The Experts below are selected from a list of 22662 Experts worldwide ranked by ideXlab platform
Thrishantha Nanayakkara - One of the best experts on this subject based on the ideXlab platform.
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Significance of the Compliance of the Joints on the Dynamic Slip Resistance of a Bioinspired Hoof
IEEE Transactions on Robotics, 2019Co-Authors: Sara-adela Abad, Nicolas Herzig, Seyedmohammadhadi Hadi M. Sadati, Thrishantha NanayakkaraAbstract:Robust mechanisms for slip resistance are an open challenge in legged locomotion. Animals such as goats show impressive ability to resist slippage on cliffs. It is not fully known what attributes in their body determine this ability. Studying the slip resistance dynamics of the goat may offer insight toward the biologically inspired design of robotic Hooves. This article tests how the embodiment of the hoof contributes to solving the problem of slip resistance. We ran numerical simulations and experiments using a passive robotic goat hoof for different compliance levels of its three joints. We established that compliant yaw and pitch and stiff roll can increase the energy required to slide the hoof by $\approx \text{20}\%$ compared to the baseline (stiff hoof). Compliant roll and pitch allow the robotic hoof to adapt to the irregularities of the terrain. This produces an antilock braking system-like behavior of the robotic hoof for slip resistance. Therefore, the pastern and coffin joints have a substantial effect on the slip resistance of the robotic hoof, while the fetlock joint has the lowest contribution. These shed insights into how robotic Hooves can be used to autonomously improve slip resistance.
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Significance of the Compliance of the Joints on the Dynamic Slip Resistance of a Bioinspired Hoof
IEEE Transactions on Robotics, 2019Co-Authors: Sara-adela Abad, Nicolas Herzig, Seyedmohammadhadi Hadi M. Sadati, Thrishantha NanayakkaraAbstract:Robust mechanisms for slip resistance are an open challenge in legged locomotion. Animals such as goats show impressive ability to resist slippage on cliffs. It is not fully known what attributes in their body determine this ability. Studying the slip resistance dynamics of the goat may offer insight toward the biologically inspired design of robotic Hooves. This article tests how the embodiment of the hoof contributes to solving the problem of slip resistance. We ran numerical simulations and experiments using a passive robotic goat hoof for different compliance levels of its three joints. We established that compliant yaw and pitch and stiff roll can increase the energy required to slide the hoof by ≈ 20% compared to the baseline (stiff hoof). Compliant roll and pitch allow the robotic hoof to adapt to the irregularities of the terrain. This produces an antilock braking system-like behavior of the robotic hoof for slip resistance. Therefore, the pastern and coffin joints have a substantial effect on the slip resistance of the robotic hoof, while the fetlock joint has the lowest contribution. These shed insights into how robotic Hooves can be used to autonomously improve slip resistance.
G L Cloud - One of the best experts on this subject based on the ideXlab platform.
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a method for determination of equine hoof strain patterns using photoelasticity an in vitro study
Equine Veterinary Journal, 1999Co-Authors: Loïc M. Déjardin, Steven P. Arnoczky, G L CloudAbstract:Summary During impact, equine Hooves undergo viscoelastic deformations which may result in potentially harmful strains. Previous hoof strain studies using strain guages have been inconclusive due to arbitrary guage placement. Photoelastic stress analysis (PSA) is a full-field technique which visually displays strains over entire loaded surfaces. This in vitro study identifies normal hoof strain patterns using PSA. Custom-made photoelastic plastic sheets were applied to the hoof surface. The Hooves were axially loaded (225 kg) under level and varus/valgus conditions. Strain patterns were video-recorded through a polariscope. Strains were concentrated between middle and distal thirds of the hoof wall regardless of the loading conditions. This strain distribution appears to result from the differential expansion of the hoof wall under load. Increasing load resulted in higher strains and asymmetric loading resulted in an ipsilateral increase in strain magnitudes without altering strain locations. This study shows that PSA is a reliable method with which to evaluate hoof strains in vitro and is sensitive enough to reflect subtle load-related strain alterations.
Sara-adela Abad - One of the best experts on this subject based on the ideXlab platform.
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Significance of the Compliance of the Joints on the Dynamic Slip Resistance of a Bioinspired Hoof
IEEE Transactions on Robotics, 2019Co-Authors: Sara-adela Abad, Nicolas Herzig, Seyedmohammadhadi Hadi M. Sadati, Thrishantha NanayakkaraAbstract:Robust mechanisms for slip resistance are an open challenge in legged locomotion. Animals such as goats show impressive ability to resist slippage on cliffs. It is not fully known what attributes in their body determine this ability. Studying the slip resistance dynamics of the goat may offer insight toward the biologically inspired design of robotic Hooves. This article tests how the embodiment of the hoof contributes to solving the problem of slip resistance. We ran numerical simulations and experiments using a passive robotic goat hoof for different compliance levels of its three joints. We established that compliant yaw and pitch and stiff roll can increase the energy required to slide the hoof by $\approx \text{20}\%$ compared to the baseline (stiff hoof). Compliant roll and pitch allow the robotic hoof to adapt to the irregularities of the terrain. This produces an antilock braking system-like behavior of the robotic hoof for slip resistance. Therefore, the pastern and coffin joints have a substantial effect on the slip resistance of the robotic hoof, while the fetlock joint has the lowest contribution. These shed insights into how robotic Hooves can be used to autonomously improve slip resistance.
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Significance of the Compliance of the Joints on the Dynamic Slip Resistance of a Bioinspired Hoof
IEEE Transactions on Robotics, 2019Co-Authors: Sara-adela Abad, Nicolas Herzig, Seyedmohammadhadi Hadi M. Sadati, Thrishantha NanayakkaraAbstract:Robust mechanisms for slip resistance are an open challenge in legged locomotion. Animals such as goats show impressive ability to resist slippage on cliffs. It is not fully known what attributes in their body determine this ability. Studying the slip resistance dynamics of the goat may offer insight toward the biologically inspired design of robotic Hooves. This article tests how the embodiment of the hoof contributes to solving the problem of slip resistance. We ran numerical simulations and experiments using a passive robotic goat hoof for different compliance levels of its three joints. We established that compliant yaw and pitch and stiff roll can increase the energy required to slide the hoof by ≈ 20% compared to the baseline (stiff hoof). Compliant roll and pitch allow the robotic hoof to adapt to the irregularities of the terrain. This produces an antilock braking system-like behavior of the robotic hoof for slip resistance. Therefore, the pastern and coffin joints have a substantial effect on the slip resistance of the robotic hoof, while the fetlock joint has the lowest contribution. These shed insights into how robotic Hooves can be used to autonomously improve slip resistance.
Loïc M. Déjardin - One of the best experts on this subject based on the ideXlab platform.
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Photoelastic stress analysis of strain patterns in equine Hooves after four-point trimming
American journal of veterinary research, 2001Co-Authors: Loïc M. Déjardin, Steven P. Arnoczky, Gary L. Cloud, John A. StickAbstract:Objective—To evaluate changes in strain patterns in normal equine Hooves following 4-point trimming, using photoelastic stress analysis. Sample Population—15 equine front limbs with normal hoof configuration. Procedure—Limbs were disarticulated at the carpometacarpal joint. Weight-bearing surfaces of each hoof were trimmed level to ensure 100% ground contact. Hoof walls were coated with a custom-made strain-sensitive plastic, and limbs were loaded to a third of body weight. Using a polariscope, strain distribution, magnitudes, and directions were evaluated in level Hooves as well as before and after standardized 4-point trimming. Repeated-measures ANOVA was used to compare strain magnitudes and directions before and after trimming. Results—In leveled specimens, strain fields were symmetrically distributed above the heels and at quarter-toe junctions along a line between the middle and distal thirds of the hoof wall. After 4-point trimming, strain epicenters localized above the contact points, whereas stra...
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a method for determination of equine hoof strain patterns using photoelasticity an in vitro study
Equine Veterinary Journal, 1999Co-Authors: Loïc M. Déjardin, Steven P. Arnoczky, G L CloudAbstract:Summary During impact, equine Hooves undergo viscoelastic deformations which may result in potentially harmful strains. Previous hoof strain studies using strain guages have been inconclusive due to arbitrary guage placement. Photoelastic stress analysis (PSA) is a full-field technique which visually displays strains over entire loaded surfaces. This in vitro study identifies normal hoof strain patterns using PSA. Custom-made photoelastic plastic sheets were applied to the hoof surface. The Hooves were axially loaded (225 kg) under level and varus/valgus conditions. Strain patterns were video-recorded through a polariscope. Strains were concentrated between middle and distal thirds of the hoof wall regardless of the loading conditions. This strain distribution appears to result from the differential expansion of the hoof wall under load. Increasing load resulted in higher strains and asymmetric loading resulted in an ipsilateral increase in strain magnitudes without altering strain locations. This study shows that PSA is a reliable method with which to evaluate hoof strains in vitro and is sensitive enough to reflect subtle load-related strain alterations.
Susan M. Stover - One of the best experts on this subject based on the ideXlab platform.
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effect of hoof trimming on the occurrence of distal phalangeal palmar process fractures in foals
Equine Veterinary Journal, 2010Co-Authors: A J Kaneps, Neil H Willits, J E Dykes, T R Obrien, Susan M. StoverAbstract:Summary This study sought to determine if extensive trimming of the front Hooves of foals results in a higher incidence of palmar process fractures compared to untrimmed foals, and to characterise the clinical course of foals with palmar process fractures with physical findings, hoof measurements and radiography. Twenty foals age 4–8 weeks of multiple breeds were examined every 2 weeks over a 12 week period. Ten foals had both front Hooves extensively trimmed every 4 weeks, while 10 foals remained untrimmed. Palmar process fractures occurred in 4 trimmed and 3 untrimmed foals. Four foals with fractures had brief lameness (Grades I-II/V) and hoof tester sensitivity was found inconsistently with fractures. All foals with fractures were sound at the end of the study. Fractures healed based on radiographic evaluations in an average of 8.4 weeks. Two of 3 foals with fractures developed club-footed conformation. None of the measured hoof parameters significantly differed between foals with and without fractures. We conclude that extensive trimming of the heels did not appear to affect the occurrence of palmar process fractures in this group of foals.
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Geometric symmetry of the solar surface of Hooves of thoroughbred racehorses
American Journal of Veterinary Research, 2003Co-Authors: Elizabeth S. Roland, Susan M. Stover, Maury L. Hull, Katie DorschAbstract:Objective—To define a 3-dimensional (3-D) coordinate system with clear definitions of origins and axes relative to hoof anatomic features and determine whether solar surfaces of Thoroughbred racehorse Hooves have geometric asymmetry in the mediolateral and dorsopalmar directions. Sample Population—Left forelimb Hooves from 20 Thoroughbred racehorse cadavers. Procedure—A right-handed 3-D coordinate axes system centered on the collateral sulci was defined for the left front hoof. Orthogonal distances of anatomic features from the dorsopalmar axis and the plane coincident with the ground were measured and compared between medial and lateral sides and between dorsal and palmar regions of the hoof. Results—The hoof was wider and had a greater radius laterally than medially. The most distal part of the lateral bar of the frog was further from the dorsopalmar axis than that of the medial bar. Overall, mediolateral asymmetries in depth were not observed. The sole at the perimeter was deeper medially in the dorsal...
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Postmortem evaluation of homotypic variation in shoe characteristics of 201 Thoroughbred racehorses
American journal of veterinary research, 1996Co-Authors: Albert J. Kane, Susan M. Stover, Ian A. Gardner, James T. Case, Bill J. Johnson, Michael J. O'brien, Deryck H. Read, Alex ArdansAbstract:OBJECTIVES To develop a standard technique for evaluation of racehorse shoes, to assess homotypic variation (interlimb variation) in shoe characteristics, and to determine whether shoe characteristics varied with age and sex. DESIGN Cross-sectional study. ANIMALS Thoroughbred racehorses (n = 201) that died or were euthanatized at California racetracks between August 1992 and July 1994. PROCEDURE Shoe characteristics were measured on horses examined after death. Percentage of agreement was used to compare shoe characteristics between limbs (homotypic variation). Using chi 2 analysis, shoe characteristics were compared between horses grouped by age and sex. RESULTS Toe grabs were present on 90.5% of horses, and rim shoes were present on 15.9% of horses. Heel traction devices were less frequent on front (2.5%) than rear (6%) Hooves. Pads were present on 24.9% of horses, with bonded rim pads most common. Special types of shoes were present cn 5% of horses. Percentage of agreement between left and right front Hooves and between left and right rear Hooves was high (20/25 variables; % agreement > or = 99). In contrast, percentage of agreement between left front and left rear Hooves and between right front and right rear Hooves was low (2/25 variables; % agreement > or = 99). Presence of a pad was significantly (P < 0.05) associated with age, and several shoe variable (size, presence of a special shoe, overall wear matched) were significantly (P < 0.05) associated with sex. CLINICAL RELEVANCE Except for variables related to special shoes, wear, and weight, 1 shoe for the respective fore- or hind limbs could be used as an indicator for the contralateral shoe worn by Thoroughbred racehorses without substantial loss of information. However, 1 shoe could not be used as an indicator for shoe characteristics of all 4 limbs. Some shoe characteristics are associated with age and sex, and these variables should be considered possible confounders in studies of shoe characteristics.