven Taishuh Ponies (five mares and two geldings) and their rider were fitted with a marker (70 mm in diameter placed on their chest) and recorded by two high-resolution digital DVD cameras (at a sampling frequency of 60 Hz) while trotting along a straight course. Each horse performed seven tests: one test with a loaded weight of 70 kg, five tests with random loaded weights between 80 kg and 120 kg, and a final test with a loaded weight of 70 kg again. Three-dimensional movements of each marker were analyzed using motion capture system. The time series of the vertical displacements of the marker was subjected to spectrum analysis by the maximum entropy method, and the autocorrelation coefficient was calculated. The first two peaks of the autocorrelation were defined as symmetry and regularity of the gait, and the sum of symmetry and regularity was defined as stability. The cross-spectrum analysis (Blackman-Tukey method) also was performed to analyze the time lag and cross-correlation coefficient between the time series of both pony and rider. Among ponies, symmetry in the 120 kg test (0.54) was significantly lower than that in the first 70 kg test (0.75, P < 0.05) and stabilities in the 100 kg (1.17) and 120 kg (1.17) tests were significantly lower than that in the first 70 kg (1.46, P < 0.05). Regarding the rider, there were no significant differences in symmetry, regularity, and stability between loaded weights. The time lag between the time series of horse and rider in the 120 kg test (47.6 msec) was significantly greater than that in the first 70 kg (14.3 msec, P < 0.05) test. These results suggests that the maximum permissible load weight of the Taishuh pony trotting at 3.0 m/s over a short distance was less than 100 kg, which is 43% of the body weight.
... Other indicators that have been employed with equines include blood glucose [104], and lactate levels [114], serum creatine kinase [115], and plasma beta-endorphin [116,117], but these parameters are not exclusive for detecting stress [20,97]. Therefore, an endocrinal response can be an indicator of anxiety and pain that could even help to identify when it is a chronic or acute event by considering the indicators involved. ...
Full-text available
Article
Pain and anxiety are two of the most important concerns in clinical veterinary medicine because they arise as consequences of multiple factors that can severely affect animal welfare. The aim of the present review was to provide a description and interpretation of the physiological and behavioral alterations associated with pain and anxiety in equines. To this end, we conducted an extensive review of diverse sources on the topic. The article begins by describing the neurophysiological pathway of pain, followed by a discussion of the importance of the limbic system in responses to pain and anxiety, since prolonged exposure to situations that cause stress and pain generates such physiological changes as tachycardia, tachypnea, hypertension, hyperthermia, and heart rate variability (HRV), often accompanied by altered emotional states, deficient rest, and even aggressiveness. In the long term, animals may show deficiencies in their ability to deal with changes in the environment due to alterations in the functioning of their immune, nervous, and endocrinologic systems. In conclusion, pain and anxiety directly impact the homeostasis of organisms, so it is necessary to conduct objective evaluations of both sensations using behavioral scales, like the horse grimace scale, complemented by assessments of blood biomarkers to analyze their correlation with physiological parameters: Heart rate, respiratory rate, HRV, the parasympathetic tone activity index, lactate and glucose levels, and temperature. Additional tools – infrared thermography, for example – can also be used in these efforts to improve the quality of life and welfare of horses.
... These findings agree with studies in horses where stride parameters such as the symmetry and range of limb movements were not affected by carrying extra loads. For example, carrying weights up to 30% of body mass in Arabian horses [22], 29% in Japanese native horses [23], and 25% in light horses [24,25] resulted in no noticeable effects on behavior or physiological parameters, such as heart rates and plasma lactate concentrations. Therefore, it could be implied that for elephants, carrying 15% of body mass loads does not impact musculoskeletal function, at least during short walking bouts on flat terrain. ...
Full-text available
Article
Background: Elephants in Thailand have changed their roles from working in the logging industry to tourism over the past two decades. In 2020, there were approximately 2700 captive elephants participating in activities such as riding and trekking. During work hours, riding elephants carry one or two people in a saddle on the back with a mahout on the neck several hours a day and over varying terrain. A concern is that this form of riding can cause serious injuries to the musculoskeletal system, although to date there have been no empirical studies to determine the influence of weight carriage on kinematics in elephants. Methods: Eight Asian elephants from a camp in Chiang Mai Province, Thailand, aged between 21 and 41 years with a mean body mass of 3265 ± 140.2 kg, were evaluated under two conditions: walking at a normal speed without a saddle and with a 15% body mass load (saddle and two persons plus additional weights). Gait kinematics, including the maximal angles of fore- and hindlimb joints, were determined using a novel three-dimensional inertial measurement system with wireless sensors. Results: There were no statistical differences between movement angles and a range of motion of the fore- and hindlimbs, when an additional 15% of body mass was added. Conclusion: There is no evidence that carrying a 15% body mass load causes significant changes in elephant gait patterns. Thus, carrying two people in a saddle may have minimal effects on musculoskeletal function. More studies are needed to further test longer durations of riding on different types of terrain to develop appropriate working guidelines for captive elephants. Nevertheless, elephants appear capable of carrying significant amounts of weight on the back without showing signs of physical distress.
... In light of the concern regarding the effect or the rider's weight on the horse's wellbeing, it is reassuring that the average ratio between the rider and horse weight was 12 ± 2.3%, which has been classed as "light" in recent studies [27,28] and is below the commonly recommended 15% to 20% (e.g., [29]). ...
Article
The use of horses in competitive sports receives increasing criticism from the public, mainly due to the potential for injury. However, it is unclear if orthopaedic and other health issues are more common in competition horses when compared to leisure horses. The aim of this study was to assess husbandry, use, and orthodpeadic health in Swiss riding horses, and to compare these aspects between horses owned by self-identified competitive (CR) and leisure riders (LR) in Switzerland. 237 owners completed an online survey providing information on their athletic ambitions, their horse’s husbandry, health, training, and tack. Two experienced veterinarians assessed gait irregularities, muscular development, and back pain in the horses, and evaluated saddle fit. Compared to horses owned by competitive riders (CH), a higher proportion of horses kept by leisure riders (LH) were kept unshod, under more natural conditions, and turned out with other horses. LH were exercised less frequently and LR trained less frequently with instructors. CR reported more frequent saddle checks and the use of more training aids during riding. No differences between the two groups could be found in orthopaedic health, muscular development, or back pain, but LH had higher BCSs and a slightly higher proportion of saddles with at least one fit problem. Our data revealed no increased prevalence of the assessed health problems in competition horses compared to leisure horses in Switzerland. However, suboptimal saddle fit and muscular development, back pain, and gait irregularity are frequent in both groups and deserve more attention.
... As the greatest part of the forelimb to support body weight (BW), the cannon bone has the greatest growth rate in length from birth to 10 weeks of age, after which length remains stable (Quarter Horse data [10,11]. Circumference of the front cannon bone can also be used to estimate the strength and mineral content of the bone [12]. ...
Article
Our objective was to determine the influence of season (winter, spring, summer, and fall) on travel patterns, hoof growth, and longissimus dorsi muscle (LM) height and fat thickness between 13th and 14th ribs in 16 horses aged <4 years (eight males and eight females) of Morgan, Quarter Horse, and Moriesian breeds. Real-time ultrasound images of LM height and fat thickness as well as measures of hoof growth were obtained at the end of each season. Global positioning system tracking was conducted for four randomly selected days and one storm day in each season. Data were analyzed using a linear mixed model procedure in SAS. Season influenced fat deposition (P < .01) with the greatest increase in fall (P < .05) but had minimal effect on muscle growth. Hoof growth was greatest in summer and least in winter (P < .01). The average distance traveled was greater in spring and summer than in fall and winter (P < .01). The horses moved for less time and traveled less distance on storm days (P < .05) compared with nonstorm days. Young horses also traveled less on storm days, which indicates that it may be especially important to provide shelter for them. It was concluded that season influenced fat deposition, distance traveled, and hoof growth of domestic young horses. A better understanding of these factors could help equine professionals manage young horses more efficiently to benefit the horses' physical well-being.
... Différentes études ont montré l'impact des techniques d'équitation sur les douleurs ressenties potentiellement par le cheval : la hauteur des mains du bénéficiaire, l'utilisation d'un mors avec des mouvements de main incontrôlés, des rênes tendues, de la monte à deux (bénéficiaire et intervenant à l'arrière) ou encore où le bénéficiaire se place sur le cheval et son poids sont autant d'aspects à bien considérer. Ainsi, des chercheurs recommandent que le poids du cavalier n'excède pas 25 à 30% du poids du cheval (Powell et al., 2008). De façon intéressante, en dehors ce que les auteurs considèrent comme « la qualité de vie », aucune étude n'a été menée sur le bien-être des personnes avec TSA. ...
Article
La pratique de médiation équine pour les personnes avec troubles du spectre autistique (TSA) connait une expansion depuis plus d'une décennie en France. Pour autant, il apparait nécessaire de s'intéresser aux connaissances scientifiques sur cette question, qui restent rares, notamment sur l'impact de la pratique sur le cheval et sur l'humain. Cette contribution se propose, avec l'angle de l'éthologie, de faire le point sur les bénéfices réels pour l'humain, de l'impact sur le cheval et son bien-être, et de proposer des pistes de réflexion pour optimiser la pratique de médiation équine. Mots-clés : cheval, médiation équine, trouble du spectre autistique, éthologie. Equine assisted interventions for people with autism spectrum disorders (ASD) are more and more widespread in France. Nevertheless, scientific studies on this topic remain scarce, especially on practice effects on horses and on humans. Our paper proposes, using ethological point of view, to review real benefits of the practice on humans, of effects on horse welfare, and to give lines of thought. Taken together, it could help to improve equine assisted interventions.
... Several studies (Sloet van Oldruitenborgh-Oosterbaan et al. 1995;Powell et al. 2008;Matsuura et al. 2013aMatsuura et al. ,b, 2016Gunnarsson et al. 2017;Stef ansd ottir et al. 2017) have investigated the effect of the weight of a rider with additional dead weight on the gait characteristics of horses and other physiological parameters. However, no previous studies have specifically compared the effect of riders of varying weights or heights on force magnitude and pressure distribution under the saddle during over ground exercise in both straight lines and circles. ...
Article
There is limited scientific evidence concerning the effect of rider weight on pressures under the saddle and equine performance. The objective of this prospective, crossover, randomised trial was to assess pressure distribution and magnitude in horses ridden by four riders of similar ability but differing in bodyweight and height. Six horses in regular work were ridden by four riders (rider bodyweight: horse body weight percentage > 10 ≤ 12 [L = Light], > 12 ≤ 15 [M = Moderate], > 15 ≤ 18 [H = Heavy] and > 20 [VH = Very Heavy]), performing a purpose‐designed dressage test (30 min). The test was abandoned for ≥ grade 3/8 lameness or ≥ 10 behavioural markers (assessed in real‐time). A calibrated force mat (Pliance) was used to record pressures under the saddle in walk, trot and canter on left and right reins. Rider position was assessed. All 13 H and VH tests and one of 12 M rider tests were abandoned (lameness, n = 12; behaviour, n = 1). At walk, the seat of rider VH extended beyond the cantle of the saddle; rider H sat on the cantle of the saddle. At trot and canter the heels of rider VH were consistently cranial to the tubera coxae and shoulders. Pressures were significantly higher under the caudal aspect of the saddle compared with cranially for rider VH in walk (P<0.05, ANOVA, Bonferroni). At rising trot pressures were higher cranially for riders L, M and H (P<0.05, ANOVA, Bonferroni), but were similar cranially and caudally for rider VH. The highest maximum peak pressure was recorded for rider VH in canter. A limitation was that speed can alter pressure measurements, but was not controlled or recorded. We concluded that there were differences in magnitude and distribution of pressures among the four riders according to their size, which may have contributed to the development of musculoskeletal pain. This may also have been influenced by saddle fit for riders and their positions.
... As the greatest part of the forelimb to support body weight (BW), the cannon bone has the greatest growth rate in length from birth to 10 weeks of age, after which length remains stable (Quarter Horse data [10,11]. Circumference of the front cannon bone can also be used to estimate the strength and mineral content of the bone [12]. ...
... Both Feh and De Mazières (1993) and Normando et al. (2002) used treatment lengths of 3 min of grooming around the wither area and thus may have allowed time for physiological parameters to change; however, behaviors were not studied in either experiment to allow for comparison. Regardless, HR for horses during all three treatments was within a common reported range consistent with light work while under saddle (Matsuura et al., 2010;Powell, Bennett-Wimbush, Peeples, & Duthie, 2008). ...
Full-text available
Article
Riding is considered to be an arousing activity for horses. It has been suggested that wither scratching may be a more useful tool for relaxation compared with the common practice of neck patting. In the current study, 18 horses were exposed to 3 treatments, including control or no interaction, neck patting, and wither scratching, for 1 min each following a short obstacle course. Heart rate, heart rate variability, and a variety of behaviors were measured in the horses. Wither scratching produced a significantly longer duration of relaxed-type behaviors. Wither scratching could be a useful tool to help a horse relax while under saddle. Additionally, the study identified 2 ear positions that may be useful for future research in horse behavior.
Article
Hypothesis: The goal of this study was to evaluate the impact of three different adaptive devices used to facilitate therapeutic horseback riding for riders with cerebral palsy (CP), the horses, and the assisting persons. The study hypothesis was that there is no difference in clinical benefit to the rider; stress or physical saddle pressure to the horse; or the level of exertion required from assisting persons when using any of the three adaptive devices. Population: Individuals with varying disability due to cerebral palsy who participated in a therapeutic horseback riding program at a Professional Association of Therapeutic Horsemanship (PATH) Premier Accredited Center. Intervention: Therapeutic horseback riding sessions using one of three adaptive devices. Comparators: Two commonly used adaptive devices (English saddle and bareback pad with backrider), and one recently developed, less-used device (Independence saddle). Outcomes: Clinical benefit for the individual with Cerebral Palsy was evaluated using an osteopathic musculoskeletal exam score. Equine stress was evaluated using a horse stress behavior ethogram. Physical pressure under the saddle of the horse was evaluated using a Pliance Saddle pad under each adaptive device. Required level of exertion by assisting persons was measured using an assistant exertion score. Conclusion: Therapeutic riding using an English saddle, a backriding pad with backrider, or an Independence saddle, by individuals with various degrees of disability, does not cause excessive stress or result in excessive pressure to the horse. Using one assistive device over another also does not appear to change the likelihood of clinical benefit to the rider. However, exertion scores for assisting persons were lower when the Independence saddle was used compared to the English saddle or backriding pad. Adaptive devices that allow an individual with CP to improve function, ride more independently, provide some respite for the side walker and do not cause undue stress or frustration to the horse would be a great addition to the therapeutic regimen. Based on the results of this study, the Independence saddle is a viable alternative to the English saddle or the backriding pad for riders that would otherwise need extensive assisting person support in a therapeutic riding program.
Full-text available
Thesis
The underground salt mining in Hallstatt offers a unique range of finds. Previous re-search has dealt with the finds in the mine and its immediate surroundings, but not with the question of how salt and the supplies were transported. The subject of the work is the investigation of the means of transport in the period from the 13th till 11th century BC. The study was carried out by determining the available means of transport in the study area with regards to the topographical features of the region. Different models of transport on land and water were derived from this. Resulting in a calculation of the needed manpower for carrying out the transports to the first trading hubs which are ex-pected to have been near the city of Gmunden and in the Enns valley. Some aspects of resource management have also been considered.
Full-text available
Article
EXARC Journal Issue 2022/1 This study was undertaken to gain an understanding of the effectiveness of mail armour in protecting horses against arrow shot, and to assess the circumstances in which such armour might play a useful role. Since the protection given by mail is largely dependent on the thickness of the underlying padding, a preliminary step was to estimate the maximum thickness of padding that could be worn by the horse during cavalry operations. Experimental tests were then conducted by shooting arrows with reproduction medieval bodkin points at reproduction mail over various thicknesses of woven linen fabric. It was concluded that it would not be feasible to attain complete protection against arrows by mail armour and linen padding while remaining within the carrying capacity of horses for day-long operations. The fully-armoured medieval warhorse would probably have had a very limited role. The combined effect of weight and thermal loading meant that it could only perform effectively for relatively short periods. In engagements where remounts might be at hand, such as battles and tournaments, this was not a problem. However, for chevauchée type operations, which were likely to be carried out further afield and required sustained periods of speed and endurance, it would have proved counterproductive.1
Article
Horse riders in the UK have a legal responsibility for the welfare of the horses in their care, outlined by the Animal Welfare Act (2006). Understanding weight management factors that influence rider: horse bodyweight (RHBW) ratio is key to safeguarding horse welfare as human obesity rates increase. Recent high-profile incidents have seen riders being asked to dismount for being too heavy, demonstrating an awareness of the possible impact of excessive rider weight, threatening the equestrian industry’s social licence to operate. This study investigated RHBW trends within the UK leisure and amateur rider population to understand rider perception of ‘ideal’ RHBW and factors influencing rider and horse weight management. An online survey (SurveyMonkey®) was distributed via UK equine-related Facebook™ groups and collected information on horse and rider demographics, rider weight management strategies and respondents’ views on the importance of rider weight on horse welfare. Kruskal-Wallis analyses with Mann Whitney U post-hoc tests identified whether differences in respondent views differed between RHBW groups. A total of 971 riders completed the survey; respondents were aged between 18-65+ years old and 88% (n=953) were experienced riders. RHBWs were calculated for 764 (79%) of respondents as 21.2% (n=206) did not know either their own and/or their horses’ weight. Weight tapes (44.5%; n=432) and weigh bridges (29.5%; n=286) were common horse weight estimation methods. RHBWs ranged from 4.9% to 21.88%, mean: 12.5%±2.7%. Riders with lower RHBW thought about their own weight less and measured their horses’ weight less often than those with higher ratios (P<0.005, P<0.0004, respectively). The majority of riders who participated were weight conscious and recognised potential detrimental impacts associated with increased rider weight. Development of RHBW guidelines supported by equestrian governing bodies would highlight the need for riders to consider the impact of weight and support them in choosing suitable horses.
Full-text available
Article
Hippotherapy in patients with neuromuscular dysfunction creates high focal pressure on the pony's back due to bareback riding and asymmetrical riding position. This study aimed to investigate the acute effect of asymmetrical bareback riding on the pony's spinal kinematics, blood lactate, serum creatine kinase, heart rate, and temperament score. Eight ponies were selected, and they walked on a treadmill for 45 min in each experimental day including warm-up (5 min), weight loading by mannequin (30 min), and cool-down (10 min) sessions. During the weight loading session, three different weight distributions on the pony's back were applied between the left and right side: 50:50 (treatment M), 70:30 (treatment L) and 30:70 (treatment R) on the first, second, and third day of the experiment, respectively. The spinal kinematics at the end of weight loading session revealed the slight reduction in range of motion in both flexion-extension and lateral bending during treatment R. Stride length and stride duration had no differences between treatments. Level of blood lactate, serum creatine kinase and the back examination were normal. Heart rate and temperament score revealed that all ponies were calm throughout during loading a mannequin. This information concluded that asymmetrical bareback riding did not cause acute or serious back injury which encouraged the good equine welfare in ponies used for hippotherapy.
Article
Exercising horses are commonly plagued by muscle fatigue and soreness, which can result in reduced performance ability. In the present study, ten unconditioned horses were fed 200g per day DigestaWell® NRG, a commercial dietary supplement containing Yucca schidigera and Trigonella foenum-graecum, two herbs shown in other species to reduce post-exercise muscle pain and soreness. A control, unsupplemented group contained ten horses of similar age, breed, and gender. Horses completed a 50 min, ridden standardized exercise test of moderate intensity immediately prior to (Period1) and after 28 d of supplementation (Period2). Muscle soreness and tightness were evaluated 24 h prior to and after each exercise test and used to determine the percent increase in post-exercise muscle soreness and tightness. Blood samples were collected before, and at 10 and 30 min, and 1, 4, and 24 h post exercise. Plasma was analyzed for glucose, lactate, non-esterified fatty acid (NEFA), tumor necrosis factor-α (TNFα), and interleukin-1β (IL-1β) concentrations. Data were analyzed by repeated measures ANOVA using SAS Enterprise Guide v. 7.1. No changes in plasma parameters were indicated between periods for unsupplemented horses (P > 0.1) during Period2, excepting glucose, which was greater during Period2 (P = 0.018). Supplemented horses had lesser concentrations of TNFα (P = 0.016) and lactate (P = 0.058) during Period2 than during Period1. During Period2, supplemented horses experienced a smaller percent increase in post exercise muscle soreness (P = 0.031). DigestaWell® NRG supplementation may benefit unconditioned horses undergoing moderate intensity exercise through reducing lactate production and inflammation.
Full-text available
Article
It has been hypothesized that a major objective of morphological adaptation in limb-bone diaphyses is the achievement of uniform regional safety factors between discrete cortical locations (e.g. between cranial and caudal cortices at mid-diaphysis). This hypothesis has been tested, and appears to be supported in the diaphyses of ovine and equine radii. The present study more rigorously examined this question using the equine third metacarpal (MC3), which has had functionally generated intracortical strains estimated by a sophisticated finite element model. Mechanical properties of multiple mid-diaphyseal specimens were evaluated in both tension and compression, allowing for testing of habitually tensed or compressed regions in their respective habitual loading mode (`strain-mode-specific' loading). Elastic modulus, and yield and ultimate strength and strain, were correlated with in vivo strain data from a previously published finite element model. Mechanical tests revealed minor variations in elastic modulus, and yield and ultimate strength in both tension and compression loading, while physiological strains varied significantly between the cortices. Contrary to the hypothesis of uniform safety factors, the MC3 has a broad range of tension (caudo-medial, 4.0; cranio-lateral, 37.7) and compression (caudo-medial, 5.7; cranio-lateral, 68.9) safety factors.
Full-text available
Article
To quantify the extent of muscle alteration during prolonged exercise, the release rate of creatine kinase (CK) from striated muscle was measured in six horses during a rest period (6 h) and during three exercise tests (15, 30, and 60 km) at a constant speed of 200 m/min. CK clearance was measured after intravenous bolus administration (150 U/kg) of a CK solution obtained from horse muscle. The CK steady-state volume of distribution was 0.059 +/- 0.0215 l/kg, the terminal half-life was 123 +/- 28 min, and the plasma clearance was 0.36 +/- 0.10 ml.kg-1 x min-1. After an intramuscular CK administration, the CK systemic availability was 74.1 +/- 21.2% and the half time of absorption was 9.4 +/- 5.7 h, indicating a slow process for CK transit through the lymphatic system. The CK release rate was only significantly increased during the 60-km exercise test. The increase of CK plasma activity was observed after a delay of approximately 5 h and peaked after the end of the race; the estimated CK release rate was 9.92 +/- 2.62 U.kg-1 x h-1 over a mean duration period of 65.8 +/- 15.8 h. With the CK activity of horse striated muscle taken into account, a 60-km race released a quantity of CK corresponding to an equivalent of 18.8 +/- 4.3 g striated muscle. It is concluded that the equivalent amount of damaged muscle may be considered as negligible for a 60-km test and that only very high plasma CK activity levels (at least higher than 10,000 U/l) may provide some evidence of a myolysis.
Full-text available
Article
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.
Full-text available
Article
Although all patients undergoing total joint arthroplasty are subjected to similar risk factors that predispose to thromboembolism, only a subset of patients develop this complication. The objective of this study was to determine whether a specific genetic profile is associated with a higher risk of developing a postoperative thromboembolic complication. Specifically, we examined if the Factor V Leiden (FVL) mutation or the deletion polymorphism of the angiotensin-converting enzyme (ACE) gene increased a patient's risk for postoperative thromboembolic events. The FVL mutation has been associated with an increased risk of idiopathic thromboembolism and the deletion polymorphism of the ACE gene has been associated with increased vascular tone, attenuated fibrinolysis and increased platelet aggregation. The presence of these genetic profiles was determined for 38 patients who had a postoperative symptomatic pulmonary embolus or proximal deep venous thrombosis and 241 control patients without thrombosis using molecular biological techniques. The Factor V Leiden mutation was present in none of the 38 experimental patients and in 3% or 8 of the 241 controls (p = 0.26). Similarly there was no difference detected in the distribution of polymorphisms for the ACE gene with the deletion-deletion genotype present in 36% or 13 of the 38 experimental patients and in 31% or 74 of the 241 controls (p = 0.32). Our results suggest that neither of these potentially hypercoaguable states are associated with an increased risk of symptomatic thromboembolic events following total hip or knee arthroplasty in patients receiving pharmacological thromboprophylaxis.
Full-text available
Article
Evidence-based medicine (EBM) is being embraced by an increasing number of practitioners and advocates of complementary and alternative medicine (CAM). A significant constituency within CAM, however, appears to have substantive doubts about EBM and some are expressly hostile. Many of the arguments raised against EBM within the CAM community are based on a caricature radically at odds with established, accepted and published principles of EBM practice. Contrary to what has sometimes been argued, EBM is not cookbook medicine that ignores individual needs. Neither does EBM mandate that only proven therapies should be used. Before EBM, decisions on health care tended to be based on tradition, power and influence. Such modes usually act to the disadvantage of marginal groups. By placing CAM on an equal footing with conventional medicine - what matters for both is evidence of effectiveness - EBM provides an opportunity for CAM to find an appropriate and just place in health care.
Full-text available
Article
Post-exercise muscle soreness is a dull, aching sensation that follows unaccustomed muscular exertion. Primarily on the basis of previous laboratory-based research on eccentric exercise, soreness is usually said to follow an inverted U-shaped curve over time, peaking 24 - 48 hours after exercise. As such, it is often described as "delayed-onset" muscle soreness. In a study of long-distance runners, soreness seemed to peak immediately and then reduce gradually over time. The study is a secondary analysis of clinical trial data that aims to determine whether the time course of soreness following a natural exercise, long-distance running, is different from that following a laboratory-based exercise, bench-stepping. This is a reanalysis of data from three previous clinical trials. The trials included 400 runners taking part in long-distance races and 82 untrained volunteers performing a bench-stepping test. Subjects completed a Likert scale of muscle soreness every morning and evening for the five days following their exercise. Interaction between trial and time is highly significant, suggesting a different time course of soreness following running and bench-stepping. 45% of subjects in the bench-stepping trial experienced peak soreness at the third or fourth follow-up (approximately 36 - 48 hours after exercise) compared to only 14% of those in the running trial. The difference between groups is robust to multivariate analysis incorporating possible confounding variables. Soreness in runners following long-distance running follows a different time course to that in untrained individuals undertaking bench-stepping. Research on exercise taking place in the laboratory context does not necessarily generalize to exercise undertaken by trained athletes when engaged in their chosen sport.
Full-text available
Article
This study was aimed to analyze the loss of muscle explosive force in the early phase of eccentric exercise-induced damage, and its possible relationships with muscle soreness and blood creatine kinase (CK) levels. Squat jump (SJ) and countermovement jump (CMJ) heights decreased in response to an eccentric exercise (120 eccentric actions of the knee extensors), with reductions that persisted at least for 24 h. The SJ/CMJ ratio was not significantly modified. Blood CK levels changed significantly over time and CK activity was significantly higher at 6 and at 24 h when compared to values obtained immediately after the eccentric exercise. Muscle soreness perceived at 6 h was slightly higher than that experienced just after finalizing the exercise and reached a clearly upper value at 24 h. A highly significant relationship between SJ and CMJ height loss was observed. CK activity at 24 h was significantly related to the SJ height loss at 6 h and to both the SJ height loss and the CMJ height loss immediately after the exercise. In summary, eccentric exercise induced a reduction in the explosive force generating capacity that affected in a similar way the pure concentric jump (SJ) and the jump eliciting the stretch-shortening cycle (CMJ). Results obtained suggest that CK activity is a better predictor of explosive force reduction than soreness, at least when values close to the peak are used.
Article
To answer the question whether an experienced rider or a dead weight influences a horse's workload and/or its locomotion, 9 well trained Dutch Warmblood horses, fully accustomed to treadmill exercise, underwent a submaximal standardised treadmill exercise test under 3 different conditions: unloaded, mounted by an experienced rider of 90 kg and loaded with 90 kg of lead. Heart rate was monitored continuously and plasma lactate concentrations were determined in venous jugular blood samples immediately before and 2 and 10 min after exercise. Temporal and angular stride variables were measured in fore- and hindlimbs at the walk (1.7 m/s), trot (4.0 m/s) and canter (7.0 m/s) with a modified CODA-3 computerised kinematic analysis system. Peak heart rates during exercise, and recovery heart rates thereafter were significantly lower in the unloaded horses compared to the mounted and lead-loaded horses. Plasma lactate concentrations immediately and 10 min after exercise were also significantly lower in the unloaded horses than in the mounted and lead-loaded horses. No differences were found in heart rate and plasma lactate concentration between the mounted and lead-loaded horses. Relative stance duration increased comparing the unloaded to the mounted and the lead-loaded horses (P<0.05). Small, but significant, differences were also observed in the fetlock extension and the maximal fetlock range of motion; both increased with loading. In conclusion, an experienced rider and a dead weight influence both workload and locomotion in exercising horses. Minimal differences were found between dead lead weight and a rider.
Article
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 f 0.52 d s) and with a rider (3.49 f 0.46 d 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 in-hand 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.
Article
The behaviour of cortical bone under load is strain rate-dependent, i.e. it is dependent on the rate at which the load is applied. This is particularly relevant in the galloping horse since the strain rates experienced by the bone are far in excess of those recorded for any other species. In this study the effect of strain rates between 0.0001 and 1 sec-1 on the mechanical properties of equine cortical bone were assessed. Initially, increasing strain rates resulted in increased mechanical properties. Beyond a critical value, however, further increases in strain rate resulted in lower strain to failure and energy absorbing capacity. This critical rate occurred around 0.1 sec-1 which is within the in vivo range for a galloping racehorse. Analysis of the stress-strain curves revealed a transition in the type of deformation at this point from pseudo-ductile to brittle. Bones undergoing brittle deformation are more likely to fail under load, leading to catastrophic fracture and destruction of the animal.
Article
The purpose of this study was to compare the analgesic effect of pulsating ultrasound treatment and placebo on delayed onset of muscle soreness produced by an eccentric exercise bout. In addition, the effect of pulsed ultrasound on muscular performance following an eccentric exercise bout was studied. Eighteen untrained subjects were randomly assigned to: 1) ultrasound (A) [N = 6] over the areas of concentrated muscle soreness, i.e. proximal vastus lateralis and distal vastus medialis; 2) placebo ultrasound (B) [N = 6]; and 3) no therapeutic intervention (C) [N = 6]. Baseline data were recorded for maximum isometric knee extension contraction (MVC), maximum knee extension torque (MT), knee extension work (W), and soreness perception (SP). All values were subsequently reassessed 24 and 48 hours after intense muscular activity. Immediately following the 24 hour reassessment the A group received ultrasound treatment, the B group received placebo ultrasound, while the C group received no treatment. Percent deviation from baseline of SP, MVC, MT and W were significantly less for A than B and C (p less than 0.05) at 48 hours post muscle soreness bout. These data indicate that pulsed ultrasound accelerates restoration of normal muscle performance, and thus is effective in decreasing delayed onset of muscle soreness. The mechanism for decreasing soreness perception in the muscle is unknown, but may be related to decreasing intramuscular pressure and/or decreasing the inflammatory response.
Article
The perception of muscle soreness is probably due to the activation of free nerve endings around muscle fibers. These nerve endings serve as receptors of noxious stimuli associated with muscle damage. Modulation of soreness may take place at the peripheral receptor sites or at a central or spinal level. This multilevel modulation may explain the large intersubject variation in the perception of muscle soreness. The type of exercise that produces the greatest degree of soreness is eccentric exercise, although isometric exercise may also result in soreness. Eccentric exercise has been shown to produce muscle cellular damage and decrements in motor performance as well. Although training is considered to prevent muscle soreness, even trained individuals will become sore following a novel or unaccustomed exercise bout. Thus, training is specific to the type of exercise performed. Our laboratories have shown that the performance of a single exercise bout will have an effect on a subsequent similar bout given up to 6 weeks later. Thus, when a second bout of downhill running was given to subjects 6 weeks after the first bout, with no intervening exercise, less soreness developed, and muscle damage was estimated to be reduced. The explanation for this long-lasting prophylactic or "training effect" is currently under investigation in our laboratories.
Article
The application of transmission ultrasonics to the equine cannon holds promise as a method of monitoring metacarpal and metatarsal development, quality and integrity under a variety of experimental and field conditions. The validity of relating the velocities of sound pulses transmitted through the cannon to the mechanical breaking strengths of these bones was tested in two studies. Breaking strengths calculated from the sound velocities through sections of the metacarpal bones from 14 yearling ponies and 12 yearling horses were highly correlated with the mechanical breaking strengths of those sections (r = .907 and .927, respectively; P less than .01). Sound velocities through the cannons of the horses before sacrifice ranged from 2,453 to 3,130 m/s and were correlated with their mechanically determined breaking strengths (193 to 262 X 10(6) N/M2; r = .673; P less than .01). The correlation coefficient increased to .912 when the sound velocities were adjusted for the sound-delaying effects of the overlying soft tissues. In a third study, 13 horses were weaned at 2 to 4 mo of age and were fed diets providing either 100 or 130% of National Research Council (NRC) energy and protein recommendations. Metacarpal and metatarsal development was monitored monthly for 15 mo via transmission ultrasonics. Sound velocities, breaking strengths calculated from velocities adjusted for estimated soft tissue cover, measured bone mediolateral diameters and cannon diameters minus estimated soft tissue increased as quadratic functions of chronologic age (r greater than .840; P less than .0001). None of these variables was significantly affected by diet, leg or sex. These studies have demonstrated that the use of transmission ultrasonics to estimate and monitor metacarpal and metatarsal breaking strengths in the live horse is reliable, reproducible, simple, accurate and valid. They also suggest that NRC energy and protein recommendations meet the requirements for maximum bone growth and development in well-managed young equines.
Article
The flexural tests on 37 whole equine metacarpus bones are described and the results are given in terms of fundamental material properties as a function of age. The moduli of elasticity, rupture, and failure increase then decrease with increasing age. The rupture and failure deformations decrease with age. The stiffness and fragility indices increase with age. Averaging the data for all ages, the modulus of rupture was 35 ksi, the deflection at rupture was 0.22 inches, and the modulus of elasticity was 1.7 × 10 psi. The flexural rupture strength is about twice the uniaxial compression strength and about five times greater than the torsional strength for whole bone tests. The moduli of elasticity are about the same for flexure and uniaxial compression, and about five times greater than the torsional modulus of rigidity for whole equine bone.
Article
Longitudinal stresses acting in the cranial and caudal cortices of the radius and the dorsal and palmar cortices of the metacarpus in the horse were determined using two independent methods simultaneously. One approach involved the use of rosette strain gauges to record in vivo bone strain; the other involved filming the position of the horse's forelimb as it passed over a force plate. Agreement between the two analyses was better for the radius than for the metacarpus. Both methods showed the radius to be loaded primarily in sagittal bending, acting to place the caudal cortex in compression and the cranial cortex in tension. At each gait the magnitude of peak stress in each cortex based on the film/force analysis was 1.5-2 times higher than that determined from the bone strain recordings. In the metacarpus, the magnitude of stress in each cortex calculated from the film/force method was 2-3 times greater at each gait than that shown by the bone strain recordings. However, whereas the film/force analysis indicated that the metacarpus was loaded in sagittal bending (acting to place the palmar cortex in compression and the dorsal cortex in tension), the bone strain recordings showed the metacarpus to be loaded primarily in axial compression at each gait. Because the film/force method depends on an accurate measure of limb segment orientation relative to the direction of ground reaction force, comparatively small errors in calculations of bending moments may lead to a significant difference in the level and distribution of stress determined to act in the bone's cortices. The discrepancy in metacarpal loading obtained by the two methods may be explained in part by the simplicity of the biomechanical model which, for instance, neglected the force exerted by the sesamoids on the distal end of the metacarpus. The records of stress determined from the in vivo bone strain recordings showed that each bone was subjected to a consistent loading regime despite changes of gait. Such a consistent strain distribution should allow these bones to maximize economy in the use of tissue required to support the dynamic loads applied. Peak stresses measured from the bone strain recordings in the radius during locomotion at constant speed (-40.8 +/- 4.1 MN m-2) were significantly larger than those in the metacarpus (-25.1 +/- 2.8 MN m-2), regardless of speed and gait. During acceleration and deceleration, however, peak stress rose dramatically in the metacarpus (-40.6 +/- 3.4 MN m-2) but remained constant in the radius (-37.8 +/- 5.8 MN m-2).(ABSTRACT TRUNCATED AT 400 WORDS)
Article
Three-hundred and sixty horses, primarily of Arabian breeding, age 5-22 years and body conditions scores 1.5-5.5 (on 1 to 9 scale as described by Henneke 1985), participated in one of two 160 km endurance races over the same course in August 1995 and July 1996. Condition score, cannon bone circumference, combined rider and tack weight, heart girth and body length were measured 11-18 h prior to the start of the event and bodyweight estimated according to the formula by Carroll and Huntington (1988). A rider weight ratio was calculated as rider weight divided by horse bodyweight. Rider weight and rider weight ratio had no effect on overall completion rates among all horses (P > 0.05). Among horses successfully completing the course, rider weight and rider weight ratio had no effect on finish time or placing (P > 0.05). Among horses who were eliminated, rider weight and rider weight ratio had no effect on miles completed before failure (P > 0.05). Condition scores had a significant effect on completion rate (P < 0.001). Distance successfully completed increased 31.81 km (19.88 miles) for each incremental increase of 1 in condition score (P < 0.001). Within the group of unsuccessful horses, there was a significant difference in condition score between horses who failed due to metabolic and nonmetabolic factors (P < 0.001). It was concluded that condition score is a more important factor in endurance performance than has been previously believed, and that condition score is a more important factor than is the weight of the rider, or the rider weight in relation to the weight of the mount.
Article
It has been hypothesized that a major objective of morphological adaptation in limb-bone diaphyses is the achievement of uniform regional safety factors between discrete cortical locations (e.g. between cranial and caudal cortices at mid-diaphysis). This hypothesis has been tested, and appears to be supported in the diaphyses of ovine and equine radii. The present study more rigorously examined this question using the equine third metacarpal (MC3), which has had functionally generated intracortical strains estimated by a sophisticated finite element model. Mechanical properties of multiple mid-diaphyseal specimens were evaluated in both tension and compression, allowing for testing of habitually tensed or compressed regions in their respective habitual loading mode ("strain-mode-specific" loading). Elastic modulus, and yield and ultimate strength and strain, were correlated with in vivo strain data from a previously published finite element model. Mechanical tests revealed minor variations in elastic modulus, and yield and ultimate strength in both tension and compression loading, while physiological strains varied significantly between the cortices. Contrary to the hypothesis of uniform safety factors, the MC3 has a broad range of tension (caudo-medial, 4.0; cranio-lateral, 37.7) and compression (caudo-medial, 5.7; cranio-lateral, 68.9) safety factors.
Article
Quantitative ultrasound is in widespread clinical use for assessment of bone quality at peripheral skeletal sites, but has not yet been applied to those sites in the axial skeleton, such as the spine and hip, where osteoporotic fractures are common. Ultrasound measurements were made in 11 cadaveric vertebrae and relationships with bone mineral density and failure load were investigated. An ultrasonic imaging system was used to measure speed of sound, broadband ultrasonic attenuation, and attenuation at a single frequency, through the vertebral body in the sagittal plane. Ultrasonic measurements were averaged over a region of interest centrally within the vertebral body, and were calculated with and without normalization for bone size. Vertebral bone mineral density was measured in antero-posterior and lateral projections using dual energy X-ray absorptiometry. Compressive mechanical testing was performed to determine vertebral failure load. Bone mineral density correlated with failure load (r=0.74-0.78, all P<0.01), and with quantitative ultrasound (r=0.63-0.82, P=0.038-0.004), in line with previous studies. Of the ultrasonic measurements, those parameters not normalized for bone size gave the highest correlations with failure load, ranging from r=0.71 (P=0.021) for speed of sound to r=0.93 (P<0.001) for attenuation. When ultrasonic measurements were normalized for bone size, the correlations with both failure load and bone mineral density were lower. These results confirm the feasibility of vertebral quantitative ultrasound in vitro, and indicate that ultrasound does provide information on both bone mineral density and failure load. The predictive performance of ultrasonic measurements for failure load was comparable to or greater than that of bone mineral density, suggesting that ultrasound has the potential to be at least as useful as mineral density in the assessment of vertebral bone. Normalizing ultrasonic measurements for bone size reduced the strength of correlations because both bone mineral density and bone strength reflect bone size to a certain extent.
Pathophysiology of exercise induced diseases of musculoskeletal system of the equine athlete
  • Lindholm
Lindholm A. Pathophysiology of exercise induced diseases of musculoskeletal system of the equine athlete. In: Gillespie JR, Robinson NE, eds. Equine exercise physiology 2. Davis, CA: ICEEP Publications; 1987:711-727.
Maximum oxygen uptake in racehorses: changes with training state and prediction from submaximal cardiorespiratory measurements
  • Evans
Evans DL, Rose RJ. Maximum oxygen uptake in racehorses: changes with training state and prediction from submaximal cardiorespiratory measurements. In: Gillespie JR, Robinson NE, eds. Equine exercise physiology 2. Davis, CA: ICEEP Publications; 1987:52-67.
b RR (breaths/min) Pre-exercise 17.0 AE 2
Pre-exercise 35.0 AE 1.3 a 35.5 AE 4.7 a 37.6 AE 2.4 a 40.6 AE 1.6 a Post-exercise 77.0 AE 8.8 a 71.4 AE 5.1 a 91.1 AE 8.1 b 99.1 AE 3.6 b RR (breaths/min) Pre-exercise 17.0 AE 2.1 a 18.7 AE 1.8 a 18.5 AE 1.2 a 21.0 AE 1.1 a Post-exercise 45.0 AE 4.4 a 55.4 AE 6.1 a 70.0 AE 2.0 b 78.0 AE 1.4 b T rec (8F) Pre-exercise 99.1 AE 0.1 a 99.2 AE 0.2 a 99.2 AE 0.3 a 99.0 AE 0.4 a Post-exercise 101.0 AE 0.4 a 100.7 AE 0.2 a 102.6 AE 0.2 b 102.3 AE 0.1 b REFERENCES 1. Garlinghouse SE, Burill MJ. Relationship of body condition score to completion rate during 160 km endurance races. Equine Vet J 1999;30(Suppl):591-595.
The influence of body measurements and condition score on performance results during the 1998 Tevis Cup
  • Se Garlinghouse
  • Re Bray
  • Ea Cogger
  • Sj Wickler
Garlinghouse SE, Bray RE, Cogger EA, Wickler SJ. The influence of body measurements and condition score on performance results during the 1998 Tevis Cup. Proceedings 16th Equine Nutrition and Physiology Society Symposium; 1999:398-402.
The influence of body measurements and condition score on performance results during the 1998 Tevis Cup
  • Garlinghouse