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.
Vosugh D, Nazem MN, Hooshmand AR.Among the different breeds of horses, Asil horses with a five thousand year history have played an important role in human life. This study was designed as a result of the lack of information about the normal radiographic anatomy of this breed. Methods: Radiography of the distal phalanx and associated soft tissue structures of the front feet of 10 healthy pure Iranian Arabian horses was performed on lateromedial radiographic projection to determine normal radiographic morphometry of this part. There were no problems in their limbs and in their history. Results: Obtained radiograph of each fron...
Leśniak K, Williams J, Kuznik K, Douglas P.Variation in equine hoof conformation between farriery interventions lacks research, despite associations with distal limb injuries. This study aimed to determine linear and angular hoof variations pre- and post-farriery within a four to six week shoeing/trimming interval. Seventeen hoof and distal limb measurements were drawn from lateral and anterior digital photographs from 26 horses pre- and post-farriery. Most lateral view variables changed significantly. Reductions of the dorsal wall, and weight bearing and coronary band lengths resulted in an increased vertical orientation of the hoof. ...
Lang HM, Schnabel LV, Cassano JM, Fortier LA.Mesenchymal stem cells (MSCs) are frequently delivered via needle injection for treatment of musculoskeletal injuries. The purpose of this study was to evaluate the effect of needle diameter on the viability of MSCs. Methods: Equine bone marrow-derived MSCs from 5 horses were suspended in PBS, and held at room temperature for 7 hours to mimic shipping conditions. Two replicate samples for each needle size (20, 22, 23, or 25-gauge [ga]) were aspirated into a 3 mL syringe and re-injected into the holding vial 3 times, to reproduce the resuspension of cells prior to injection in clinical cases. C...
Janeczek M, Chrószcz A, Onar V, Henklewski R, Skalec A.Animal remains that are unearthed during archaeological excavations often provide useful information about socio-cultural context, including human habits, beliefs, and ancestral relationships. In this report, we present pathologically altered equine first and second phalanges from an 11th century specimen that was excavated at Wrocław Cathedral Island, Poland. The results of gross examination, radiography, and computed tomography, indicate osteoarthritis of the proximal interphalangeal joint, with partial ankylosis. Based on comparison with living modern horses undergoing lameness examination...
Symons JE, Hawkins DA, Fyhrie DP, Upadhyaya SK, Stover SM.The metacarpophalangeal joint (fetlock) is the most commonly affected site of racehorse injury, with multiple observed pathologies consistent with extreme fetlock dorsiflexion. Race surface mechanics affect musculoskeletal structure loading and injury risk because surface forces applied to the hoof affect limb motions. Race surface mechanics are a function of controllable factors. Thus, race surface design has the potential to reduce the incidence of musculoskeletal injury through modulation of limb motions. However, the relationship between race surface mechanics and racehorse limb motions is...
Steinbusch MM, Fang Y, Milner PI, Clegg PD, Young DA, Welting TJ, Peffers MJ.The development of effective treatments for the age-related disease osteoarthritis and the ability to predict disease progression has been hampered by the lack of biomarkers able to demonstrate the course of the disease. Profiling the expression patterns of small nucleolar RNAs (snoRNAs) in joint ageing and OA may provide diagnostic biomarkers and therapeutic targets. This study determined expression patterns of snoRNAs in joint ageing and OA and examined them as potential biomarkers. Using SnoRNASeq and real-time quantitative PCR (qRT-PCR) we demonstrate snoRNA expression levels in murine age...
Holt D, St George LB, Clayton HM, Hobbs SJ.Previous studies have validated methods for determining kinematic gait events using threshold-based techniques. However, a simple method that can be successfully applied to walk, trot and canter is yet to be identified. Objective: To develop a simple kinematic method to identify the timing of hoof contact (hoof-on), peak vertical force and lift off (hoof-off), which can be applied in walk, trot and canter. Methods: In vivo method authentication study. Methods: Horses (n = 3) were ridden in walk, trot and canter down a runway on which four force plates were arranged linearly. Three-dimensional ...
Dunkel B, Pfau T, Fiske-Jackson A, Veres-Nyeki KO, Fairhurst H, Jackson K, Chang YM, Bolt DM.To investigate whether acupuncture can alter gait in horses as assessed by objective and subjective parameters. Methods: Prospective, randomized, singleblinded, crossover study. Methods: Eight adult horses. Methods: Horses were randomly assigned to a treatment (three acupuncture treatments in 8 days) or control group. Subjective and objective gait analyses were performed before and after each treatment and at 1, 3 and 7 days after the last treatment (time-points 1-9, respectively). Horses were assessed at the trot in a straight line on a hard surface and on the lunge on the left and right rein...
Zahedi M, Parham A, Dehghani H, Mehrjerdi HK.Application of competent cells such as mesenchymal stem cells (MSCs) for treatment of musculoskeletal disorders in equine athletes is increasingly needed. Moreover, similarities of horse and human in size, load and types of joint injuries, make horse as a good model for MSCs therapy studies. This study was designed to isolate and characterize stemness signature of equine bone marrow-derived mesenchymal stem cells (BM-MSCs). Methods: BM of three mares was aspirated and the mononuclear cells (MNCs) were isolated using density gradient. The primary MNCs were cultured and analyzed after tree passa...
Moorman VJ, Frisbie DD, Kawcak CE, McIlwraith CW.OBJECTIVE To determine the effects of altering location of right forelimb and pelvic sensors on kinematic data obtained with a commonly used inertial sensor system during gait analysis of trotting horses. DESIGN Experimental study. ANIMALS 12 horses with mild to moderate lameness of at least 1 hind limb, with or without lameness of the forelimbs. PROCEDURES All horses were examined while trotting on a high-speed treadmill. The right forelimb sensor was tested at 3 anatomic locations in random order: dorsal midline and 2 cm medial and lateral to that midline. During another treadmill session, t...
Stover SM.Racehorses are susceptible to bone fractures when damage from repetitive, high-magnitude loads incurred during training and racing exceed concurrent damage removal and replacement, resulting in transient periods of focal osteoporosis and bone weakening. Clinically, these events correspond to cortical stress fractures and subchondral bone stress remodeling. Evidence of these preexisting lesions include periosteal callus, endosteal callus, and intracortical focal hyperemia for cortical stress fractures; and subchondral focal hyperemia located superficial to sclerotic compacted trabecular bone ti...
Tamura N, Nukada T, Kato T, Kuroda T, Kotoyori Y, Fukuda K, Kasashima Y.The objective assessment of the mechanical properties of the superficial digital flexor tendon (SDFT) could provide useful information for the rehabilitation of horses with SDFT injuries. Assessment of strain ratio (the strain of a standard reference divided by that of lesions) is a quantitative method in sonoelastography for evaluating tissue stiffness in vivo. As yet, no longitudinal studies have used strain ratio to evaluate the progression of stiffness in SDFT injuries. Objective: To test the hypothesis that strain ratio can evaluate the recovery of stiffness during the healing of SDFT inj...
Nauwelaerts S, Hobbs SJ, Back W.Ground reaction forces in sound horses with asymmetric hooves show systematic differences in the horizontal braking force and relative timing of break-over. The Center Of Pressure (COP) path quantifies the dynamic load distribution under the hoof in a moving horse. The objective was to test whether anatomical asymmetry, quantified by the difference in dorsal wall angle between the left and right forelimbs, correlates with asymmetry in the COP path between these limbs. In addition, repeatability of the COP path was investigated. Methods: A larger group (n = 31) visually sound horses with variou...
Clayton HM, Schamhardt HC, Hobbs SJ.In this study, sagittal plane ground reaction forces (GRFs) in ridden elite dressage horses performing 'collected trot' and in 'passage' over ground were determined. In-ground force plates captured GRF data from four Dutch Warmblood and four Lusitano horses ridden by their trainers. At least three stance phases were analysed for forelimbs and hind limbs per horse. The variables extracted were vertical and longitudinal (braking, propulsive) force maxima, their times of occurrence and the respective impulses for forelimbs and hind limbs. Lusitanos had lower vertical impulses than Dutch Warmblood...
Findley JA, Ricci EE, Singer EE.The main aim was to describe the gross and histological appearance of the equine manica flexoria and to identify any differences between the forelimbs and hindlimbs. An additional aim was to relate the findings to diagnostic and surgical anatomy of the manica flexoria. Methods: Measurements of the manica flexoria were made on cadaveric limbs from horses free from pathology within the digital flexor tendon sheath. Histological sections, stained with haematoxylin and eosin and alcian- periodic acid schiff, were evaluated based on three micro-anatomical zones from dorsal to palmar or plantar. The...
Russell JW, Hall MS, Kelly GM.A 3-year-old Thoroughbred gelding was presented with a grade 3/5 lameness of the right forelimb and effusion of the extensor carpi radialis tendon sheath (ECRTS). Radiographic and ultrasonographic examinations revealed an osteochondroma on the cranial aspect of the distal radius projecting into the fibrous lining of the ECRTS. An open surgical approach was used to remove the osteochondroma and some of the proliferative synovial tissue. Conclusions: Six months after surgery the clinical signs had resolved and the horse raced successfully.
Ehrle A, Ressel L, Ricci E, Singer ER.Pain related to the osseous thoracolumbar spine is common in the equine athlete, with minimal information available regarding soft tissue pathology. The aims of this study were to describe the anatomy of the equine SSL and ISL (supraspinous and interspinous ligaments) in detail and to assess the innervation of the ligaments and their myofascial attachments including the thoracolumbar fascia. Ten equine thoracolumbar spines (T15-L1) were dissected to define structure and anatomy of the SSL, ISL and adjacent myofascial attachments. Morphological evaluation included histology, electron microscopy...
Forterre F, Stoffel MH, Koch C, Precht C, Waschk M, Bürki A.Atlantoaxial instability has been reported in humans, dogs, equids and ruminants. The functional role of the atlantoaxial ligaments has only been described rudimentarily in equids and ruminants. The goal of the present cadaveric study was to compare the anatomy between the different species and to comparatively assess the role of the stabilizing ligaments of the atlantoaxial joint under sagittal shear loading in canine, equine, and bovine cervical spines. Methods: Three equine, bovine, and canine cadaveric specimens were investigated. Biomechanical testing was performed using a purpose built s...
Zeng X, Trask C, Kociolek AM.Horse riding is common in many occupations; however, there is currently no research evaluating exposure to whole-body vibration and mechanical shock on horseback. Methods: Whole-body vibration was measured on a cattle rancher during two 30 min horseback rides using a tri-axial accelerometer mounted on a western saddle. Vibration was summarized into standardized metrics, including the 8 hr equivalent root-mean-squared acceleration (A[8]) and the daily 4th power vibration dose value (VDV). The resulting exposures were compared to the exposure limit and action values provided by European Unio...
Colbath AC, Dow SW, Phillips JN, McIlwraith CW, Goodrich LR.The use of allogeneic bone marrow-derived mesenchymal stem cells (BMDMSCs) may provide an effective alternative to autologous BMDMSCs for treatment of equine musculoskeletal injuries. However, concerns have been raised regarding the potential safety and effectiveness of allogeneic BMDMSCs. We conducted studies to assess the immunological properties of equine allogeneic BMDMSCs compared with those of autologous BMDMSCs. For assessment of inherent immunogenicity, the relative ability of allogeneic and autologous BMDMSCs to stimulate spontaneous proliferation of equine lymphocytes was compared. T...
Greve L, Pfau T, Dyson S.Equine movement symmetry is changed when turning, which may induce alterations in thoracolumbosacral kinematics; however, this has not previously been investigated. Our objectives were to document thoracolumbar movement in subjectively sound horses comparing straight lines with circles on both reins and to relate these observations to the objectively determined symmetry/asymmetry of hindlimb gait. Fourteen non-lame horses were assessed prospectively in a non-random, cross-sectional survey. The horses were trotted in straight lines and lunged on both reins and inertial sensor data collected at ...
Park JW, Choi JY, Hong SA, Kim NY, Do KT, Song KD, Cho BW.This study was performed to reveal the molecular structure and expression patterns of horse glutamate-cysteine ligase catalytic subunit () and glutamate-cysteine ligase modifier subunit () genes whose products form glutamate cysteine ligase, which were identified as differentially expressed genes in the previous study. Methods: We performed bioinformatics analyses, and gene expression assay with quantitative polymerase chain reaction (qPCR) for horse and genes in muscle and blood leukocytes of Thoroughbred horses. Results: Expression of showed the same pattern in both blood and muscle tissu...
Nürnberger S, Rentenberger C, Thiel K, Schädl B, Grunwald I, Ponomarev I, Marlovits S, Meyer C, Barnewitz D.The present study reports for the first time the presence of giant crystals in mitochondria of equine chondrocytes. These structures show dark contrast in TEM images as well as a granular substructure of regularly aligned 1-2 nm small units. Different zone axes of the crystalline structure were analysed by means of Fourier transformation of lattice-resolution TEM images proving the crystalline nature of the structure. Elemental analysis reveals a high content of nitrogen referring to protein. The outer shape of the crystals is geometrical with an up to hexagonal profile in cross sections. It ...
Gorissen BMC, Wolschrijn CF, Serra Bragança FM, Geerts AAJ, Leenders WOJL, Back W, van Weeren PR.Foals stand and walk immediately after birth, but insight into the subsequent longitudinal development of their gait kinetics in the early juvenile phase and the possible influence of osteochondrosis thereon is lacking. Objective: To quantify gait kinetics in foals during the first half year of life, taking into account their osteochondrosis status. Methods: Prospective, cohort study performed at a single stud farm. Methods: Pressure plate measurements at walk and trot from 11 Dutch Warmblood foals during the first 24 weeks of life were used to determine body mass normalised peak vertical forc...
Endruweit M, Dargel J, Siewe J, Becker I, Sobottke R.Background: Vaulting is the least studied equestrian sports regarding the occurrence of injuries. As its sequences of motion do not compare to riding, vaulting must be assessed separately. Material and Methods: This retrospective, questionnaire-aided survey was aimed to gain insight into the overall frequency of injuries among equestrian vaulters. The second part of the study looked into the knee injuries that occurred. Survey forms were sent to 60 vaulting and equestrian clubs all over Germany, making for a response rate of 63 %. Results: 95 % of 624 responding athletes were female. The p...
Georgopoulos SP, Parkin TD.The aim of this paper is to identify risk factors associated with equine fractures in flat horse racing of Thoroughbreds in North America. Equine fractures were defined as any fracture sustained by a horse during a race. This was a cohort study that made use of all starts from the racecourses reporting injuries. The analysis was based on 2,201,152 racing starts that represent 91% of all official racing starts in the USA and Canada from 1st January 2009-31st December 2014. Approximately 3,990,000 workout starts made by the 171,523 Thoroughbreds that raced during that period were also included i...
Schröter C, Bielefeld M, Bielefeld D, Macke C, Winkelmann C, Mommsen P, Krettek C, Zeckey C.The upper limb is one of the most frequently injured body regions in equestrian sports, but it is unclear which injuries are involved, and there are no data on the associated accident mechanism. The present study is aimed at evaluating the accident mechanisms, injuries of the upper limbs, and the circumstances of the accident in equestrian sports. We included 218 patients who were all treated between 2006 and 2014 at the level I trauma center at the Medical University in Hannover because of equestrian-related accidents. The most frequent injuries were fractures and bruising in the shoulder ...
Schutten KJ.A 12-year-old Standardbred mare was diagnosed with a ruptured prepubic tendon 1 month prepartum. The mare was treated with analgesia, stall rest, and an abdominal support wrap that was tightened daily. Both a live foal born 1 month later and the mare are doing well. Poulinage réussi par une jument Standardbred ayant une rupture du tendon prépubien. Un mois avant la parturition, une rupture du tendon prépubien a été diagnostiquée chez une jument Standardbred âgée de 12 ans. La jument a été traitée à l’aide d’analgésiques, d’un repos en stalles et d’un pansement de soutien r...
Okuda Y, Moe HH, Moe KK, Shimizu Y, Nishioka K, Shimogiri T, Mannen H, Kanemaki M, Kunieda T.Myanmar native horses are small horses used mainly for drafting carts or carriages in rural areas and packing loads in mountainy areas. In the present study, we investigated genotype distributions and allele frequencies of the LCORL/NCAPG, MSTN and DMRT3 genes, which are associated with body composition and locomotion traits of horses, in seven local populations of Myanmar native horses. The genotyping result of LCORL/NCAPG showed that allele frequencies of C allele associated with higher withers height ranged from 0.08 to 0.27, and 0.13 in average. For MSTN, allele frequencies of C allele ass...
Loscher DM, Meyer F, Kracht K, Nyakatura JA.Many ungulates show a conspicuous nodding motion of the head when walking. Until now, the functional significance of this behaviour remained unclear. Combining in vivo kinematics of quadrupedal mammals with a computer model, we show that the timing of vertical displacements of the head and neck is consistent with minimizing energy expenditure for carrying these body parts in an inverted pendulum walking gait. Varying the timing of head movements in the model resulted in increased metabolic cost estimate for carrying the head and neck of up to 63%. Oscillations of the head-neck unit result in w...
Zsoldos RR, Voegele A, Krueger B, Schroeder U, Weber A, Licka TF.The equine m. gluteus medius (GM) is the largest muscle of the horse, its main movement function is the extension of the hip joint. The objective of the present study was to measure equine GM activity in three adjacent locations on GM during walk and trot on a treadmill, in order to document potential differences. Fourteen Haflinger mares were measured using surface electromyography and kinematic markers to identify the motion cycles on three occasions over 16 weeks. The electrodes were placed on left and right gluteus medius muscle over the middle of its widest part and 5 cm lateral and med...
Barrett MF, Frisbie DD, McIlwraith CW, Werpy NM.While descriptions of the visible soft tissues of the femorotibial joints exist for both arthroscopy and ultrasonography, there are few examples in the literature that discuss in detail the combined findings of these modalities. Objective: To further elucidate the ultrasonographic and arthroscopic boundaries of the normal equine femorotibial joints and improve the understanding of the benefits and limitations of each individual modality. Methods: Simultaneous arthroscopy and ultrasonography were performed in 10 equine cadaver stifles as well as bilateral stifles on a horse that underwent nonre...
Kold SE, Hickman J, Melsen F.Four full thickness cartilage defects, two linear and two elliptical, and four subchondral cavity defects were created at the point of weightbearing of the medial femoral condyle in four experimental ponies. This study showed that subchondral bone cysts can develop following full thickness (cartilage only) linear cartilage defects at a weightbearing location. Subchondral bone cysts did not develop following the removal of an elliptical piece of cartilage, exposing the subchondral bone. Primary subchondral defects created in communication with the joint cavity did not heal by replacement with b...
Masko M, Krajewska A, Zdrojkowski L, Domino M, Gajewski Z.Leisure riding is a popular way of using horses however, unlike sport or racing horses, those are mostly not associated with one rider with high skills. Constant overload of equine musculoskeletal system causes pathologies, which are affecting horse mobility and decreases the horse-rider communication. The aim was to propose the new scoring system of thermograph analysis as an aspect of differences in heat distributions on horseback before and after leisure ridings. The study was conducted on sixteen Polish warmblood horses, scanned with a non-contact thermographic camera. Heat pattern of t...
Pezzanite LM, Easley JT, Bayless R, Aldrich E, Nelson BB, Seim HB, Nout-Lomas YS.Further development of surgical techniques for equine cervical stabilisation is necessary to make the procedure less technically demanding, reduce complications and improve outcomes. Objective: To describe clinical outcomes and owner reports in horses undergoing placement of an interbody fusion device and polyaxial pedicle screw and rod construct for cervical vertebral fusion in horses with cervical vertebral compressive myelopathy. Methods: Retrospective case series. Methods: Data were retrieved from medical records of 10 horses undergoing cervical vertebral fusion (2015-2019). Records were e...
Agar C, Gemmill R, Hollands T, Freeman SL.The aim of the study was to determine which types of nutritional supplements were used in dressage and eventing horses, and the reasons that owners used supplements. An online questionnaire was distributed through British Eventing and Dressage websites, to collect data on demographics of owners and their horses, supplements used and their opinion on health and performance problems. Data were evaluated using descriptive analysis, Sign and Fisher's exact tests for quantitative data, and categorisation of qualitative data. In total, 599 responses met the inclusion criteria (441 dressage and 158 e...
Bertone AL, Tremaine WH, Macoris DG, Simmons EJ, Ewert KM, Herr LG, Weisbrode SE.To evaluate clinical safety of administration of injectable enrofloxacin. Methods: Randomized controlled clinical trial. Methods: 24 adult horses. Methods: Healthy horses were randomly allocated into 4 equal groups that received placebo injections (control) or IV administration of enrofloxacin (5 mg/kg [2.3 mg/lb], 15 mg/kg [6.8 mg/lb], or 25 mg/kg [11.4 mg/lb] of body weight, q 24 h) for 21 days. Joint angles, cross-sectional area of superficial and deep digital flexor and calcaneal tendons, carpal or tarsal osteophytes or lucency, and midcarpal and tarsocrural articular cartilage lesions wer...
Firth EC, van Weeren PR, Pfeiffer DU, Delahunt J, Barneveld A.This study aimed a the determining bone mineral density (BMD) in the 3rd carpal bone and distal radius of foals age 5 and 11 months that had been subjected to different exercise regimens from birth until age 5 months. It was hypothesised that BMD would be greater in older animals, and that differences in exercise regimens before age 5 months would be associated with differences in BMD at both age 5 and 11 months. Epiphyseal bone tissue was available from 5 and 11 month old Warmblood foals bred from sires known to have radiographic evidence of osteochondrosis (OC). The foals were in a clinical ...
Bullimore SR, Burn JF.It is possible for animals of very different sizes to use the same patterns of locomotion, i.e. to move in a ;dynamically similar fashion'. This will only occur, however, if relevant biomechanical parameters scale with size in such a way that they compensate for the effects of size differences. Here we apply this principle to understanding the effects of size on locomotion within a species: the domestic horse. We predict that, without any factor to compensate for size differences, detectable deviations from dynamically similar locomotion would occur over the size range present in adult horses....
Cresswell EN, Ruspi BD, Wollman CW, Peal BT, Deng S, Toler AB, McDonough SP, Palmer SE, Reesink HL.To examine whether proximal sesamoid bone (PSB) articular cartilage and bone osteoarthritic changes or palmar osteochondral disease (POD) scores were associated with exercise history and catastrophic PSB fracture in Thoroughbred racehorses. Methods: PSBs from 16 Thoroughbred racehorses (8 with and 8 without PSB fracture). Methods: Exercise history was collected, and total career high-speed furlongs was used as the measure of total exercise per horse. At necropsy, medial and lateral condyles of the third metacarpus from each forelimb were assigned a POD score, followed by imaging with micro-CT ...
Mukai K, Kitaoka Y, Takahashi Y, Takahashi T, Takahashi K, Ohmura H.We investigated whether moderate-intensity training of horses in moderate hypoxia for 4 weeks elicits greater adaptations in exercise performance, aerobic capacity, and glycolytic/oxidative metabolism in skeletal muscle compared to normoxic training. In a randomized crossover study design, seven untrained Thoroughbred horses (5.9 ± 1.1 years, 508 ± 9 kg) completed 4 weeks (3 sessions/week) of two training protocols consisting of 3-min cantering at 70% of maximal oxygen consumption ( ) in hypoxia (HYP; F O = 14.7%) and normoxia (NOR; F O = 21.0%) with a 4-month washout period....
Yamano S, Kawai M, Minami Y, Hiraga A, Miyata H.We evaluated differences in muscle fiber recruitment patterns between continuous and interval training to develop an optimal training program for Thoroughbred horses. Five well trained female thoroughbred horses (3-4 years old) were used. The horses performed two different exercises on a 10% inclined treadmill: 90%VO2 max for 4 min (continuous) and 90% VO2 max for 2 min × 2 times with 10-min interval (interval). Muscle samples were obtained from the middle gluteal muscle before and immediately after the exercises. Four muscle fiber types (type I, IIA, IIA/X, and IIX) were immunohistochemicall...
Starke SD, Willems E, Head M, May SA, Pfau T.Flexion tests are a common tool during the prepurchase and clinical lameness examination, yet studies quantifying the effect of flexion, apart from distal forelimb flexion in sound horses, are sparse. Objective: To investigate the effect of proximal hindlimb flexion on perceivable and measurable changes in movement symmetry in horses with objective movement symmetry falling within the margins of 'sound'. Methods: Thirteen horses, selected based on objective movement symmetry, were instrumented with inertial sensors on left and right tuber coxae and over the os sacrum. Vertical movement symmetr...
Yamano S, Eto D, Kasashima Y, Hiraga A, Sugiura T, Miyata H.To determine the growth-related changes in metabolic and anatomic properties in equine muscle fiber type, including hybrid fibers identified with immunohistochemical analysis. Methods: 24 2-, 6-, 12-, and 24-month-old female Thoroughbreds. Methods: Samples were obtained from the gluteus medius muscle of all horses. Expression of myosin heavy chain (MHC) isoforms MHC-I, -IIa, -IIb, and -IIx in each muscle fiber was detected by use of 4 primary monoclonal antibodies: BA-D5, SC-71, BF-F3, and BF-35, respectively. Five muscle fiber types (types I, I/IIA, IIA, IIA/IIX, and IIX) were immunohistochem...
Latham CM, Fenger CK, White SH.Responses of equine skeletal muscle characteristics to growth and training have been shown to differ between breeds. These differential responses may arise in part because muscle fiber type and mitochondrial density differ between breeds, even in untrained racing-bred horses. However, it is not known when these breed-specific differences manifest. To test the hypothesis that weanling Standardbreds (SB) and Thoroughbreds (TB) would have higher mitochondrial measures than Quarter Horses (QH), gluteus medius samples were collected from SB (mean ± SD; 6.2 ± 1.0 mo; n = 10), TB (6.1 ± 0.5 mo; n ...
Ryan JM, Cobb MA, Hermanson JW.Based on histochemical and immunohistochemical evidence, horse elbow extensor muscles are composed of two morphologically distinct muscle groups. The long and lateral heads of the triceps brachii are large, predominantly type II (presumed fast) muscles. The long and lateral heads of the triceps together account for 96% of the weight of the elbow extensors (long head of triceps is 81%). The long and lateral heads contain three histochemical fiber types: types I, IIa and IIb. Type I muscle fibers account for approximately 18 and 27% of the fibers in the long and lateral heads of the triceps, res...
Hill AE, Stover SM, Gardner IA, Kane AJ, Whitcomb MB, Emerson AG.To evaluate effects of toe grabs, exercise intensity, and distance traveled as risk factors for subclinical to mild suspensory apparatus injury (SMSAI) in Thoroughbred racehorses and to compare incidence of severe musculoskeletal injury (MSI) in horses with and without SMSAI. Methods: Nested case-control study. Methods: 219 Thoroughbred racehorses racing or in race training. Methods: Racehorses were examined weekly for 90 days to determine incidence of suspensory ligament injury and monitor horseshoe characteristics. Every horse's exercise speeds and distances were recorded daily. Conditional ...
Bowser JE, Elder SH, Pasquali M, Grady JG, Rashmir-Raven AM, Wills R, Swiderski CE.Hereditary equine regional dermal asthenia (HERDA) is an autosomal recessive disorder of Quarter Horses characterised by skin fragility. Horses with HERDA have a missense mutation in peptidyl-prolyl cis-trans isomerase B (PPIB), which encodes cyclophilin B and alters folding and post translational modifications of fibrillar collagen. Objective: The study aimed to test the hypothesis that tendons, ligaments and great vessels, which, like skin, are rich in fibrillar collagen, will also have abnormal biomechanical properties in horses with HERDA. Methods: Ex vivo biomechanical study comparing...
Kim MJ, Kim T, Oh S, Yoon B.Horseback riding is an effective exercise for improving postural control and balance. To reduce costs and improve accessibility, simulated horseback riding has been developed; but no differential effects of simulated and real horseback riding on muscle activation patterns in older adults have been studied. Thus, we compared muscle activation patterns for older and younger adults engaged in real and simulated horseback riding exercises, using surface electromyography recordings of the erector spinae, rectus abdominis, internal oblique abdominis, and rectus femoris muscles. We recorded muscle ac...
Verheyen KL, Price JS, Wood JL.This study aimed to determine the effects of exercise on racecourse performance in horses racing on the flat. Daily exercise and race records were obtained over a 2-year period for a cohort of racehorses in training for which injury data were also available. Multivariable regression techniques were used to investigate associations between canter, training gallop and race distances accumulated in the 30 days prior to each race and the odds of winning the race, earning prize money and the amount of prize money won. Higher cumulative high-speed (gallop+race) distances were associated with increas...
Meyers RA, Hermanson JW.The soleus muscle of horses is rather diminutive with respect to the overall size of adjacent synergist muscles in the hind limb of the horse. Whether or not such a muscle might be vestigial or may be providing some essential function has not been determined. We have studied the horse's soleus muscle using histochemical (ATPase), immunocytochemical (myosin isoform identification), and SDS-PAGE analysis to demonstrate that it is largely composed of 100% type I, presumed slow-twitch fibers. Only one soleus muscle studied (out of 13 adult horses) contained any type II muscle fibers. Given this co...
Staszyk C, Gasse H.The periodontal ligament (PDL) of the hypsodont cheek teeth of the horse meets specific requirements of tooth support: (1) to fix the tooth; (2) to withstand pressure and tension during the laterolateral mastication movement; (3) to restore the original tooth position. These requirements are assumed to be met by the periodontal collagen fiber apparatus and by the vascular system. Distinct fibro-vascular arrangements are described here in order to reveal the structural prerequisites for these distinct functions. Methods: Specimens from nine horses were processed for (1) collagen labeling with f...
Gibson MJ, Legg KA, Gee EK, Rogers CW.Race day fatalities as a consequence of catastrophic musculoskeletal injury and cardiac failure are both a welfare concern and provide a challenge for the social perceptions of equine welfare within the racing industry. To reduce race day fatalities, the risk factors under New Zealand racing conditions need to be identified. The aim of this study was to examine race and horse-level risk factors for fatalities in New Zealand Thoroughbred flat racing using retrospective race day data from the 2011/12-2021/22 racing seasons. Horse and race-level factors associated with a suspected cardiac failure...
Jackson WA, Stick JA, Arnoczky SP, Nickels FA.To compare the quality of second-intention healing and that of compacting sternally harvested cancellous bone into subchondral bone defects of the medial femoral condyle in horses. Methods: A controlled experiment using a surgical technique that minimizes soft tissue trauma, customized for consistency among horses. Methods: Ten horses, aged 2 to 5 years, free of hindlimb lameness and with radiographically normal stifles. Methods: After a 12.7-mm-diameter x 19-mm-deep defect was created into randomly selected medial femoral condyles, bone and cartilage healing was evaluated over a 6-month perio...
Jönsson L, Roepstorff L, Egenvall A, Näsholm A, Dalin G, Philipsson J.Soundness of an individual horse is important for animal welfare and owner economy. However, knowledge of health status in normal horse populations is limited due to lack of systematic health recordings. The aim of the investigation was to study the prevalence of veterinary clinical findings in 4-5-year-old Swedish warmblood riding horses, and their influence on overall health scores, where associations to future longevity has been indicated. Results: The prevalence of clinical findings in 8,281 horses examined during 1983-2005 was studied according to a standardised protocol and related to ov...
Pösö AR, Eklund-Uusitalo S, Hyyppä S, Pirilä E.In response to stress, cells synthesise heat shock proteins (HSP) to maintain protein homeostasis. To study whether exercise and training induce expression of HSP72 in the middle gluteal muscle, 10 Finnhorses performed a submaximal 60 min exercise test on a treadmill. Test A was performed after 3 months of training, and the other two tests 2 (B) and 5 (C) weeks later. Blood samples were taken during and after the tests, and biopsy samples before, immediately after and 23 h after each test. HSP72 mRNA was analysed using a digoxigenin-labelled probe. Blood lactate concentration in the 3 tests va...
Alzola R, Easter C, Riggs CM, Gardner DS, Freeman SL.Superficial digital flexor tendon (SDFT) injury is an important health and welfare concern in racehorses. It is generally diagnosed with ultrasonography, but predictive ultrasonographic features have not been reported. Objective: To determine ultrasonographic features of forelimb SDFT injury at initial presentation in Thoroughbred racehorses that could predict a successful return to racing (completing ≥5 races). Methods: Retrospective cohort study. Methods: Digitised ultrasonographic images of 469 horses with forelimb SDFT injuries from the Hong Kong Jockey Club (2003-2014) were evaluated, u...
Back W, Schamhardt HC, Barneveld A.In purchase examinations or at studbook selection sales the locomotor apparatus of horses is judged both at walk and trot. To evaluate whether kinematics of the walk are related to the locomotion at the trot, fore and hind limb movements of a group of 24 26-month-old warmbloods were recorded at walk and trot on a treadmill (1.6 and 4 m/s) using a modified CODA-3 gait analysis system. The intralimb coordination patterns at walk and trot were compared, and temporal and spatial variables of these gaits were related. Stride and stance durations (s) were shorter at the trot, while the stance distan...
Hoyt DF, Wickler SJ, Garcia SF.Although there have been reports of oxygen consumption measurements of horses running on the level and incline, there are no measurements during decline locomotion. This may be due, in part, to the potential for muscle damage produced by eccentric contractions. In man, running on a 10% decline, VO2 decreased by 35% and stride frequency (SF) decreased by 3% when compared to level locomotion. Objective: The rate of O2 consumption and SF would be decreased in horses on a 10% decline when compared to the level. Methods: Six horses (average 467 +/- 68 kg) were acclimated to trotting on the level an...
Jeffcott LB.A description of some of the clinical features of low back pain in the horse has been given and a number of methods for assisting diagnosis considered. As well as a complete clinical examination both at rest and during exercise, a useful diagnostic aid in some chronic cases was the injection of local anaesthetic into the interspinous spaces. A laboratory examination, including haematological and biochemical profiles, was undertaken in all cases. The serum enzymes GOT and CPK were particularly valuable as an aid to diagnosis in atypical tying-up. A technique for radiography of the vertebral col...
