Influence of individual competition level on back kinematics of horses jumping a vertical fence.
BACKGROUND
The costs and investments required for the purchase and training of showjumpers justify the need to find selection means for jumping horses. Use of objective kinematic criteria correlated to jumping ability could be helpful for this assessment.


OBJECTIVE
To compare back kinematics between 2 groups of horses of different competition levels (Group 1, competing at high level; Group 2 competing at low level) while free jumping over a 1 m vertical fence.


METHODS
Three-dimensional recordings were performed using 2 panning cameras. Kinematic parameters of the withers and tuber sacrale (vertical displacement, vertical and horizontal velocities), backline inclination and flexion-extension motion of the 3 main dorsal segments (thoracic, thoracolumbar and lumbosacral) were analysed.


RESULTS
Group 2 horses had a lower displacement of their withers and tuber sacrale from the end of the last approach stride until the first departure stride (P<0.05). As a result, they increased the flexion of their thoracolumbar and lumbosacral junctions during the hindlimb swing phase before take-off (P<0.05). However, withers and tuber sacrale velocities were slightly modified. Group 1 horses pitched their backline less forward during the forelimb stance phase before take-off and straightened it more after landing (P<0.05), probably indicating a more efficient strutting action of their forelimbs.


CONCLUSIONS
Because significant differences in back motion were found between good and poor jumpers when jumping a 1 m high fence, criteria based on certain back kinematics can be developed that may help in the selection of talented showjumpers.
Cassiat
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G
UMR INRA-ENVA de Biomécanique et Pathologie Locomotrice du Cheval, Ecole Nationale Vétérinaire d'Alfort, Avenue du Général de Gaulle, 94704 Maisons Alfort, France.
Pourcelot
P
P
Tavernier
L
L
Geiger
D
D
Denoix
J M
JM
Degueurce
D
D
D000818:Animals; D001415:Back / Q000502:physiology*; D001696:Biomechanical Phenomena; D005260:Female; D005552:Forelimb / Q000502:physiology*; D005684:Gait / Q000502:physiology*; D006614:Hindlimb / Q000502:physiology*; D006736:Horses / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000662:veterinary; D008124:Locomotion / Q000502:physiology; D008297:Male; D014741:Video Recording