Effects of egg-bar shoes on the 3-dimensional kinematics of the distal forelimb in horses walking on a sand track.
BACKGROUND
Understanding of the biomechanical effects of egg-bar shoes remains incomplete because kinematic studies are usually performed on hard tracks and with skin markers that do not measure the actual 3-dimensional (3D) movements of the 3 digital joints.


OBJECTIVE
To quantify the effects of egg-bar shoes on the 3D kinematics of the distal forelimb in horses walking on a sand track.


METHODS
Four healthy horses were equipped with ultrasonic markers fixed surgically to the 4 distal segments of the left forelimb. The 3D movements of these segments were recorded while the horses were walking on a sand track. Rotations of the digital joints were calculated by use of a joint coordinate system. Data obtained with egg-bar shoes were compared to those obtained with standard shoes. Mean differences were expressed in a 0.95 confidence interval.


RESULTS
With egg-bar shoes, the initial sinking of the heels into the ground during landing was reduced and the heels were raised by up to 5.1 degrees (3.5-6.7 degrees) compared to standard shoes at mid-stance. Concurrently, maximal flexion of the distal (DIPJ) and proximal (PIPJ) interphalangeal joints was increased by up to 3.2 degrees (2.2-4.2 degrees) and 1.8 degrees (1.1-2.5 degrees), respectively, at the beginning of the stance phase. At heel-off, extension of the DIPJ was reduced by 3.8 degrees (2.6-5.0 degrees). In extrasagittal planes of movement, egg-bar shoes prevented sinking of the medial quarter into the ground which led to a slight decrease of DIPJ medial rotation and lateromotion.


CONCLUSIONS
Egg-bar shoes prevent the heels and, to a lesser extent, the medial side of the hoof from sinking into the ground on a sand track. They contribute to a decrease of DIPJ maximal extension at heel-off and to hoof stabilisation in the transversal plane.


CONCLUSIONS
Such quantitative results support the clinical indications of egg-bar shoes.
Chateau
H
H
UMR INRA-ENVA de Biomécanique et Pathologie Locomotrice du Cheval, Ecole Nationale Vétérinaire d'Alfort, 7, Avenue du Géneral du Gaulle, 94704 Maisons-Alfort, France.
Degueurce
C
C
Denoix
J M
JM
D000818:Animals; D001696:Biomechanical Phenomena; D005552:Forelimb / Q000000981:diagnostic imaging / Q000502:physiology*; D006724:Hoof and Claw / Q000000981:diagnostic imaging / Q000502:physiology*; D006736:Horses / Q000502:physiology*; D021621:Imaging, Three-Dimensional / Q000662:veterinary*; D012399:Rotation; D012822:Silicon Dioxide; D014033:Toe Joint / Q000000981:diagnostic imaging / Q000502:physiology*; D014463:Ultrasonography; D016138:Walking / Q000502:physiology*
D012822:Silicon Dioxide