床反力による馬の運動解析

2. 常歩, 速歩時の垂直, 前後分力波形と馬体動作との関連性

抄録

An experiment was carried out to define the normal force plate pattern in the horse as a basis for comparison with future studies on abnormal locomotion. The vertical and fore-aft components of the floor reaction forces and 16mm motion pictures taken during walking and trotting at different speeds were recorded in three normal horses and analyzed in relation to the locomotion speed. The floor reaction forces were measured by Kistler's force plate. A 16mm cine film was synchronized with the records of floor reaction forces to investigate the relationship between changes in the vertical and fore-aft components of the floor reaction forces and the movements of the limbs. The walking pattern of the vertical components exhibited almost two peaks during the stance phase in both fore and hind limbs. It varied slightly in accordance with the walking speed. In general, the faster speed, the more distinct the peaks and trough, which changed mainly the magnitude of the second peak in forelimb and the magnitude of the first peak and the trough between two peaks in the hind limb. The trotting pattern of the vertical components presented almost only one peak during the stance phase in both fore and hind limbs, regardless of the trotting speed. From the observation of the 16mm motion pictures, these differences between walk and trot might have been caused by displacement of the center of gravity of the body during the stance phase. The fore-aft components demonstrated essentially the same patterns, in spite of the difference in gaits and locomotive speed.