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Author Powers, P.; Harrison, A. openurl 
  Title Effects of the rider on the linear kinematics of jumping horses Type Journal Article
  Year 2002 Publication Sports Biomechanics / International Society of Biomechanics in Sports Abbreviated Journal Sports Biomech  
  Volume 1 Issue 2 Pages 135-146  
  Keywords Animals; Behavior, Animal/*physiology; Biomechanics; Communication; Exertion/*physiology; Gait/*physiology; Horses/*physiology; Humans; Locomotion/*physiology; Posture/*physiology; Task Performance and Analysis; Video Recording; Weight-Bearing/*physiology  
  Abstract This study examined the effects of the rider on the linear projectile kinematics of show-jumping horses. SVHS video recordings (50 Hz) of eight horses jumping a vertical fence 1 m high were used for the study. Horses jumped the fence under two conditions: loose (no rider or tack) and ridden. Recordings were digitised using Peak Motus. After digitising the sequences, each rider's digitised data were removed from the ridden horse data so that three conditions were examined: loose, ridden (including the rider's data) and riderless (rider's data removed). Repeated measures ANOVA revealed significant differences between ridden and loose conditions for CG height at take-off (p < 0.001), CG distance to the fence at take-off (p = 0.001), maximum CG during the suspension phase (p < 0.001), CG position over the centre of the fence (p < 0.001), CG height at landing (p < 0.001), and vertical velocity at take-off (p < 0.001). The results indicated that the rider's effect on jumping horses was primarily due to behavioural changes in the horses motion (resulting from the rider's instruction), rather than inertial effects (due to the positioning of the rider on the horse). These findings have implications for the coaching of riders and horses.  
  Address Department of PE and Sports Sciences, University of Limerick, Limerick, Ireland  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1476-3141 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:14658371 Approved no  
  Call Number Serial 1904  
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Author Davies, H.M.S. openurl 
  Title The timing and distribution of strains around the surface of the midshaft of the third metacarpal bone during treadmill exercise in one Thoroughbred racehorse Type Journal Article
  Year 2005 Publication Australian Veterinary Journal Abbreviated Journal Aust Vet J  
  Volume 83 Issue 3 Pages 157-162  
  Keywords Animals; Exercise Test/veterinary; Female; Gait/*physiology; Horses/*physiology; Metacarpus/*physiology; Motor Activity/physiology; Physical Conditioning, Animal/*physiology; Stress, Mechanical; Weight-Bearing/physiology  
  Abstract OBJECTIVE: To confirm that the midshaft dorsal cortex of the third metacarpal bone experienced higher compressive strains during fast exercise than the medial or lateral cortices, and that the strain peak occurred earlier in the hoof-down phase of the stride on the dorsal cortex than the medial or lateral cortices. DESIGN: Observations of a single horse. PROCEDURE: Strains were collected from a single, sound, 3-year-old Thoroughbred mare during treadmill exercise from rosette strain gauges implanted onto the medial, lateral and dorsal surfaces of the midshaft of the right cannon bone, simultaneously with data from a hoof switch that showed when the hoof was in the stance phase. RESULTS: Peak compressive strains on the dorsal surface of the third metacarpal bone were proportional to exercise speed and occurred at about 30% of stance. Peak compressive strains on the medial surface of the non-lead limb reached a maximum at a speed around 10 m/s and occurred at mid-stance. Peak compressive strains on the lateral surface varied in timing and size between strides at all exercise speeds, but remained less than -2000 microstrains. CONCLUSIONS: The timing of peak compressive strains on the dorsal cortex suggests a relationship to deceleration of the limb following hoof impact, so the main determinants of their size would be exercise speed and turning (as shown in previous experiments). This experiment confirms data from other laboratories that were published but not discussed, that peak compressive strains on the medial surface occur at mid-stance. This suggests that they are related to the support of body weight. The strains on the lateral cortex occurred at variable times so may be associated with the maintenance of balance as well as the support of body weight. Understanding the loading of the third metacarpal bone will help to determine causes of damage to it and ways in which the bone might be conditioned to prevent such damage.  
  Address Department of Veterinary Science, University of Melbourne, Parkville, Victoria 3010. h.davies@unimelb.edu.au  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0005-0423 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15825628 Approved no  
  Call Number Serial 1891  
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