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Author Meershoek, L.S.; Roepstorff, L.; Schamhardt, H.C.; Johnston, C.; Bobbert, M.F. openurl 
  Title (up) Joint moments in the distal forelimbs of jumping horses during landing Type Journal Article
  Year 2001 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J  
  Volume 33 Issue 4 Pages 410-415  
  Keywords Animals; Biomechanics; Forelimb/physiology; Gait/*physiology; Horses/*physiology; Joints/*physiology; Physical Conditioning, Animal; Tendons/*physiology; Weight-Bearing  
  Abstract Tendon injuries are an important problem in athletic horses and are probably caused by excessive loading of the tendons during demanding activities. As a first step towards understanding these injuries, the tendon loading was quantified during jump landings. Kinematics and ground reaction forces were collected from the leading and trailing forelimbs of 6 experienced jumping horses. Joint moments were calculated using inverse dynamic analysis. It was found that the variation of movement and loading patterns was small, both within and between horses. The peak flexor joint moments in the coffin and fetlock joints were larger in the trailing limb (-0.62 and -2.44 Nm/kg bwt, respectively) than in the leading limb (-0.44 and -1.93 Nm/kg bwt, respectively) and exceeded literature values for trot by 82 and 45%. Additionally, there was an extensor coffin joint moment in the first half of the stance phase of the leading limb (peak value 0.26+/-0.18 Nm/kg bwt). From these results, it was concluded that the loading of the flexor tendons during landing was higher in the trailing than in the leading limb and that there was an unexpected loading of the extensor tendon in the leading limb.  
  Address Department of Veterinary Anatomy and Physiology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:11469776 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3787  
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Author Santamaria, S.; Back, W.; van Weeren, P.R.; Knaap, J.; Barneveld, A. openurl 
  Title (up) Jumping characteristics of naive foals: lead changes and description of temporal and linear parameters Type Journal Article
  Year 2002 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl  
  Volume Issue 34 Pages 302-307  
  Keywords Animals; Animals, Newborn/*physiology; Biomechanics; Female; Forelimb/physiology; Gait/*physiology; Hindlimb/physiology; Horses/*physiology; Locomotion/*physiology; Male  
  Abstract The selection of foals as future showjumpers remains a subjective process based on qualitative parameters; and hence, frequently suffers from disparity in the criteria used by experts in the field. A detailed biomechanical description of foals while jumping would be most helpful in providing a better basis for the accurate assessment of their future athletic ability. The Qualisys Pro Reflex system was used to capture 3-dimensional kinematics of 41 Dutch Warmblood foals age 6 months free jumping a vertical fence, preceded by a cross pole fence. The left lead was the most preferred lead for both the fore- and hindlimbs, from the landing following the cross poles to the first move-off stride after clearing the vertical fence. The foals displayed a high incidence of rotary gallop during both the jump stride (divided into take-off, jump suspension and landing) and the first move-off stride, while change of lead was frequently observed during jump suspension. At the take-off side of the fence, the trailing forelimb in the last approach stride was placed furthest from the fence, whereas the trailing hindlimb at take-off was placed closest (P<0.05). At the landing side, the trailing forelimb was the closest and the leading hindlimb of the move-off stride 1 was the furthest (P<0.05). The trailing forelimb in the approach stride 1 had a significantly longer stance phase duration than the leading forelimb. At landing, the leading forelimb stance phase lasted longer than that of the trailing forelimb (P<0.05). The hindlimbs did not differ in their stance phase duration at take-off. The height reached by the hooves above the fence top was significantly greater in the hind limbs (P<0.05). In addition, the hindlimbs (97.1 +/- 2.6%) shortened more than the forelimbs (92.6 +/- 5.7%) (P<0.05). It is concluded that the overall jumping technique of foals is similar to that reported in literature for mature horses. If the patterns are consistent throughout the rearing period, the quantitative analysis of the kinematics of free jumping foals may provide a valid quantitative basis for early selection.  
  Address Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht, The Netherlands  
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  Language English Summary Language Original Title  
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  Area Expedition Conference  
  Notes PMID:12405705 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3784  
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Author McGreevy, P.D.; Rogers, L.J. doi  openurl
  Title (up) Motor and sensory laterality in thoroughbred horses Type Journal Article
  Year 2005 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 92 Issue 4 Pages 337-352  
  Keywords Horse; Lateralisation; Training; Olfaction; Forelimb preference  
  Abstract We investigated lateralisation in horses because it is likely to be important in training and athletic performance. Thoroughbred horses (n = 106) were observed every 60 s for 2 h, when they were at pasture, and the position of the forelimbs in relation to one another was recorded. There was a population bias skewed to standing with the left forelimb advanced over the right (i.e. directional lateralisation). Using the first 50 observations, the distribution of preferences was 43 significantly left, 10 significantly right with 53 being non-significant (i.e. ambidextextrous). The strength of motor bias increased with age, suggesting maturation or an influence of training. The horses were also presented with an olfactory stimulus (stallion faeces) to score the tendency to use one nostril rather than the other. A significant preference to use the right nostril first was shown in horses under 4 years of age (n = 61) but not in older horses. Of the 157 horses tested for nostril bias, 76 had been assessed for motor bias and so were used for analysis of the relationship between laterality in the two modalities. There was no significant relationship between direction of foreleg motor bias and first nostril used, total number of inhalations or laterality index of nostril use. The absence of a correlation between laterality of nostril use and motor bias indicates that lateralisation of the equine brain occurs on at least two levels of neural organisation--sensory and motor--a finding that is consistent with other examples of lateralisation in species that have been examined in more detail.  
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  Call Number Equine Behaviour @ team @ room 3.029 Serial 1827  
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Author Seghrouchni, M.; Elkasraoui, H.; Piro, M.; Alyakine, H.; Bouayad, H.; Chakir, J.; Tligui, N.; Elallali, K.; Azrib, R. url  doi
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  Title (up) Osteoarticular radiographic findings of the distal forelimbs in Tbourida Horses Type Journal Article
  Year 2019 Publication Heliyon Abbreviated Journal  
  Volume 5 Issue 9 Pages e02514  
  Keywords Animal science; Pathophysiology; Animal behavior; Animal breeding; Veterinary medicine; Veterinary science; Horse; Radiographic findings; Forelimb; X-ray; Tbourida  
  Abstract Tbourida is a traditional Moroccan equestrian sport in which 15 horses gallop 200 m in a line while riders fire into the sky with muskets. The stop is the finale and representative demands of this equestrian event. Such particular sudden stop after a fast gallop requires a hyperextension of the metacarpophalangeal joint. Indeed, it is well known that Tbourida show predisposes horses to different injuries of the hard and soft tissues of the distal forelimbs. Yet, there is a paucity of research that examined such lesions. The aim of the present study was to investigate for the first time the type and the prevalence of osteoarticular findings in the distal forelimbs of Tbourida horses using radiographic images. The study was conducted on 127 Tbourida horses aged between 2.5 and 15 years old with 6-year-old horses being the most affected. Data analysis showed that 93,7% of horses exhibit degenerative joint lesions of the fetlock, 86,6% showed ossification of the ungual cartilage, 78,7% had enthesophytes associated with the deep digital flexor tendons, 81,1% had enthesophytes associated with the suspensory ligament branches, and 19,6% showed a particular exostosis on the first phalanx. This large number of lesions reflects how this sport is difficult for horses and also argues that animals are suffering from a lack of welfare and care in their husbandry management.  
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  ISSN 2405-8440 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 6672  
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Author Dyson, S.; Murray, R. openurl 
  Title (up) Pain associated with the sacroiliac joint region: a clinical study of 74 horses Type Journal Article
  Year 2003 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J  
  Volume 35 Issue 3 Pages 240-245  
  Keywords Age Factors; Analgesia/veterinary; Anesthetics, Local/pharmacology; Animals; Body Height; Body Weight; Breeding; Female; Forelimb; Gait; Hindlimb; Horse Diseases/*diagnosis/radionuclide imaging; Horses; Lameness, Animal/*physiopathology; Lumbar Vertebrae/physiopathology; Male; Pain/diagnosis/drug therapy/radionuclide imaging/*veterinary; Sacroiliac Joint/*physiopathology; Sacrum/physiopathology  
  Abstract REASONS FOR PERFORMING STUDY: There has been no large study of horses with suspected sacroiliac (SI) joint region pain in which the clinical diagnosis has been supported by either abnormal radiopharmaceutical activity in the SI joint region or by periarticular infiltration of local anaesthetic solution. OBJECTIVES: To describe the clinical features of horses with SI joint region pain, to document the age, breed, sex, discipline, size and conformation of affected horses and to compare these with the author's (SD) normal case population and to document the results of infiltration of local anaesthetic solution around the SI joint region. METHODS: Horses were selected for inclusion in the study based upon the exclusion of other causes of lameness or poor performance, together with clinical signs suggestive of SI joint pain and abnormal radiopharmaceutical activity in the SI joint region and/or a positive response to periarticular infiltration of local anaesthetic solution. RESULTS: Sacroiliac joint region disease was identified in 74 horses between November 1997 and March 2002. Dressage and showjumping horses appeared to be at particular risk (P < 0.001). Affected horses were generally slightly older than the normal clinic population (P < 0.0001), taller at the withers (P < 0.0001) and of greater bodyweight (P < 0.01). There was a significant effect of breed (P < 0.001), with a substantially higher proportion of Warmblood horses (51%) in the SI pain group compared to the normal clinic population (29%). There was no correlation between conformation and the presence of SI joint region pain. The tubera sacrale appeared grossly symmetrical in most (95%) horses. Poor development of the epaxial muscles in the thoracolumbar region and asymmetry of the hindquarter musculature were common. Twenty-six horses (35%) showed restricted flexibility of the thoracolumbar region and 10 (16%) had an exaggerated response to pressure applied over the tubera sacrale. Fourteen horses (19%) were reluctant to stand on one hindlimb for prolonged periods. The majority of horses (75%) had a straight hindlimb flight and only 18% moved closely behind or plaited. In all horses restricted hindlimb impulsion was the predominant feature; invariably this was most obvious when the horse was ridden. Stiffness, unwillingness to work on the bit and poor quality canter were common. Sacroiliac joint region pain was seen alone (47%), or in conjunction with thoracolumbar pain (16%), hindlimb lameness (20%), forelimb lameness (7%) or a combination of problems (10%). Seventy-three horses (99%) had abnormalities of the SI joint region identified using nuclear scintigraphy. Infiltration of local anaesthetic solution around the SI joint region produced profound improvement in gait in all 34 horses in which it was performed. CONCLUSIONS AND POTENTIAL RELEVANCE: Careful clinical examination combined with scintigraphic evaluation of the SI joint region and local analgesia can enable a more definitive diagnosis of SI joint region pain than has previously been possible.  
  Address Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12755425 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3723  
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Author Kraus-Hansen, A.E.; Fackelman, G.E.; Becker, C.; Williams, R.M.; Pipers, F.S. openurl 
  Title (up) Preliminary studies on the vascular anatomy of the equine superficial digital flexor tendon Type Journal Article
  Year 1992 Publication Equine veterinary journal Abbreviated Journal Equine Vet J  
  Volume 24 Issue 1 Pages 46-51  
  Keywords Angiography/veterinary; Animals; Exercise Test/veterinary; Forelimb; Horses/*anatomy & histology/surgery; Microcirculation; Microscopy, Electron, Scanning; Tendons/*blood supply/surgery/ultrastructure  
  Abstract The vascular and microvascular anatomy of normal equine superficial digital flexor tendons was studied by dissection of vinyl-perfused specimens and by microangiography on high detail film. The presence of an extensive intratendinous vascular latticework was confirmed, and a 'nutrient artery' described closely associated with the accessory ligament of the superficial digital flexor tendon (proximal check ligament). Circumferential stripping of the paratenon from the tendon to eliminate afferent vessels was performed bilaterally in three horses and unilaterally in a fourth, followed by a treadmill training regimen. No resulting intratendinous lesions could be documented on gross post mortem and histological examination at three, 10, or 35 days post operatively. There was mild paratendinous proliferation in all instances. In one horse, four intratendinous ligatures were placed within the medial and lateral borders of the contralateral tendon to isolate further from its blood supply a 10 cm segment. Gross lesions at 35 days post operatively included a marked paratendinous response involving the entire 10 cm segment, and a darkened, soft focus within the core of the tendon. Histopathology and electron microscopy demonstrated focal degeneration. It was concluded that the blood supply of the normal equine superficial digital flexor tendon is primarily intratendinous, rather than paratendinous as previously thought. The lesions in one horse similar to those in naturally occurring tendinitis supported a vascular aetiology of the disease, and set the groundwork for studies aimed at the development of a clinically relevant tendinitis model.  
  Address Department of Surgery, Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1555540 Approved no  
  Call Number refbase @ user @ Serial 151  
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Author Kasashima, Y.; Takahashi, T.; Smith, R.K.W.; Goodship, A.E.; Kuwano, A.; Ueno, T.; Hirano, S. openurl 
  Title (up) Prevalence of superficial digital flexor tendonitis and suspensory desmitis in Japanese Thoroughbred flat racehorses in 1999 Type Journal Article
  Year 2004 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J  
  Volume 36 Issue 4 Pages 346-350  
  Keywords Age Factors; Animals; Female; Forelimb; Hindlimb; Horse Diseases/*epidemiology/etiology; Horses; Inflammation/epidemiology/etiology/*veterinary; Japan/epidemiology; Ligaments/injuries/*pathology; Male; Musculoskeletal Diseases/epidemiology/etiology/veterinary; *Physical Conditioning, Animal; Prevalence; Retrospective Studies; Risk Factors; Sex Factors; Sports; Tendinopathy/epidemiology/etiology/*veterinary; Tendon Injuries/epidemiology/etiology/*veterinary  
  Abstract REASONS FOR PERFORMING STUDY: Overstrain injuries to the superficial digital flexor tendon (SDFT) and suspensory ligament (SI) are among the most common musculoskeletal injuries which contribute to the considerable wastage of racing Thoroughbreds. Many epidemiological studies have demonstrated the prevalence of and risk factors for tendon injury when racing but have not included those injuries sustained during training. However, since tendon injury during training is seen commonly in clinical practice, it is appropriate to determine the overall prevalence of tendon injury sustained during both training and racing. OBJECTIVE: To determine the prevalence of overstrain injury to the SDFT and SL during training and racing among Thoroughbred flat racehorses in Japan in 1999. METHODS: A retrospective study was performed using a sample population of 10,262 Thoroughbred racehorses. The medical information database of Thoroughbred racehorses registered by the Japan Racing Association (JRA) in 1999 was analysed for SDFT and SL overstrain injury diagnosed by a veterinarian employed by JRA during training and racing. Jump racehorses were excluded from this study. RESULTS: The prevalence of forelimb SDFT tendonitis and SL desmitis was 11.1% (1130 cases) and 3.61% (370 cases) of the population, respectively. In the hindlimb, there were 0.06% (6 cases) and 0.14% (14 cases), respectively. Risks of SDF tendonitis in the forelimb in 3-year-olds or older horses were significantly higher than in 2-year-olds. In contrast, the risk of SL desmitis in the forelimb at age 3 and 4 years was 2.23 and 2.11 times higher, respectively, than in 2-year-olds, but this increased to 5.07 times in those age > or = 5 years. Entire males were at greater risk in comparison to females and geldings. CONCLUSIONS: The results suggest that the prevalence of SDF tendonitis and SL desmitis in the forelimb was associated with the horse's age and sex. The prevalence of SL desmitis increased further with age compared with SDF tendonitis, possibly reflecting a more rapid accumulation of degeneration in this structure. POTENTIAL RELEVANCE: The age-related risk demonstrated in this study provides further support that overstrain injuries are associated with accumulated degeneration. These data provide a valuable resource for further research into the aetiology of tendon injury in the racehorse.  
  Address Equine Research Institute, Japan Racing Association, 321-4, Tokami-cho, Utsunomiya-shi, Tochigi, 320-0856, Japan  
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  Language English Summary Language Original Title  
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  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15163043 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3775  
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Author McGuigan, M.P.; Wilson, A.M. openurl 
  Title (up) The effect of gait and digital flexor muscle activation on limb compliance in the forelimb of the horse Equus caballus Type Journal Article
  Year 2003 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol  
  Volume 206 Issue Pt 8 Pages 1325-1336  
  Keywords Animals; Biomechanics; Forelimb/anatomy & histology/*physiology; Gait/*physiology; Horses/anatomy & histology/*physiology; Muscle Contraction/*physiology; Running  
  Abstract A horse's legs are compressed during the stance phase, storing and then returning elastic strain energy in spring-like muscle-tendon units. The arrangement of the muscle-tendon units around the lever-like joints means that as the leg shortens the muscle-tendon units are stretched. The forelimb anatomy means that the leg can be conceptually divided into two springs: the proximal spring, from the scapula to the elbow, and the distal spring, from the elbow to the foot. In this paper we report the results of a series of experiments testing the hypothesis that there is minimal scope for muscle contraction in either spring to adjust limb compliance. Firstly, we demonstrate that the distal, passive leg spring changes length by 127 mm (range 106-128 mm) at gallop and the proximal spring by 12 mm (9-15 mm). Secondly, we demonstrate that there is a linear relationship between limb force and metacarpo-phalangeal (MCP) joint angle that is minimally influenced by digital flexor muscle activation in vitro or as a function of gait in vivo. Finally, we determined the relationship between MCP joint angle and vertical ground-reaction force at trot and then predicted the forelimb peak vertical ground-reaction force during a 12 m s(-1) gallop on a treadmill. These were 12.79 N kg(-1) body mass (BM) (range 12.07-13.73 N kg(-1) BM) for the lead forelimb and 15.23 N kg(-1) BM (13.51-17.10 N kg(-1) BM) for the non-lead forelimb.  
  Address Structure and Motion Laboratory, Veterinary Basic Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK. m.p.mcguigan@leeds.ac.uk  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0022-0949 ISBN Medium  
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  Notes PMID:12624168 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3655  
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Author Schaer, B.L.D.; Ryan, C.T.; Boston, R.C.; Nunamaker, D.M. openurl 
  Title (up) The horse-racetrack interface: a preliminary study on the effect of shoeing on impact trauma using a novel wireless data acquisition system Type Journal Article
  Year 2006 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J  
  Volume 38 Issue 7 Pages 664-670  
  Keywords Animals; Equipment and Supplies/veterinary; Forelimb/injuries/physiology; Hindlimb/injuries/physiology; Hoof and Claw/*physiology; Horses/*injuries/*physiology; Locomotion/physiology; Muscle, Skeletal/injuries/*physiology; *Musculoskeletal Physiology; Musculoskeletal System/*injuries; Physical Conditioning, Animal/*physiology; Risk Factors; Running/physiology; Shoes  
  Abstract REASONS FOR PERFORMING STUDY: There is a need to determine accelerations acting on the equine hoof under field conditions in order to better assess the risks for orthopaedic health associated with shoeing practices and/or surface conditions. OBJECTIVES: To measure the acceleration profiles generated in Thoroughbred racehorses exercising at high speeds over dirt racetracks and specifically to evaluate the effect of a toe grab shoe compared to a flat racing plate, using a newly developed wireless data acquisition system (WDAS). METHODS: Four Thoroughbred racehorses in training and racing were used. Based on previous trials, each horse served as its own control for speed trials, with shoe type as variable. Horses were evaluated at speeds ranging from 12.0-17.3 m/sec. Impact accelerations, acceleration on break over and take-off, and temporal stride parameters were calculated. Impact injury scores were also determined, using peak accelerations and the time over which they occurred. RESULTS: Recorded accelerations for the resultant vector (all horses all speeds) calculated from triaxial accelerometers ranged 96.3-251.1 g, depending on the phase of the impact event. An association was observed between shoe type and change in acceleration in individual horses, with 2 horses having increased g on initial impact with toe grab shoes in place. In the final impact phase, one horse had an increase of 110 g while wearing toe grab shoes. Increased accelerations were also observed on break over in 2 horses while wearing toe grab shoes. CONCLUSIONS: Shoe type may change impact accelerations significantly in an individual horse and could represent increased risk for injury. Further work is needed to determine if trends exist across a population. POTENTIAL RELEVANCE: The WDAS could be used for performance evaluation in individual horses to evaluate any component of the horse-performance surface interface, with the goal of minimising risk and optimising performance.  
  Address Richard S. Reynolds Jr. Comparative Orthopedic Research Laboratory, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania 19348, USA  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17228583 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4024  
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Author Skedros, J.G.; Dayton, M.R.; Sybrowsky, C.L.; Bloebaum, R.D.; Bachus, K.N. doi  openurl
  Title (up) The influence of collagen fiber orientation and other histocompositional characteristics on the mechanical properties of equine cortical bone Type Journal Article
  Year 2006 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol  
  Volume 209 Issue Pt 15 Pages 3025-3042  
  Keywords Animals; Biomechanics; Bone and Bones/*physiology; Collagen/*physiology; Forelimb; Horses/*physiology  
  Abstract This study examined relative influences of predominant collagen fiber orientation (CFO), mineralization (% ash), and other microstructural characteristics on the mechanical properties of equine cortical bone. Using strain-mode-specific (S-M-S) testing (compression testing of bone habitually loaded in compression; tension testing of bone habitually loaded in tension), the relative mechanical importance of CFO and other material characteristics were examined in equine third metacarpals (MC3s). This model was chosen since it had a consistent non-uniform strain distribution estimated by finite element analysis (FEA) near mid-diaphysis of a thoroughbred horse, net tension in the dorsal/lateral cortices and net compression in the palmar/medial cortices. Bone specimens from regions habitually loaded in tension or compression were: (1) tested to failure in both axial compression and tension in order to contrast S-M-S vs non-S-M-S behavior, and (2) analyzed for CFO, % ash, porosity, fractional area of secondary osteonal bone, osteon cross-sectional area, and population densities of secondary osteons and osteocyte lacunae. Multivariate multiple regression analyses revealed that in S-M-S compression testing, CFO most strongly influenced total energy (pre-yield elastic energy plus post-yield plastic energy); in S-M-S tension testing CFO most strongly influenced post-yield energy and total energy. CFO was less important in explaining S-M-S elastic modulus, and yield and ultimate stress. Therefore, in S-M-S loading CFO appears to be important in influencing energy absorption, whereas the other characteristics have a more dominant influence in elastic modulus, pre-yield behavior and strength. These data generally support the hypothesis that differentially affecting S-M-S energy absorption may be an important consequence of regional histocompositional heterogeneity in the equine MC3. Data inconsistent with the hypothesis, including the lack of highly longitudinal collagen in the dorsal-lateral ;tension' region, paradoxical histologic organization in some locations, and lack of significantly improved S-M-S properties in some locations, might reflect the absence of a similar habitual strain distribution in all bones. An alternative strain distribution based on in vivo strain measurements, without FEA, on non-Thoroughbreds showing net compression along the dorsal-palmar axis might be more characteristic of the habitual loading of some of the bones that we examined. In turn, some inconsistencies might also reflect the complex torsion/bending loading regime that the MC3 sustains when the animal undergoes a variety of gaits and activities, which may be representative of only a portion of our animals, again reflecting the possibility that not all of the bones examined had similar habitual loading histories.  
  Address Utah Bone and Joint Center, 5323 S. Woodrow Street #202, Salt Lake City, UT 84107, USA. jskedros@utahboneandjoint.com  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0022-0949 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16857886 Approved no  
  Call Number Serial 1868  
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