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.
Buyck C, Zani DD, Robert M, Gustafsson K.Computed tomography (CT) is increasingly recognized as superior to conventional imaging methods for diagnosing osteomyelitis in foals. However, comprehensive studies in this area are limited. This study aims to report on clinical cases of osteomyelitis in foals, establishing a relationship between CT findings and survival outcomes. Additionally, it compares CT imaging with conventional methods such as radiography and ultrasound. We hypothesized that CT variables would more accurately predict survival than other clinical factors and provide more detailed information about osteomyelitis lesions....
Buyck C, Zani DD, Robert M, Gustafsson K.Computed tomography (CT) is increasingly recognized as superior to conventional imaging methods for diagnosing osteomyelitis in foals. However, comprehensive studies in this area are limited. This study aims to report on clinical cases of osteomyelitis in foals, establishing a relationship between CT findings and survival outcomes. Additionally, it compares CT imaging with conventional methods such as radiography and ultrasound. We hypothesized that CT variables would more accurately predict survival than other clinical factors and provide more detailed information about osteomyelitis lesions....
Costa GL, Tabbì M, Bruschetta G, Spadola F, Leonardi F, Bruno F, Iannelli NM, Licata P, Macrì F, Passino ES, Macrì D, Interlandi C.The study aimed to evaluate the analgesic efficacy of tapentadol in horses, by determining plasma serotonin concentration and adrenocortical response, as biomarkers of pain stress in chronic joint disorders. Thirty-six horses (20 females and 16 males) were divided into three groups of 12 subjects each: group A, osteoarthritis (OA), grade 3-4 lameness; group B, OA, grade 5 lameness; and group C, no OA, no lameness, were enrolled. The orthopedic examination included flexion tests, and radiological and ultrasound examinations. The degree of lameness has been estimated from 0 to 5 according to the...
Cervantes-Sevilla JR, Ramírez-Cervera M, Guzman-Ruvalcaba MJ.Traumatic hemothorax is a serious condition requiring immediate intervention. We present a case of a 48-year-old male professional jockey who suffered traumatic hemothorax, bilateral pulmonary contusions, and multiple rib fractures after being stomped by a horse. Management included intercostal drainage placement, costal fixation from the 5th to the 10th rib, and intensive care unit admission. Postoperative complications included, acute kidney injury, rhabdomyolysis, and severe acute respiratory distress syndrome. This case highlights the importance of a multidisciplinary approach in managing ...
DeBoer M, Rieck T, Johnson L, Redenius H, Martinson K.Horses have become more intensively managed, including the use of hay nets to increase intake time and reduce hay waste, but their impact on health is not well known. The objectives were to compare changes in subluxations, range of motion, and the pain-pressure threshold in the axial skeleton of horses fed hay with (NET) or without (CON) hay nets. In September 2021, 13 adult horses were blocked by bodyweight (BW) and randomly assigned to the NET or CON treatments for one year. After one year, horses switched treatments and the trial concluded in September 2023. Horses were housed in dry lots w...
Blatter M, Chapman HS, Heinzel-Gutenbrunner M, von Plato G, Rijkenhuizen A.Desmotomy of the accessory ligament of the superficial digital flexor tendon (AL-SDFT) has been described for the treatment of superficial digital flexor tendon (SDFT) tendinopathy in Thoroughbred and Standardbred racehorses, and in event horses. To our knowledge, the outcome of this procedure has not been described in a population of warmblood horses. Objective: To report on the outcome of treatment of SDFT tendinopathy in warmblood horses using tenoscopic desmotomy of the main part of the AL-SDFT. Methods: Prospective observational case series. Methods: All 62 horses included in the case ser...
Kneipp MLA, Sousa LN, Cota LO, Malacarne BD, Winter IC, Santana CH, Santos RL, Xavier ABS, Faleiros RR, Carvalho AM.Coxofemoral dysplasia is a condition characterized by the abnormal development and flattening of the femoral head and deformities in the acetabulum, leading to joint instability. Although described in various animal species, it is uncommon and rarely reported in horses. This article presents a case of incapacitating coxofemoral dysplasia diagnosed in a four-month-old foal Mangalarga Marchador, which exhibited lameness in the hind limbs, thoracolumbar kyphosis, gluteal muscle atrophy, and pronounced sensitivity during pelvic limb flexion. The clinical diagnosis indicative of bilateral coxofemor...
Crecan CM, Ciulu-Angelescu V, Morar IA, Lupșan AF, Tripon MA, Tripon MA, Bungărdean D, Daradics Z, Peștean CP.Global technological advancements have shifted equine lameness diagnostics from purely subjective assessment toward more objective, quantitative methods. Traditional gait evaluations are increasingly being supplemented by innovative technologies to enhance diagnostic accuracy. Unassigned: This study aimed to determine if traditional gait assessment could be effectively complemented by quantitative measurements using an affordable, self-constructed device, the Lameness Detector 0.1, which incorporates inertial motion sensors. Unassigned: A total of 42 adult sport horses diagnosed with hindleg l...
Valberg SJ, Porter A.Muscle biopsy is often required to provide a definitive diagnosis for neuromuscular disorders and can be performed using open surgical or percutaneous needle biopsy techniques. Fresh samples that are subsequently frozen in the laboratory are preferred by laboratories engaged in research, whereas formalin-fixed muscle is processed by diagnostic laboratories with specialized tinctorial and immunohistochemical techniques. Interpretation by an experienced histopathologist, combined with the signalment, history, and clinical input, is essential for establishing a diagnosis. This article outlines be...
Guest DJ, Birch HL, Thorpe CT.The suspensory ligament (SL) is a key component of the elaborate and highly adapted suspensory apparatus in the horse. In addition to contributing to stabilisation of the metacarpophalangeal joint, the SL has a spring like function to reduce the energetic cost of locomotion. Although the SL is highly prone to injury in horses of all ages and competing in a wide range of disciplines, knowledge regarding fundamental structure-function relationships in the SL is lacking, particularly compared with other injury-prone tendinous structures such as the superficial digital flexor tendon. In this revie...
Loder RT, Walker AL, Blakemore LC.Fractures often occur due to equestrian activities with injury patterns varying by age. The purpose of this study was to investigate in detail fracture patterns and associated demographics in children due to equine activities. Methods: The US National Electronic Injury Surveillance System was queried for all injuries with the consumer product code 1239 (horseback riding) from 2000 to 2023. Those <16 years old with fractures were extracted. Statistical analyses were performed with SUDAAN 11.0.01™ software to obtain national estimates. Results: There were an estimated 101,677 patients with a f...
Seabaugh K, Rao S, Koenig JB, Pezzanite L, Dow S, Koch TG, Russell KA, Mehrpouyan S, Alizadeh AH, Goodrich LR.Synovitis is present before and during osteoarthritis in horses and can result in performance-limiting lameness. Twenty-four horses with lameness localized to the metacarpo-/metatarsophalangeal joint or a single joint of the carpus were enrolled in this study. We evaluated the response of intra-articular injection with 10 million activated (aMSC) or non-activated (naMSC) allogeneic equine umbilical cord blood-derived mesenchymal stromal cells (MSCs). Subjective and objective lameness was assessed on Days 0, 1, 21, and 42. The treatment injection was randomly assigned and performed following th...
Bogossian PM, Nattala U, Wong ASM, Morrice-West AV, Zhang GZ, Rana P, Whitton RC, Hitchens PL.Decreasing speed and stride length over successive races have been shown to be associated with musculoskeletal injury (MSI) in racehorses, demonstrating the potential for early detection of MSI through longitudinal monitoring of changes in stride characteristics. A machine learning (ML) approach for early detection of MSI, enforced rest, and retirement events using this same horse-level, race-level, and stride characteristic data across all race sectionals was investigated. A CatBoost model using features from the two races prior to an event had the highest classification performance (sensitiv...
Skelton G, Acutt E, Stefanovski D, van Eps A.Traditional radiographic measurements of distal phalanx (Pd) displacement based on the outer hoof wall are not useful for diagnosis of acute laminitis. Objective: We hypothesised that the distance between the inner hoof wall and Pd ('lamellar lucent zone'; LLZ) measured on lateromedial digital radiographs would be increased in horses with acute and subacute laminitis compared with healthy horses. Methods: Retrospective cohort study and in vivo experimental study. Methods: Forelimb radiographs from 32 healthy and 18 laminitic mixed-breed horses were analysed retrospectively. Laminitis was defin...
Elashry MI, Speer J, De Marco I, Klymiuk MC, Wenisch S, Arnhold S.Osteoarthritis (OA) is a chronic progressive degenerative joint disease that affects a significant portion of the equine population and humans worldwide. Current treatment options for equine OA are limited and incompletely curative. Horses provide an excellent large-animal model for studying human OA. Recent advances in the field of regenerative medicine have led to the exploration of extracellular vesicles (EVs)-cargoes of microRNA, proteins, lipids, and nucleic acids-to evaluate their diagnostic value in terms of disease progression and severity, as well as a potential cell-free therapeutic ...
Neville EK, Neville CC, Hicks H.The size, strength, and unpredictability of horses, makes any interaction a potential situation for minor to severe injury. Despite this, horses continue to be popular for work and recreational activities. There have been five recent Australian publications that have examined various aspects of horse-related trauma, but none have been conducted in regional New South Wales (NSW). This study aims to report on the pattern of horse-related trauma that met the Institute of Trauma Injury Management's (ITIM) Trauma Registry criteria for people who presented to the emergency department at a regional N...
Taddey CM, Roecken M, Kreling KM, Cruz AM.Reliable lameness thresholds for vertical head displacement for trotting on a circular path and on different surfaces have yet to be defined. Withers movement in lame horses could help improve the diagnostic accuracy of sensor technology. Objective: To define head movement lameness threshold ranges and describe the relationship between head and withers movement during trotting under different circumstances in sound and forelimb lame horses. Methods: Retrospective analysis of clinical data and comparison with control group. Methods: Fifty-five sound and thirty-four naturally lame horses were tr...
Uellendahl A, Schramel JP, Tichy A, Peham C.The aim of this study was to determine whether horses exhibiting unilateral hindlimb lameness unload (rest) the lame limb more than the contralateral limb. The resting/unloading of the hindlimbs and the time spent lying down were measured using accelerometers. Ten non-lame horses and 20 lame horses were recruited for participation and monitored for 11 h overnight with accelerometers (MSR145, sampling rate: 1 Hz, and measuring range: ±15 g) attached to the lateral metatarsal and metacarpal regions of each limb. Metatarsal and metacarpal orientation were used to determine whether the limb was u...
Hagenbach M, Bierau J, Cruz AM, Koch C, Manso-Díaz G, Büttner K, Staszyk C, Röcken M.In the diagnostics of orthopedic diseases in the horse, diagnostic imaging often plays a decisive role. Cone beam computed tomography (CBCT) imaging is used in both human and small animal medicine and becoming increasingly popular. To see whether CBCT imaging can be useful in the diagnosis of orthopedic diseases of the carpal region of the horse and to explore possible limitations we compared CBCT images with multidetector computed tomography (MDCT) images of the carpal region of equine cadaveric specimens. Unassigned: Twenty-eight forelimbs from fifteen horses, slaughtered for reasons unrelat...
Hagenbach M, Bierau J, Cruz AM, Koch C, Manso-Díaz G, Büttner K, Staszyk C, Röcken M.In the diagnostics of orthopedic diseases in the horse, diagnostic imaging often plays a decisive role. Cone beam computed tomography (CBCT) imaging is used in both human and small animal medicine and becoming increasingly popular. To see whether CBCT imaging can be useful in the diagnosis of orthopedic diseases of the carpal region of the horse and to explore possible limitations we compared CBCT images with multidetector computed tomography (MDCT) images of the carpal region of equine cadaveric specimens. Unassigned: Twenty-eight forelimbs from fifteen horses, slaughtered for reasons unrelat...
Willette JA, Tsoi M, Frobish D, VanderBroek AR.The objectives of the study were to describe a standing percutaneous adhesion induction model in the digital flexor tendon sheath (DFTS) of horses and to evaluate the effect of intrathecal administration of the angiotensin-converting enzyme (ACE) inhibitor enalapril on tendon healing and adhesion formation. Methods: Randomized, blinded, controlled experimental study. Methods: Eight healthy horses. Methods: A collagenase-induced adhesion model was implemented in the deep digital flexor tendon (DDFT) of both forelimbs under standing ultrasonographic guidance. Daily intrathecal injections of 5 ...
Riley JW, Chance LM, Barshick MR, Johnson SE.Hyaluronic acid (HA), a glycosaminoglycan found in joint synovial fluid, is administered to horses as an anti-inflammatory with lubrication properties. This experiment examined the effects of HA administered before and shortly after an exercise test on metacarpophalangeal (MCP; fetlock) and tibiotarsal (hock) joint range of motion (ROM). Horses were injected intravenously (IV) with placebo (4 mL, saline) or HA (4 mL, 40 mg) 24 h before performing a standardized exercise test (SET) on a high-speed treadmill and again at 6-h post-SET. Passive fetlock flexion was measured at 4 and 24 h post-...
Gagliardi R, Koch DW, Loeser R, Schnabel LV.Osteoarthritis (OA) is a debilitating disease that impacts millions of individuals and has limited therapeutic options. A significant hindrance to therapeutic discovery is the lack of in vitro OA models that translate reliably to in vivo preclinical animal models. An alternative to traditional inflammatory cytokine models is the matrikine stimulation model, in which fragments of matrix proteins naturally found in OA tissues and synovial fluid, are used to stimulate cells of the joint. The objective of this study was to determine if matrikine stimulation of equine synovial fibroblasts and chond...
Süß F, Guth S, Müller-Ehrenberg H, Röcken M, Staszyk C.The masticatory muscles of the horse are arranged in an asymmetrical pattern. Four individual muscles on the medial side of the mandible are opposed by one muscle (M. masseter) on the lateral side. However, recent studies on various herbivorous mammals indicate that the masseter muscle features a complex stratigraphic structure that might account for a functional diversity resembling an arrangement of several individual muscles. The functional consideration of the multidirectional equine masticatory movements leads to a similar hypothesis. In order to elucidate the detailed anatomy of the equi...
Spoormakers TJP, Veraa S, Graat EAM, van Weeren PR, Brommer H.Data on equine thoracic pathology hardly exist in breeds other than Thoroughbreds. Objective: To describe pathological changes of the osseous thoracic vertebral column in Warmblood horses, Shetland ponies and Konik horses, and to compare prevalence and severity. Methods: Descriptive post-mortem study. Methods: Computed tomography was used to examine the thoracic vertebral column of 34 Warmblood horses, 28 Shetland ponies, and 18 Konik horses. Osteoarthritis (OA), periarticular osteolysis, osseous cyst-like lesions and fragments of articular processes (APJs), costovertebral and costotransverse ...
Van Mol B, Janssens S, Oosterlinck M, Pille F, Buys N.Equine osteochondrosis and osteochondral fragments in the fetlock joint are linked to various environmental and genetic risk factors. To assess the scope of the literature linking these risk factors to the development of these osteochondral disorders, while identifying knowledge gaps and challenges to guide future research, a scoping review was performed. This article constitutes the second part of this scoping review and focuses on genetic factors, with the first part addressing environmental factors. To identify potentially relevant papers, online bibliographical databases PubMed and Web of ...
Ogden NKE, Winderickx K, Stack JD.Computed tomography (CT) of the axial skeleton is increasing across many equine hospitals. CT of the pelvis and caudal spine in a large group of clinical cases has not been reported previously. Objective: To describe the pathological lesions identified in the caudal spine/pelvis in horses and ponies undergoing CT spine of this region. Methods: A retrospective case series. Methods: Horses with CT imaging of the caudal spine/pelvis were included. Horses aged under 6 months and those with CT examinations performed post-mortem were excluded. Results: Fifty-six horses met the inclusion criteria. ...
Irwin-Huston JM, Bourebaba L, Bourebaba N, Tomal A, Marycz K.Musculoskeletal injuries and chronic degenerative diseases pose significant challenges in equine health, impacting performance and overall well-being. Sex Hormone-Binding Globulin (SHBG) is a glycoprotein determining the bioavailability of sex hormones in the bloodstream, and exerting critical metabolic functions, thus impacting the homeostasis of many tissues including the bone. Unassigned: In this study, we investigated the potential role of SHBG in promoting osteogenesis and its underlying mechanisms in a model of equine adipose-derived stromal cells (ASCs). An SHBG-knocked down model has b...
Eren G, López-Albors O, Guilabert Segura R, Jordan Montesinos J, Latorre R.The accessory ligament of the deep digital flexor tendon (AL-DDFT) plays a crucial role in the stay apparatus of the horse. This study aimed to investigate the anatomical relationship between the AL-DDFT, the superficial digital flexor tendon (SDFT), and other structures in the metacarpal region. Sixteen distal forelimbs from eight horses, aged 1 to 6 years, were evaluated through macroscopic, microscopic, and morphometric analyses, utilizing detailed dissection, E12 plastinated sections, and histological analysis. During lateral dissection, a connection was observed between the AL-DDFT and th...
Ogden NKE, Winderickx K, Bennell A, Stack JD.Cross-sectional imaging improves the diagnostic accuracy of complex anatomical regions. Computed tomography (CT) of the pelvis and caudal spine in a large group of live horses and ponies has not been previously reported. Objective: To describe the procedure for acquiring CT images of horses' caudal spine/pelvis under general anaesthesia (GA) and to detail the image quality, artefacts and anatomical variations in this region. Methods: Retrospective case series. Methods: Horses with CT of the caudal spine/pelvis were included. Horses under 6 months and CT examination performed post-mortem were...
Eivers SS, McGivney BA, Gu J, MacHugh DE, Katz LM, Hill EW.Peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) has emerged as a critical control factor in skeletal muscle adaptation to exercise, acting via transcriptional control of genes responsible for angiogenesis, fatty acid oxidation, oxidative phosphorylation, mitochondrial biogenesis and muscle fibre type composition. In a previous study, we demonstrated a significant increase in mRNA expression for the gene encoding PGC-1α (PPARGC1A) in Thoroughbred horse skeletal muscle following a single bout of endurance exercise. In this study, we investigated mRNA expression changes i...
Estberg L, Stover SM, Gardner IA, Johnson BJ, Case JT, Ardans A, Read DH, Anderson ML, Barr BC, Daft BM, Kinde H, Moore J, Stoltz J, Woods LW.To characterize and contrast data from Thoroughbreds that incurred a fatal musculoskeletal injury (FMI; injury resulting in death or euthanasia) during racing or training and data from all California race entrants during a 9-month period in 1991. Methods: Case-control study. Methods: Thoroughbreds that incurred a FMI during racing or training at a California race-meet and all California race entrants from January through June and October through December 1991. Methods: Age and sex were compared with chi 2 and Fisher's exact tests among horses fatally injured while racing and training. A log-li...
Egenvall A, Tranquille CA, Lönnell AC, Bitschnau C, Oomen A, Hernlund E, Montavon S, Franko MA, Murray RC, Weishaupt MA, Weeren vR, Roepstorff L.Orthopaedic, or other, injuries in sports medicine can be quantified using the 'days-lost to training' concept. Both the training regimen and the surface used in training and racing can affect the health of racehorses. Our aim was to associate 'days-lost to training' in elite-level show-jumpers to horse characteristics, training and management strategies, and the time spent working on various training and competition surfaces. We designed a longitudinal study of professional riders in four European countries. Data were recorded using training diaries. Reasons for days-lost were classified into...
Patterson-Kane JC, Firth EC.Despite the high incidence of superficial digital flexor tendon (SDFT) injury in racehorses, the pathobiology of the condition is not clearly defined. The SDFT improves locomotor efficiency by storing elastic energy, but as a result it has low mechanical safety margins. As with the Achilles tendon in humans, rupture during athletic activity often follows accumulation of exercise and age-induced degenerative change that is not repaired by tenocytes. There is limited understanding of tenocyte biology and pathology, including responses to high mechanical strains and core temperatures during exerc...
Sun TC, Riggs CM, Cogger N, Wright J, Al-Alawneh JI.Reports of fractures in racehorses have predominantly focused on catastrophic injuries, and there are limited data identifying the location and incidence of fractures that did not result in a fatal outcome. Objective: To describe the nature and the incidence of noncatastrophic and catastrophic fractures in Thoroughbreds racing at the Hong Kong Jockey Club (HKJC) over seven racing seasons. Methods: Retrospective cohort study. Methods: Data of fractures sustained in horses while racing and of race characteristics were extracted from the HKJC Veterinary Management Information System (VMIS) and Ra...
Barr ED, Pinchbeck GL, Clegg PD, Boyde A, Riggs CM.Thoroughbred racehorses are commonly affected by subchondral bone injury, but the exact prevalence and the distribution of palmar/plantar osteochondral disease (POD) lesions are unknown. The relationship between pathologies has not been elucidated, although it is widely accepted that POD is a manifestation of traumatic overload arthrosis. Objective: There is an association between grade of POD and other pathologies affecting the third metacarpal and metatarsal (MC/MTIII) condyles (wear lines, cartilage loss, marginal remodelling, dorsal impact injuries and linear fissures). Objective: To evalu...
Simon EL, Gaughan EM, Epp T, Spire M.To determine the amount of time required for surface temperatures of thoracic and pelvic limbs in horses to return to pre-exercise temperatures after high-speed treadmill exercise, as detected via infrared thermographic imaging. Methods: Prospective study. Methods: 6 Thoroughbreds. Methods: All horses had been trained on and conditioned to use of a high-speed treadmill. Baseline thermographic images were obtained 3 days prior to exercise (baseline). Horses were exercised on a treadmill at a walk for 5 minutes, a slow trot (3 m/s) for 5 minutes, a trot (5 to 6 m/s) for 5 minutes, and a slow gal...
Townsend HG, Leach DH.The anatomical features of 21 equine thoracolumbar spines, obtained from horses with clinically normal backs, were examined and the results compared with recent data on the mobility of the joint complexes of the horse's spine. The thoracolumbar spine can be divided into four regions based upon the morphology of the joint complexes: the first thoracic intervertebral joint (T1-2), the cranial and mid thoracic region (T2-T16), the caudal thoracic and lumbar region (T16-L6) and the lumbosacral joint. The mobility of the intervertebral joints in each of these regions can be related to their morphol...
Martin RB, Lau ST, Mathews PV, Gibson VA, Stover SM.We studied birefringence as an indicator of collagen fiber orientation in the diaphysis of the equine third metacarpal bone. We had previously shown that tissue from the lateral cortex of this bone is stronger monotonically, but less fatigue resistant, than tissue from the medial and dorsal regions. To learn whether collagen fiber orientation might play a role in this regional specialization, we tested three hypotheses using the same specimens: (1) collagen fiber orientation is regionally dependent; (2) remodeling changes collagen fiber orientation; (3) longitudinal collagen fibers correlate p...
Wennerstrand J, Johnston C, Roethlisberger-Holm K, Erichsen C, Eksell P, Drevemo S.Earlier studies have developed a clinical tool to evaluate objectively the function of the equine back. The ability to differentiate horses with back pain from asymptomatic, fully functioning horses using kinematic measures from this tool has not been evaluated. Objective: To compare the kinematics of the back at walk and trot in riding horses with back dysfunction to the same parameters in asymptomatic sport horses. Methods: The kinematics of the back in 12 horses with impaired performance and back pain were studied at walk and trot on a treadmill. Data were captured for 10 sees at 240 Hz. Ra...
Birn-Jeffery AV, Higham TE.Animals must continually respond dynamically as they move through complex environments, and slopes are a common terrain on which legged animals must move. Despite this, non-level locomotion remains poorly understood. In this study, we first review the literature on locomotor mechanics, metabolic cost, and kinematic strategies on slopes. Using existing literature we then performed scaling analyses of kinematic variables, including speed, duty factor, and stride-length across a range of body sizes from ants to horses. The studies that examined locomotion on inclines vastly outnumbered those focu...
Blumer R, Maurer-Gesek B, Gesslbauer B, Blumer M, Pechriggl E, Davis-López de Carrizosa MA, Horn AK, May PJ, Streicher J, de la Cruz RR, Pastor ÁM.To test whether palisade endings are a general feature of mammalian extraocular muscles (EOMs). Methods: Thirteen species, some frontal-eyed (human, monkey, cat, and ferret), and others lateral-eyed (pig, sheep, calf, horse, rabbit, rat, mouse, gerbil, and guinea pig) were analyzed. Palisade endings were labeled by using different combinations of immunofluorescence techniques. Three-dimensional reconstructions of immunolabeled palisade endings were done. Results: In all frontal-eyed species, palisade endings were a consistent feature in the rectus EOMs. Their total number was high and they exh...
Riemersa DJ, Schamhardt HC.A clamp designed for holding tendons in force/elongation studies is described. No slippage occurred when tensile forces up to 13,800 N were applied to horses digital flexor tendons fixed in this clamp.
Clegg PD.Tendon and ligament injuries continue to be one of the most frequent causes of orthopaedic injury and early retirement in the Thoroughbred racehorse. In the UK, the Horserace Betting Levy Board has invested considerable research funding in the last decade in order to investigate aspects of tendon epidemiology, biology and therapy, in order to decrease both the welfare and economic consequence of such injuries. This review summarises key aspects of this research effort and identifies specific research directions for the future.
Klein DJ, McKeever KH, Mirek ET, Anthony TG.The athletic horse, despite being over 50% muscle mass, remains understudied with regard to the effects of exercise and training on skeletal muscle metabolism. To begin to address this knowledge gap, we employed an untargeted metabolomics approach to characterize the exercise-induced and fitness-related changes in the skeletal muscle of eight unconditioned Standardbred horses (four male, four female) before and after a 12-week training period. Before training, unconditioned horses showed a high degree of individual variation in the skeletal muscle metabolome, resulting in very few differences ...
Innes JF, Clegg P.Examples of naturally occurring musculoskeletal disorders are extremely common in veterinary species and provide a valuable comparative research resource, which can provide compelling comparative data on the aetiopathogenesis and treatment of many common human musculoskeletal diseases. In particular, orthopaedic diseases are a common morbidity in both dogs and horses. In this review, we give an overview of the common musculoskeletal diseases encountered in these species: for instance, tendon and ligament injuries, arthropathies and stress fractures, as well as an insight into the basic biology...
Maliye S, Voute LC, Marshall JF.This study aimed to quantify the compensatory response to naturally-occurring forelimb lameness on load redistribution. Data from lameness investigations using an inertial sensor based system to monitor the response to forelimb diagnostic anaesthesia were reviewed. Horses with primary forelimb lameness were grouped for analysis as (1) all horses combined (n= 28), (2) forelimb-only lameness (n= 8/28), (3) forelimb-contralateral hindlimb lameness (n= 14/28), (4) forelimb-ipsilateral hindlimb lameness (n= 6/28). The effect of diagnostic anaesthesia on measures of head and pelvic movement ...
Anderson JR, Phelan MM, Foddy L, Clegg PD, Peffers MJ.Osteoarthritis is an age-related degenerative musculoskeletal disease characterized by loss of articular cartilage, synovitis, and subchondral bone sclerosis. Osteoarthritis pathogenesis is yet to be fully elucidated with no osteoarthritis-specific biomarkers in clinical use. equine cartilage explants ( = 5) were incubated in tumor necrosis factor-α (TNF-α)/interleukin-1β (IL-1β)-supplemented culture media for 8 days, with the media removed and replaced at 2, 5, and 8 days. Acetonitrile metabolite extractions of 8 day cartilage explants and media samples at all time points underwent one-d...
White A, Estrada M, Walker K, Wisnia P, Filgueira G, Valdés F, Araneda O, Behn C, Martínez R.During exercise, the oxygen consumption and the production of free radicals increase and can lead to oxidative stress with a deleterious effect on cellular structures involved in physical activity. To evaluate the oxidative stress produced by exercise and the role of ascorbate as an antioxidant, venous blood samples were obtained from 44 thoroughbred racehorses, before and after a 1000+/-200-m race at maximum velocity. Fourteen of these horses were treated intravenously with 5 g of ascorbate before running. Antioxidant capacity (PAOC), endogenous and exogenous ascorbate concentration, total an...
Schuurman SO, Kersten W, Weijs WA.Horses spend much of their life standing, and they are believed to be able to keep their limbs straight without muscular effort. We tested the hypothesis that the stifle (knee) and hock (tarsal) joints could be stabilized merely with the help of a passive lock mechanism whereby the patella is secured behind a hook, formed by the medial femoral trochlea. In anaesthetized animals and isolated limbs the stifle and hock flex readily under compression. In isolated limbs this collapse was prevented by a small force applied to the patella, mimicking the action of the vastus medialis muscle. In vivo, ...
Hobbs SJ, Clayton HM.The aims of this study were to measure ground reaction forces (GRFs) of concurrently loaded limbs and to evaluate spatial relationships between the centre of pressure (COP) and centre of mass (COM) in trotting horses. Kinematic (120Hz) and GRF data were collected at trot from three trials of eight horses using four force plates (960 Hz). Forelimb and hind limb GRFs were measured, COP was calculated from the resultant vertical GRF vector and COM was calculated by summation of weighted segmental COMs. Peak total vertical force (19.3 ± 1.3N/kg at 45.1 ± 2.3% diagonal stance) coincided with zero...
O'Brien C, Marr N, Thorpe C.The forelimb superficial digital flexor tendon (SDFT) is an energy-storing tendon that is highly susceptible to injury during activities such as galloping and jumping, such that it is one of the most commonly reported causes of lameness in the performance horse. This review outlines the biomechanical and biothermal effects of strain on the SDFT and how these contribute to the accumulation of microdamage. The effect of age-related alterations on strain response and subsequent injury risk is also considered. Given that tendon is a slowly healing and poorly regenerative tissue, prompt detection o...
Lyle CH, Blissitt KJ, Kennedy RN, Mc Gorum BC, Newton JR, Parkin TD, Stirk A, Boden LA.Sudden death adversely affects racehorse welfare, jockey safety and the public perception of horseracing. Objective: To describe the risk of racing-associated sudden death in Thoroughbred racehorses in the UK from 2000 to 2007, to identify whether there were risk factors uniquely associated with sudden death and to improve the understanding of the pathogenesis of racing-associated sudden death by identification of risk factors for such cases. Methods: A sudden death was defined as an acute collapse and death, in an apparently healthy Thoroughbred racehorse, during or immediately after racing, ...
Chiaradia E, Avellini L, Rueca F, Spaterna A, Porciello F, Antonioni MT, Gaiti A.Since it has been suggested that lipid peroxidation following free radical overproduction may be one of the causes of physical exercise-induced myopathies and hemolysis in horses, we looked for the possible relationships between these phenomena and muscle fiber damage. We use a homogeneous group of Maremmana stallions which, after a 3-month training period, underwent a series of physical exercises of increasing intensity. We determined the contents of malondialdehyde (MDA), one of the main lipid peroxidation end-products, and glutathione the substrate of one of the most important free radical ...
Sullivan KA, Hill AE, Haussler KK.Common methods used to treat back problems in horses need to be assessed objectively. Objective: To measure spinal mechanical nociceptive thresholds (MNTs) and evaluate the effects of chiropractic, massage and phenylbutazone, compared with active and inactive control groups. Methods: Baseline MNTs at 7 sites within the thoracolumbar and sacral regions were measured in 38 healthy mature horses exhibiting no clinical signs of lumbar pain. Horses were assigned to one of 3 treatment groups: instrument-assisted chiropractic treatment, therapeutic massage and phenylbutazone; or 2 control groups: rid...
Dutto DJ, Hoyt DF, Clayton HM, Cogger EA, Wickler SJ.The net work of the limbs during constant speed over level ground should be zero. However, the partitioning of negative and positive work between the fore- and hindlimbs of a quadruped is not likely to be equal because the forelimb produces a net braking force while the hindlimb produces a net propulsive force. It was hypothesized that the forelimb would do net negative work while the hindlimb did net positive work during trotting in the horse. Because vertical and horizontal impulses remain unchanged across speeds it was hypothesized that net work of both limbs would be independent of speed. ...
Canè V, Botti P, Soana S.The influence of pulsed low-frequency electromagnetic fields (PEMFs) on bone formation was investigated in studies of the healing process of transcortical holes, bored at the diaphyseal region of metacarpal bones of six adult horses, exposed for 30 days to PEMFs (28 G peak amplitude, 1.3 ms rise time, and 75 Hz repetition rate). A pair of Helmholtz coils, continuously powered by a pulse generator, was applied for 30 days to the left metacarpal bone, through which two holes, of equal diameter and depth, had been bored at the diaphyseal region. Two equal holes, bored at the same level in the rig...
Peham C, Kotschwar AB, Borkenhagen B, Kuhnke S, Molsner J, Baltacis A.The aim of the study was to compare the stability of the rider as well as the forces acting on a horse's back with different seating positions at the trot (sitting trot, rising trot and two-point seat). The same experienced rider was mounted on 10 sound horses trotting on a treadmill. The kinetic data were recorded with an electronic pressure mat, placed under a well-fitting dressage saddle with no saddle pad. The rider used three different seating positions, each for 20 s. Right forelimb motion was used to synchronise the pressure data with the stride cycles. To determine the rider's stabilit...
Côté GP, Smillie LB.Whereas skeletal muscle tropomyosin binds strongly to muscle F-actin in a buffer containing 30 mM KCl and 1-2 mM free Mg2+, equine platelet tropomyosin only binds stoichiometrically (1 tropomyosin molecule per 6 actin monomers) at higher Mg2+ concentrations (7-8 mM free Mg2+). At low free Mg2+ concentrations (1.5 mM) the binding of the platelet protein is only marginally increased by raising the KCl concentration to an optimal value (0.10-0.20 M). This weaker binding can be attributed to the relatively poor head-to-tail polymerization of platelet tropomyosin and its fewer actin-binding sites. ...
Spiesz EM, Thorpe CT, Thurner PJ, Screen HRC.Structure-function relationships in tendons are directly influenced by the arrangement of collagen fibres. However, the details of such arrangements in functionally distinct tendons remain obscure. This study demonstrates the use of quantitative polarised light microscopy (qPLM) to identify structural differences in two major tendon compartments at the mesoscale: fascicles and interfascicular matrix (IFM). It contrasts functionally distinct positional and energy storing tendons, and considers changes with age. Of particular note, the technique facilitates the analysis of crimp parameters, in w...
