The musculoskeletal system in horses encompasses the bones, muscles, tendons, ligaments, and joints that facilitate movement and provide structural support. This system is essential for locomotion, athletic performance, and overall health in equine species. The equine skeleton consists of approximately 205 bones, which are connected by joints and supported by a network of muscles and connective tissues. Tendons connect muscles to bones, while ligaments link bones to other bones, contributing to joint stability. The musculoskeletal system is subject to various conditions, including injuries, degenerative diseases, and developmental disorders, which can impact a horse's mobility and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, pathology, and treatment of musculoskeletal conditions in horses.
Burger D, Vidondo B, Gerber V, Deillon D, Müller A, Scheidegger M, Käser R, Ramseyer A.Fatigue and related injuries to the musculoskeletal system are among the most frequent reasons for the withdrawal of high-level eventing horses from the sport. The safety of both horse and rider is very important, and early detection of fatigue is crucial. Objective: To investigate elite eventing horses in competitive events focusing on biomechanical, cardiovascular and metabolic variables across the cross-country test and to identify their potential associations with fatigue. Methods: Prospective observational exploratory field study. Methods: Observations on 54 cross-country tests of 33 hors...
Koch DW, Schnabel LV.Tendon injuries are common in both veterinary and human clinical patients and result in morbidity, pain, and lost athletic performance. Consequently, utilizing naturally occurring injuries in veterinary patients as a comparative model could inform the development of novel therapies and increase translation for the treatment of human tendon injuries. Mesenchymal stem cells (MSCs) have shown considerable efficacy for the treatment of experimental and clinical superficial digital flexor tendon injury in the horse; however, the reinjury rate following treatment can remain high and MSC efficacy in ...
Salbaş E, Karahan AY.Newly created systems called hippotherapy simulators (HS) mimic the primitive movements of a live horse. As they are new systems, research examining their usefulness has been well received. The aim of this study is to research the effects of HS on disease activity, quality of life and muscle strength in patients with ankylosing spondylitis (AS). Unassigned: In a prospective, assessor-blinded, block-randomized trial, 48 AS patients were randomly assigned in a 1:1 ratio to receive either HS or conventional home (CH) exercise therapy. All Participants received 48 sessions, that is 4 sessions a we...
Watts AE.Mesenchymal stem cells (MSCs) are used as a regenerative therapy in horses for musculoskeletal injury since the late 1990s and in some regions are standard of care for certain injuries. Yet, there is no Food and Drug Administration-approved MSC therapeutic in the United States for horses. In humans, lack of regulatory approval in the United States has been caused by failure of late-phase clinical trials to demonstrate consistent efficacy, perhaps because of nonuniformity of MSC preparation and application techniques. This article discusses clinical evidence for musculoskeletal applications of ...
Ebisuda Y, Mukai K, Takahashi Y, Yoshida T, Kawano A, Matsuhashi T, Miyata H, Kuwahara M, Ohmura H.Heat acclimatization or acclimation training in horses is practiced to reduce physiological strain and improve exercise performance in the heat, which can involve metabolic improvement in skeletal muscle. However, there is limited information concerning the acute signaling responses of equine skeletal muscle after exercise in a hot environment. The purpose of this study was to investigate the hypothesis that exercise in hot conditions induces greater changes in heat shock proteins and mitochondrial-related signaling in equine skeletal muscle compared with exercise in cool conditions. Fifteen t...
Xing J, Xie L, Qi X, Liu G, Akhtar MF, Li X, Bou G, Bai D, Zhao Y, Dugarjaviin M, Zhang X.The proliferation and differentiation of skeletal muscle satellite cells (SCs) are necessary for the development of mature skeletal muscle. Leucine (Leu) is both an essential amino acid (EAA) and a branched-chain amino acid (BCAA), which has attracted worldwide attention due to its ability to repair and become new fibers. We separated the equine SCs into the control group (CON) and the Leu-supplemented group (LEU), which the cells were cultured in Leu-deprived and Leu-supplemented media respectively. We combined the transcriptome (RNA-Seq) and quantitative proteome (TMT) profiling analyses on ...
Vidal Moreno de Vega C, Lemmens D, de Meeûs d'Argenteuil C, Boshuizen B, de Maré L, Leybaert L, Goethals K, de Oliveira JE, Hosotani G, Deforce D....Important changes in glucose transporter (GLUT) expression should be expected if the glucose influx plays a pivotal role in fuelling or connecting metabolic pathways that are upregulated in response to exercise. The aim was to assess GLUT4, 8, and 12 dynamics in response to training and acute exercise. Sixteen untrained Standardbred mares (3-4 year) performed an incremental SET at the start and end of 8 weeks harness training. M. pectoralis (PM) and M. vastus lateralis (VL) muscle biopsies were taken before and after each SET, allowing for comparing rest and acute samples in untrained (UT) ...
Palomino Lago E, Jelbert ER, Baird A, Lam PY, Guest DJ.Persistent inflammation is associated with the poor regeneration of musculoskeletal tissues. Embryonic stem cells (ESCs) have an attenuated response to inflammatory cytokines, but there are mixed reports on the response of induced pluripotent stem cells (iPSCs) to inflammation. Horses provide a relevant large animal model for studying musculoskeletal tissue diseases and the testing of novel therapies. The aim of this study was to determine if equine iPSCs are responsive to the inflammatory cytokines IL-1β, TNFα and IFN-γ in their undifferentiated state, or following differentiation into ten...
Horan K, Price H, Day P, Mackechnie-Guire R, Pfau T.Injuries to racehorses and their jockeys are not limited to the racetrack and high-speed work. To optimise racehorse-jockey dyads' health, well-being, and safety, it is important to understand their kinematics under the various exercise conditions they are exposed to. This includes trot work on roads, turf and artificial surfaces when accessing gallop tracks and warming up. This study quantified the forelimb hoof kinematics of racehorses trotting over tarmac, turf and artificial surfaces as their jockey adopted rising and two-point seat positions. A convenience sample of six horses was recruit...
Bennet ED, Parkin TDH.Racehorse training and racing schedules in many parts of the United States and Canada were interrupted or otherwise reduced during the first three to six months of 2020. This was an indirect consequence of mitigations to prevent the spread of the pandemic virus COVID-19. Data from the Equine Injury Database, a census-level survey of all race starts made in the USA and Canada, were used to analyse the incidence of fatalities in 2009-2022 among three age cohorts of racehorses within each year. There was a statistically significant increase in the incidence of musculoskeletal fatalities among 2-y...
Sander J, Terhardt M, Janzen N, Renaud B, Kruse CJ, François AC, Wouters CP, Boemer F, Votion DM.Equine atypical myopathy is caused by hypoglycin A (HGA) and methylenecyclopropylglycine (MCPrG), the known protoxins of sycamore maple (Acer pseudoplatanus). Various tissues from five atypical myopathy cases were analyzed but only HGA was found. Whether deamination of MCPrG has already occurred in the intestine as the first stage of metabolization has not been investigated. Activation of the protoxins to methylenecyclopropylacetyl (MCPA)-CoA and methylenecyclopropylformyl (MCPF)-CoA, respectively, occurred mainly in the skeletal muscles, as evidenced by very high concentrations of MCPA-carnit...
Nocera I, Sorvillo B, Sgorbini M, Aliboni B, Citi S.Few studies have established the normal radiographic anatomical development of the donkey foal and, to date, no data are available for mules. Our aim was thus to evaluate the radiographic development of the fore digit and carpal joint in the mule foal from 0 to 3 months of age. Ten forelimbs of five healthy full-term mule foals were included. Radiographs of the fore digit lateromedial and dorsopalmar and the carpus dorsopalmar were performed weekly for the first month of age, and bi-monthly during the following two months. Fore digit growth plate closure times, morphological, angular, and line...
Horne CR, Tufts S.Continual advancements in diagnostic imaging have allowed for more accurate and complete diagnoses of injuries in the performance horse. The use of several different imaging tools has further allowed the equine sports medicine clinician to more carefully direct treatment options, monitor response to therapy and guide rehabilitation recommendations. The advancements in diagnostic imaging and novel treatment options have led to the improvement in the overall prognosis of many injuries that affect the horse and their performance. The purpose of this section is to review the advancements made in d...
Shojaee A.Tendons are dense connective tissues that play an important role in the biomechanical function of the musculoskeletal system. The mechanical forces have been implicated in every aspect of tendon biology. Tendon injuries are frequently occurring and their response to treatments is often unsatisfactory. A better understanding of tendon biomechanics and mechanobiology can help develop treatment options to improve clinical outcomes. Recently, tendon tissue engineering has gained more attention as an alternative treatment due to its potential to overcome the limitations of current treatments. This ...
Etemadi F, Tabatabaei Naeini A, Aminlari M.Minerals play vital roles in physiologic processes. Calcium, phosphorus and magnesium are common minerals. Secretion, absorption and homeostasis of these minerals are affected by associations between the active vitamin D and parathyroid hormone (PTH). The aim of this study was to assess concentrations of vitamin D, PTH and minerals, such as calcium, phosphorus and magnesium in horse sera, as well as associations of these values with lameness in horses. In the references, the reasons for lameness can be deficiency and imbalance of minerals, and clinical observations also confirm this and there ...
Zaha C, Schuszler L, Dascalu R, Nistor P, Florea T, Rujescu C, Sicoe B, Igna C.The field of veterinary medicine lacks information on equine thermal hoof printing, and few data on the same subject are available in dogs. In human medicine, thermography is used to detect heat emitted by the foot when it comes in contact with a flat surface to detect the abnormalities of the foot balance. The hypothesis states that the thermal pattern of the hoof print in Warmblood horses is detectable and it does not vary among the four limbs in leisure and cross-country Warmblood horses in terms of mean temperature of the hoof print surface. A pilot study was conducted to investigate the a...
St George L, Spoormakers TJP, Roy SH, Hobbs SJ, Clayton HM, Richards J, Serra Bragança FM.The reliability of surface electromyography (sEMG) has not been adequately demonstrated in the equine literature and is an essential consideration as a methodology for application in clinical gait analysis. This observational study investigated within-session, intra-subject (stride-to-stride) and inter-subject reliability, and between-session reliability of normalised sEMG activity profiles, from triceps brachii (triceps), latissimus dorsi (latissimus), longissimus dorsi (longissimus), biceps femoris (biceps), superficial gluteal (gluteal) and semitendinosus muscles in n = 8 clinically non-lam...
Knych HK, McKemie DS, Kass PH, Stanley SD, Blea J.Ketoprofen is an anti-inflammatory drug that is commonly administered to racehorses for the alleviation of musculoskeletal pain and inflammation. This study represents a comprehensive examination of the metabolism (in vivo and in vitro), pharmacokinetics and ex vivo pharmacodynamics, of ketoprofen in horses. The in vitro metabolism as well as specific enzymes responsible for metabolism was determined by incubating liver microsomes and recombinant CYP450 and UGT enzymes with ketoprofen. For the in vivo portion, 15 horses were administered a single intravenous dose of 2.2-mg/kg ketoprofen. Blood...
Crecan CM, Peștean CP.Objective gait analysis provides valuable information about the locomotion characteristics of sound and lame horses. Due to their high accuracy and sensitivity, inertial measurement units (IMUs) have gained popularity over objective measurement techniques such as force plates and optical motion capture (OMC) systems. IMUs are wearable sensors that measure acceleration forces and angular velocities, providing the possibility of a non-invasive and continuous monitoring of horse gait during walk, trot, or canter during field conditions. The present narrative review aimed to describe the inertial ...
Fortier LA.Bone marrow concentrate is generated by centrifugation of bone marrow aspirate. It contains mesenchymal stromal cells, anabolic chemokines/cytokines, and supraphysiological concentrations of interleukin-1 receptor antagonist protein (IL-1RA). It is an effective treatment for osteoarthritis or desmitis, or as an adjunct in surgery to enhance bone or cartilage repair.
Deride C, Chihuailaf R, Arnés V, Morán G, Uberti B.Microminerals are necessary for all bodily functions. In animal species, selenium (Se), copper (Cu) and zinc (Zn) all form part of antioxidant enzymes. Micromineral deficiencies, particularly Se, are well recognized in large animal species in Chile. Glutathion peroxidase (GPx) is a widely used biomarker for Se nutritional status and to diagnose Se deficiency in horses. Superoxide dismutase (SOD) is a Cu and Zn-dependant antioxidant enzyme, although it is not commonly used as a proxy for the nutritional status of these minerals. Ceruloplasmin (CP) is used as a biomarker of Cu nutritional status...
McCoy AM, Scolman KN.The aim of this study was to identify the radiographic prevalence of periarticular osteophytes of the distal tarsus in nonlame yearling Standardbred horses, and to evaluate its potential impact on race performance. Methods: Cross-sectional cohort study. Methods: Client-owned yearling Standardbred horses (n = 416). Methods: Bilateral tarsal radiographs were available from all horses for review. Osteophytes were measured on radiographs using clinical visualization software and categorized by size. Racing records were obtained from the United States Trotting Association. Regression analysis w...
He H, Banks SA, Biedrzycki AH.The objective of this study was to provide an overarching description of the inter-subject variability of the equine femur and tibia morphology using statistical shape modeling. Fifteen femora and fourteen tibiae were used for building the femur and tibia statistical shape models, respectively. Geometric variations in each mode were explained by biometrics measured on ±3 standard deviation instances generated by the shape models. Approximately 95% of shape variations within the population were described by 6 and 3 modes in the femur and tibia shape models, respectively. In the femur shape mod...
Rohlf CM, Garcia TC, Marsh LJ, Acutt EV, le Jeune SS, Stover SM.During the stance phase of equine locomotion, ground reaction forces are exerted on the hoof, leading first to rapid deceleration ("braking") and later to acceleration ("propulsion") as the hoof leaves the ground. Excessive hoof deceleration has been identified as a risk factor for musculoskeletal injury and may be influenced by arena surface properties. Therefore, our objective was to evaluate the effect of arena surface type (dirt, synthetic) on hoof translation of the leading and trailing forelimbs during jump takeoff and landing. Solar hoof angle, displacement, velocity, and deceleration w...
Peat FJ, Kawcak CE, McIlwraith CW, Keenan DP, Berk JT, Mork DS.Subchondral lucencies (SCLs) in the distal aspect of the medial femoral condyle (MFC) of young Thoroughbred horses are a source of controversy on presale radiographs. There is limited scientific evidence regarding the risk of progression and impact on future racing performance. Objective: To (1) identify the prevalence of MFC SCLs on sales repository radiographs in yearling and 2-year-old Thoroughbreds; (2) identify any association between grade of MFC SCL and future racing performance and (3) monitor changes in MFC SCL grades between yearling and 2-year-old sales. Methods: Prospective cohort ...
Bou T, Ding W, Ren X, Liu H, Gong W, Jia Z, Zhang X, Dugarjaviin M, Bai D.Traditional Mongolian endurance training is an effective way to improve the athletic ability of the horse for endurance events and is widely used. This incorporates aerobic exercise and intermittent fasting and these altered physiologic conditions are associated with switches between muscle fibre types. Objective: To better understand the adaption of horse skeletal muscle to traditional Mongolian endurance training from muscle fibre characteristics and transcriptional levels and to explore possible molecular mechanisms associated with the endurance performance of horses. Methods: Before-after ...
Stevens KA, Caruso JC, Fallahi AKM, Patiño JM.Since initial reports suggesting primary tendon repair as possible and even desirable emerged in the 1960s, significant advancements in the understanding of flexor tendon anatomy, biology, mechanisms of response to injury, and methods of repair, have been made. Recent research highlights enhanced improvements in operative techniques and rehabilitative care that have made primary flexor tendon repair a preferred operative approach for lacerations and can successfully achieve a reliable flexor tendon repair site, optimizing digital motion. The formative goals of surgical treatment for lacerated ...
Śniegucka K, Soroko-Dubrovina M, Zielińska P, Dudek K, Žuffová K.Radial extracorporeal shock wave therapy (rESWT) is increasingly being used to treat musculoskeletal injuries in horses. The aim of this study was to assess the influence of rESWT on the skin surface temperature of the longissimus dorsi muscle in clinically healthy racing horses. A total of 24 thoroughbreds were divided into a study group (n = 12) and an rESWT-sham group (n = 12). The study group underwent rESWT, whereas the rESWT-sham group had rESWT without probe activation in the treated area. Both groups underwent thermographic examination before and just after rESWT to determine and compa...
Dyson S, Pollard D.The Ridden Horse Pain Ethogram (RHpE) was developed to facilitate the recognition of musculoskeletal pain. The aim of this study was to document changes in RHpE scores before and after diagnostic anaesthesia was performed to alleviate pain ± when the saddle was changed. One hundred and fifty horses underwent ridden exercise as part of an investigation of poor performance. The RHpE was applied before and after the interventions. Fifty-two (34.7%) horses exhibited a bilaterally symmetrical short step length and/or restricted hindlimb impulsion and engagement. Fifty-three (35.3%) horses had epis...
Mercer MA, Davis JL, McKenzie HC, Byron CR, Kelleher ME, Trager L, Cecere TE, Wilson KE, Council-Troche RM, Werre SR.Acetaminophen is used clinically in horses with musculoskeletal pain; however, no studies have been performed in horses with chronic lameness. Objective: To determine the pharmacokinetics, safety and efficacy of chronic dosing of acetaminophen in horses with naturally occurring chronic lameness. Methods: Longitudinal. Methods: Twelve adult horses with chronic lameness were treated with acetaminophen (30 mg/kg PO) every 12 h for 21 days. Plasma concentrations of acetaminophen were analysed on days 7 and 21 via LC-MS/MS and noncompartmental pharmacokinetic analysis. Lameness was evaluated ...
Stubbs NC, Hodges PW, Jeffcott LB, Cowin G, Hodgson DR, McGowan CM.Research in spinal biomechanics and functional anatomy has advanced back pain research in man. Yet, despite the performance limiting nature of back pain in horses, there are few data for the equine spine. Objective: To describe aspects of functional anatomy of the equine thoracolumbar and lumbosacral (LS) spine and potential effects on performance. Methods: The first study investigated variations in LS vertebral formula by post mortem examination of 120 horses. Midline vertebral transection was carried out on 65 Thoroughbred (TB), 24 Standardbred (SB) and 31 other breeds. The second study inve...
Kawcak CE, McIlwraith CW, Norrdin RW, Park RD, Steyn PS.To determine effects of treadmill exercise on subchondral bone of carpal and metacarpophalangeal joints of 2-year-old horses. Methods: 12 healthy 2-year-old horses. Methods: Horses were randomly assigned to the control (n = 6) or exercised (6) groups. Horses in the exercised group ran on a high-speed treadmill 5 d/wk for 6 months. Horses in the control group were hand walked for the same amount of time. Results of clinical, radiographic, nuclear scintigraphic, and computed tomographic examinations, and serum and synovial concentrations of biochemical markers of bone metabolism were compared be...
Chung MJ, Park S, Son JY, Lee JY, Yun HH, Lee EJ, Lee EM, Cho GJ, Lee S, Park HS, Jeong KS.In previous work, we established an equine induced pluripotent stem cell line (E-iPSCs) from equine adipose-derived stem cells (ASCs) using a lentiviral vector encoding four transcription factors: Oct4, Sox2, Klf4, and c-Myc. In the current study, we attempted to differentiate these established E-iPSCs into mesenchymal stem cells (MSCs) by serial passaging using MSC-defined media for stem cell expansion. Differentiation of the MSCs was confirmed by analyzing expression levels of the MSC surface markers CD44 and CD29, and the pluripotency markers Nanog and Oct4. Results indicated that the E-iPS...
Bodo G, Hangody L, Modis L, Hurtig M.To describe treatment of equine subchondral bone cysts (SBCs) by reconstruction of the articular surface with osteochondral grafts. Methods: Case series of horses with SBCs unresponsive to conservative therapy. Methods: Eleven horses (1-12 years). Methods: SBCs were identified in 4 locations: medial femoral condyle (5 horses), lateral femoral condyle (1), distal epiphysis of the metacarpus (4), or metatarsus (1). Osteochondral autograft transplantation (mosaic arthroplasty) was performed, taking grafts from the abaxial border of the medial femoral trochlea of the unaffected limb. Graft implant...
Moger CJ, Arkill KP, Barrett R, Bleuet P, Ellis RE, Green EM, Winlove CP.An investigation of collagen fiber reorientation, as well as fluid and matrix movement of equine articular cartilage and subchondral bone under compressive mechanical loads, was undertaken using small angle X-ray scattering measurements and optical microscopy. Small angle X-ray scattering measurements were made on healthy and diseased samples of equine articular cartilage and subchondral bone mounted in a mechanical testing apparatus on station ID18F of ESRF, Grenoble, together with fiber orientation analysis using polarized light and displacement measurements of the cartilage matrix and fluid...
Staiger EA, Al Abri MA, Pflug KM, Kalla SE, Ainsworth DM, Miller D, Raudsepp T, Sutter NB, Brooks SA.Conformation has long been a driving force in horse selection and breed creation as a predictor for performance. The Tennessee Walking Horse (TWH) ranges in size from 1.5 to 1.7 m and is often used as a trail, show, and pleasure horse. To investigate the contribution of genetics to body conformation in the TWH, we collected DNA samples, body measurements, and gait/training information from 282 individuals. We analyzed the 32 body measures with a principal component analysis. Principal component (PC)1 captured 28.5% of the trait variance, while PC2 comprised just 9.5% and PC3 6.4% of trait vari...
Taylor D, Kuiper JH.This paper addresses an anomaly which exists in the current literature regarding stress fractures. Analysis of the data on fatigue strength of bone samples in vitro would conclude that these fractures should never occur at the strain levels known to occur in vivo. This anomaly can be resolved by including in the analysis the effect of stressed volume, whereby larger volumes of material are expected to have worse fatigue properties. A Weibull analysis was used to predict the probability of failure, Pf; this was an upper-bound prediction because it did not include the effects of remodelling and ...
Reed SR, Jackson BF, Mc Ilwraith CW, Wright IM, Pilsworth R, Knapp S, Wood JL, Price JS, Verheyen KL.No large scale epidemiological studies have previously quantified the occurrence of carpal, metacarpo- and metatarsophalangeal (MCP/MTP) joint injuries in Thoroughbred racehorses. Objective: To develop an objective classification system for carpal and MCP/MTP joint injuries and estimate the incidence of these injuries in young Thoroughbreds in flat race training. Methods: In a prospective cohort study, data on daily exercise and veterinary-diagnosed carpal and MCP/MTP joint injuries were collected from Thoroughbreds monitored since starting training as yearlings, for up to 2 years. Cases were ...
Purohit RC, McCoy MD.To evaluate the use of thermography in equine medicine, a three-phase study was conducted. In the first phase, six horses were examined thermographically, before and after exercise, to determine a normal thermal pattern. In the second phase, nine horses with acute and chronic inflammatory processes were examined thermographically. In the third phase, thermography was used to evaluate the effectiveness of anti-inflammatory drugs on chemically induced inflammatory reactions. All normal horses tested had similar infrared emission patterns. There was a high degree of symmetry between right and lef...
Hobbs SJ, Richards J, Clayton HM.The diagonal limb support pattern at trot provides pitch and roll stability, but little is known about the control of moments about the centre of mass (COM) in horses. Correct COM location is critical in the calculation of pitching moments. The objectives were to determine the effect of COM location on pitching moments in trotting horses and explore how COM location could influence balance. Kinematic (120 Hz) and GRF (4 force plates, 960 Hz) data were collected at trot from three trials of eight horses. The position of the COM was determined from the weighted summation of the segmental COMs an...
Dyson S, Nagy A, Murray R.Eight sports horses with unilateral (4) or bilateral (3) forelimb or unilateral hindlimb (1) lameness had subtle radiologic abnormalities of the subchondral bone of the sagittal groove of the proximal phalanx associated with moderate or intense increased radiopharmaceutical uptake. High-field or low-field magnetic resonance (MR) imaging confirmed the presence of a fissure fracture or subchondral and trabecular bone trauma. Seven of eight lesions were located approximately midway between the dorsal and palmar cortices of the proximal phalanx; the eighth was sited more dorsally. Two horses under...
Hiller LP, Stover SM, Gibson VA, Gibeling JC, Prater CS, Hazelwood SJ, Yeh OC, Martin RB.An important concept in bone mechanics is that osteons influence mechanical properties in several ways, including contributing to toughness and fatigue strength by debonding from the interstitial matrix so as to "bridge" developing cracks. Observations of "pulled out" osteons on fracture surfaces are thought to be indicative of such behavior. We tested the hypothesis that osteon pullout varies with mode of loading (fatigue vs. monotonic), cortical region, elastic modulus, and fatigue life. Mid-diaphseal beams from the dorsal, medial, and lateral regions of the equine third metacarpal bone were...
Han H, McGivney BA, Allen L, Bai D, Corduff LR, Davaakhuu G, Davaasambuu J, Dorjgotov D, Hall TJ, Hemmings AJ, Holtby AR, Jambal T, Jargalsaikhan B....Selection for system-wide morphological, physiological, and metabolic adaptations has led to extreme athletic phenotypes among geographically diverse horse breeds. Here, we identify genes contributing to exercise adaptation in racehorses by applying genomics approaches for racing performance, an end-point athletic phenotype. Using an integrative genomics strategy to first combine population genomics results with skeletal muscle exercise and training transcriptomic data, followed by whole-genome resequencing of Asian horses, we identify protein-coding variants in genes of interest in galloping ...
Chand N, Eyre P.Histamine, 2-methylhistamine (a specific H1-agonist), 5-HT, PGF2alpha, SRS-A, bradykinin (BK) and carbachol contract bronchial and tracheal smooth muscles of the horse. Isoprenaline, PGE1, E2, dimaprit and 4-methylhistamine (last two = specific H2-agonists) relaxed airways which were partially contracted to carbachol. Mepyramine (a specific H1-antagonist) selectively antagonized contractions to histamine. In the presence of mepyramine, histamine caused relaxation of airways partially contracted to carbachol. Metiamide and burimamide (specific H2-antagonists) specifically antagonized or reverse...
Licka TF, Peham C, Frey A.To use electromyography (EMG) to measure physiologic activity of the longissimus dorsi muscles of horses during trotting on a treadmill. Methods: 15 adult horses (5 to 20 years old that weighed 450 to 700 kg) that did not have clinical signs of back pain. Methods: Data were recorded for each horse during trotting on a treadmill at speeds of 2.6 to 4.4 m/s. Surface electromyography was recorded bilaterally from the longissimus dorsi muscles at the levels of T12, T16, and L3. Results: In each motion cycle, 2 EMG maxima were found at the end of the diagonal stance phases. The EMG activity peaked ...
Menschik A.Mobility of the knee of the horse. The modification of medial and lateral femoral condyles by additional movement of the cruciate ligaments shown on the animal joint. Final rotation in the human knee-joint shapes the femoral condyles by additional movement of the cruciate ligaments. The roll-slide movement and final rotation lead to curving of the medial condyle of the femur in the transverse plane. The transition from the roll-slide into a tilting movement in the final phase of ultimate rotation reduces the power of the posterior ligamentous system of the knee-joint when there is a force tend...
Riggs CM, Boyde A.The present study addressed the question of whether training induces changes in bone density in the younger racehorse in regions relevant to the genesis of the common sagittal condylar fracture pattern and, if so, the nature of such alteration. Third metacarpal bones (McIII) were obtained from 12 experimental Thoroughbred, unbroken fillies, age 18.1-21.0 months at entry to the study. Six (Group E) undertook 19 weeks of progressive high intensity exercise on a high-speed treadmill at 3% incline. Six (Group C) walked 40 min each day. Clinical bone density was studied by Computed Tomography (CT) ...
Riemersma DJ, Schamhardt HC.The mechanical properties of the deep digital flexor tendon (DDFT), the superficial digital flexor tendon (SDFT) and the suspensory ligament (SL) of the hindlimb of the horse were studied in vitro. The tendons were observed at several morphologically distinct sites. The loaded tendon is homogeneously strained, in spite of large variations in cross-sectional area. Consequently the modulus of elasticity was inversely proportional to the corresponding cross-sectional area and ranged from 738 MPa (megaPascal, N mm-2) to 1398 MPa within the DDFT, from 1000 MPa to 1282 MPa within the SDFT and from 5...
Smith RKW, McIlwraith CW.Tendinopathy remains one of the most common musculoskeletal disorders affecting both human and equine athletes and presents a considerable therapeutic challenge. The following workshop report comes from the third Dorothy Havemeyer Symposium of Tendinopathy which provided a unique overview of our current understanding of both the basic science and the clinical challenges for diagnosing and treating tendinopathy in both species. Pathologically, tendon demonstrates alterations in both cellular, molecular, structural, and biomechanical features, leading to a spectrum of pathological endotypes. To ...
Gibson VA, Stover SM, Gibeling JC, Hazelwood SJ, Martin RB.We hypothesized that recently formed, incompletely mineralized, and thus, relatively deformable osteons in the equine third metacarpus enhance in vitro load-controlled fatigue life in two ways. Macroscopically, there is a compliance effect, because reduced tissue elastic modulus diminishes the stress required to reach a given strain. Microscopically, there is a cement line effect, in which new osteons and their cement lines more effectively serve as barriers to crack propagation. We studied 18 4 x 10 x 100 mm beams from the medial, lateral, and dorsal cortices of metacarpal bones from 6 thorou...
van Weeren PR, Barneveld A.Osteochondrosis (OC) in the horse has been defined as a disturbance in the process of endochondral ossification which is of multifactorial origin, becoming evident in a large number of joints. Exercise is one of the environmental factors that may influence the clinical manifestation of the disorder, but has never been thoroughly investigated. In this study we investigated the influence of exercise during the first 5 months on the development and distribution of OC lesions in foals of age 5 and 11 months. Forty-three foals, all from sires having OC in either the femoropatellar or tibiotarsal jo...
Stubbs NC, Riggs CM, Hodges PW, Jeffcott LB, Hodgson DR, Clayton HM, McGowan CM.The multifidus muscle plays a key role in spinal stabilisation. Multifidus atrophy ipsilateral to the side of osseous pathology has been demonstrated in man and pigs but has not been investigated in horses. Objective: To measure cross-sectional area (CSA) left/ right symmetry of equine multifidus ultrasonographically and relate asymmetry of multifidus with osseous spinal pathology in Thoroughbred racehorses. We hypothesised that ipsilateral multifidus CSA would be reduced when osseous pathological changes are present leading to left/right asymmetry in CSA. Methods: Twenty-two racehorses presen...
Drevemo S, Dalin G, Fredricson I, Hjertén G.The movements of the individual limbs of 30 clinically sound Standardbred trotters were studied using high-speed cinematography. At a speed of 12 metres per second (m/sec; 1:23.6 min/km) the mean stride length was 545 cm and the mean duration of the stride was 455 milliseconds (msecs). The stance phase in the forelimbs was 100 msecs and 177 msecs in the hindlimbs. This difference was due to a longer restraint period in the hindlimbs and resulted in slightly shorter swing phases for the hindlimbs. The variations in any particular horse for stride length and for the duration of stride, stance, s...
King MR, Haussler KK, Kawcak CE, McIlwraith CW, Reiser RF, Frisbie DD, Werpy NM.OBJECTIVE To evaluate the effects of exercise in an underwater treadmill (UWT) on forelimb biomechanics and articular histologic outcomes in horses with experimentally induced osteoarthritis of the middle carpal joint. ANIMALS 16 horses. PROCEDURES An osteochondral fragment was induced arthroscopically (day 0) in 1 middle carpal joint of each horse. Beginning on day 15, horses were assigned to exercise in a UWT or in the UWT without water (simulating controlled hand walking) at the same speed, frequency, and duration. Thoracic and pelvic limb ground reaction forces, thoracic limb kinematics, a...
Clayton HM, Lanovaz JL, Schamhardt HC, van Wessum R.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 exp...
Kawai M, Aida H, Hiraga A, Miyata H.Although satellite cells are well known as muscle stem cells capable of adding myonuclei during muscle repair and hypertrophy, the response of satellite cells in horse muscles to a run to exhaustion is still unknown. Objective: To investigate the time course of satellite cell activation in Thoroughbred horse muscle after running to exhaustion. We hypothesised that this type of intense exercise would induce satellite cell activation in skeletal muscle similar to a resistance exercise. Methods: Nine de-trained Thoroughbred horses (6 geldings and 3 mares) aged 3-6 years were studied. Biopsy sampl...
Tozaki T, Gamo S, Takasu M, Kikuchi M, Kakoi H, Hirota KI, Kusano K, Nagata SI.Doping control is an important and indispensable aspect of fair horse racing; genetic doping has been recently included to this. In this study, we aimed to develop a detection method of gene doping. A plasmid cloned with human erythropoietin gene (p.hEPO, 250 μg/head) was intramuscularly injected into a microminipig. Subsequently, p.hEPO was extracted from 1 mL of plasma and detected by droplet digital polymerase chain reaction. Results: The results confirmed that the maximum amount of plasmid was detected at 15 min after administration and the majority of the plasmid was degraded in the b...
Barrey E, Mucher E, Jeansoule N, Larcher T, Guigand L, Herszberg B, Chaffaux S, Guérin G, Mata X, Benech P, Canale M, Alibert O, Maltere P, Gidrol X.Several cases of myopathies have been observed in the horse Norman Cob breed. Muscle histology examinations revealed that some families suffer from a polysaccharide storage myopathy (PSSM). It is assumed that a gene expression signature related to PSSM should be observed at the transcriptional level because the glycogen storage disease could also be linked to other dysfunctions in gene regulation. Thus, the functional genomic approach could be conducted in order to provide new knowledge about the metabolic disorders related to PSSM. We propose exploring the PSSM muscle fiber metabolic disorder...
Martin AM, Elliott JA, Duffy P, Blake CM, Ben Attia S, Katz LM, Browne JA, Gath V, McGivney BA, Hill EW, Murphy BA.Circadian rhythms are innate 24-h cycles in behavioral and biochemical processes that permit physiological anticipation of daily environmental changes. Elucidating the relationship between activity rhythms and circadian patterns of gene expression may contribute to improved human and equine athletic performance. Six healthy, untrained mares were studied to determine whether locomotor activity behavior and skeletal muscle gene expression reflect endogenous circadian regulation. Activity was recorded for three consecutive 48-h periods: as a group at pasture (P), and individually stabled under a ...
Symes D, Ellis R.Rider asymmetry is anecdotally associated with underperformance and injury. In this study, rider axial rotation (AR) and shoulder angle displacement (SAD) were measured using video analysis, and leg length inequality (LLI) was measured to assess any correlation between LLI, AR and SAD. Two video cameras, recording transverse and sagittal views, simultaneously filmed each of 17 female riders in walk, trot, and left and right canter. The rider's shoulder angles relative to the cranial caudal line were measured at each limb impact for a complete stride cycle. All riders exhibited left AR and a gr...
