KINEMATICS OF TREADMILL VERSUS OVERGROUND LOCOMOTION IN HORSES

A kinematic analysis was carried out to compare treadmill and overgrou nd locomotion in horses at the trot. Stride variables and limb and tru nk movements of 10 Dutch Warmblood horses were measured using the CODA -3 gait analysis system. Overground recordings were made on a rubber g round surface and on an asphalt track. Treadmill recordings were taken after a controlled habituation programme and at the same velocities a s measured overground. On asphalt, a shorthened stride duration and a decreased vertical displacement of the withers were found compared wit h those on rubber ground. On the treadmill, stance duration of the for elimbs was longer than for either overground condition. Correspondingl y, the hind limbs were placed earlier than the forelimbs in making dia gonal ground contact in overground locomotion, but this changed to pre ceding forelimbs on the treadmill. Both forelimbs and hind limbs were moved more caudally during the retraction phase on the treadmill, whil e no differences were found in the protraction angle. The vertical mov ement of the hooves as well as the withers was smaller on the treadmil l than on rubber ground. Treadmill belt velocity decreased by 9 % duri ng the stance phase. This is supposed to be an important reason for th e differences in biomechanics and kinematics between treadmill and ove rground locomotion, which must be kept in mind when data obtained duri ng treadmill locomotion have to be extrapolated to overground conditio ns.