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Author Bobbert, M.F.; Alvarez, C.B.G.; van Weeren, P.R.; Roepstorff, L.; Weishaupt, M.A. doi  openurl
  Title Validation of vertical ground reaction forces on individual limbs calculated from kinematics of horse locomotion Type Journal Article
  Year (up) 2007 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol  
  Volume 210 Issue Pt 11 Pages 1885-1896  
  Keywords  
  Abstract The purpose of this study was to determine whether individual limb forces could be calculated accurately from kinematics of trotting and walking horses. We collected kinematic data and measured vertical ground reaction forces on the individual limbs of seven Warmblood dressage horses, trotting at 3.4 m s(-1) and walking at 1.6 m s(-1) on a treadmill. First, using a segmental model, we calculated from kinematics the total ground reaction force vector and its moment arm relative to each of the hoofs. Second, for phases in which the body was supported by only two limbs, we calculated the individual reaction forces on these limbs. Third, we assumed that the distal limbs operated as linear springs, and determined their force-length relationships using calculated individual limb forces at trot. Finally, we calculated individual limb force-time histories from distal limb lengths. A good correspondence was obtained between calculated and measured individual limb forces. At trot, the average peak vertical reaction force on the forelimb was calculated to be 11.5+/-0.9 N kg(-1) and measured to be 11.7+/-0.9 N kg(-1), and for the hindlimb these values were 9.8+/-0.7 N kg(-1) and 10.0+/-0.6 N kg(-1), respectively. At walk, the average peak vertical reaction force on the forelimb was calculated to be 6.9+/-0.5 N kg(-1) and measured to be 7.1+/-0.3 N kg(-1), and for the hindlimb these values were 4.8+/-0.5 N kg(-1) and 4.7+/-0.3 N kg(-1), respectively. It was concluded that the proposed method of calculating individual limb reaction forces is sufficiently accurate to detect changes in loading reported in the literature for mild to moderate lameness at trot.  
  Address Institute for Fundamental and Clinical Human Movement Sciences, Vrije Universiteit, van der Boechorstraat 9, NL-1081 BT Amsterdam, The Netherlands  
  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 0022-0949 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17515415 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3700  
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Author Brinkmann, L.; Gerken, M.; Hambly, C.; Speakman, J.R.; Riek, A. url  doi
openurl 
  Title Saving energy during hard times: Energetic adaptations of Shetland pony mares Type Journal Article
  Year (up) 2014 Publication The Journal of Experimental Biology Abbreviated Journal J. Exp. Biol.  
  Volume 217 Issue Pages 4320-4327  
  Keywords  
  Abstract Recent results suggest that wild Northern herbivores reduce their metabolism during times of low ambient temperatures and food shortage in order to reduce their energetic needs. It is however not known if domesticated animals are also able to reduce their energy expenditure. We exposed ten Shetland pony mares to different environmental conditions (summer and winter) and to two food quantities (60 and 100% of maintenance energy requirement, respectively) during low winter temperatures to examine energetic and behavioural responses. In summer ponies showed a considerably higher field metabolic rate (FMR) (63.4±15.0 MJ d-1) compared to restrictively fed and control animals in winter (24.6±7.8 MJ d-1 and 15.0±1.1 MJ d-1, respectively). During summer conditions locomotor activity, resting heart rates and total water turnover were considerably elevated (P<0.001) compared to winter. Restrictively fed animals (N=5) compensated for the decreased energy supply by reducing their FMR by 26% compared to control animals (N=5). Furthermore, resting heart rate, body mass and body condition score were lower (29.2±2.7 beats min-1; 140±22 kg; 3.0±1.0 points) than in control animals (36.8±41 beats min-1; 165 ±31 kg; 4.4±0.7 points; P<0.05). While the observed behaviour did not change, nocturnal hypothermia was elevated. We conclude that ponies acclimatize to different climatic conditions by changing their metabolic rate, behaviour and some physiological parameters. When exposed to energy challenges, ponies, like wild herbivores, exhibited hypometabolism and nocturnal hypothermia.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
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  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes 10.1242/jeb.111815 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5836  
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