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Author Bobbert, M.F.; Alvarez, C.B.G.; van Weeren, P.R.; Roepstorff, L.; Weishaupt, M.A.
Title Validation of vertical ground reaction forces on individual limbs calculated from kinematics of horse locomotion Type Journal Article
Year 2007 Publication The Journal of Experimental Biology Abbreviated Journal (down) 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
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Language English Summary Language Original Title
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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 Kuntz, R.; Kubalek, C.; Ruf, T.; Tataruch, F.; Arnold, W.
Title Seasonal adjustment of energy budget in a large wild mammal, the Przewalski horse (Equus ferus przewalskii) I. Energy intake Type Journal Article
Year 2006 Publication The Journal of experimental biology Abbreviated Journal (down) J Exp Biol
Volume 209 Issue 22 Pages 4557-4565
Keywords
Abstract Large ruminants respond to changing plant phenology during winter by decreasing voluntary food intake, increasing gut passage time and utilizing body fat reserves. It is uncertain, however, how other large mammals with a non-ruminant digestive physiology cope with winter forage conditions. Therefore, we investigated seasonality of energy intake in a large herbivorous wild mammal, the Przewalski horse (Equus ferus przewalskii). Throughout all seasons we used the n-alkane method to measure daily dry matter intake (DMI), diet composition and digestion, and determined an index of gut passage time in horses living under close to natural conditions. DMI correlated positively with its content of crude protein and nitrogen-free extract. Independent of these effects, DMI further varied seasonally with a peak in autumn and a nadir in late winter. Fluctuations of DMI corresponded to the annual change in body condition, which decreased during winter while energy reserves were depleted, and increased during the fattening period. Gut passage time varied in the course of the year and was longer during winter when the diet was high in crude fibre. Nevertheless, changes in gut passage time occurred rather independently of changes in forage composition and DMI, suggesting endogenous control for timely adaption of the digestive strategy to meet predictable changes in forage quality.
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.02535 Approved no
Call Number Equine Behaviour @ team @ Serial 4729
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