Effects of 6 degree elevation of the heels on 3D kinematics of the distal portion of the forelimb in the walking horse.
BACKGROUND
Understanding of the biomechanical effects of heel elevation remains incomplete because in vivo studies performed with skin markers do not measure the actual movements of the 3 digital joints.


OBJECTIVE
To quantify the effects of 6 degree heel wedge on the 3-dimensional movements of the 4 distal segments of the forelimb in the walking horse.


METHODS
Four healthy horses were used. Kinematics of the distal segments was measured invasively with a system based on ultrasonic triangulation. Three-dimensional rotations of the digital joints were calculated by use of a 'joint coordinate system' (JCS). Data obtained with heel wedges were compared to those obtained with standard shoes during the stance phase of the stride.


RESULTS
Heel wedges significantly increased maximal flexion of the proximal (PIPJ) and distal (DIPJ) interphalangeal joints and maximal extension (mean +/- s.d. +0.8 +/- 0.3 degrees) of the metacarpophalangeal joint (MPJ). Extension of the PIPJ and DIPJ was decreased at heel-off. Few effects were observed in extrasagittal planes of movement.


CONCLUSIONS
Heel wedges affect the sagittal plane kinematics of the 3 digital joints.


CONCLUSIONS
Controversial effects previously observed on the MPJ may be explained by the substantial involvement of the PIPJ, which was wrongly neglected in previous studies performed on the moving horse.
Chateau
H
H
UMR INRA-ENVA de Biomécanique et Pathologie Locomotrice du Cheval, Ecole Nationale Vétérinaire d'Alfort, 7, Avenue du Général de 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; D008297:Male; D012399:Rotation; D014033:Toe Joint / Q000000981:diagnostic imaging / Q000502:physiology*; D014463:Ultrasonography; D016138:Walking / Q000502:physiology*