Clayton H M, Sha D, Stick J, Elvin N
Mary Anne McPhail Equine Performance Center, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, 48824-1314 USA.
Vet Comp Orthop Traumatol. 2007;20(2):86-91. doi: 10.1160/vcot-07-01-0011.
The metacarpophalangeal (MCP) joint and its supporting soft tissues are common sites of injury in athletic horses. Equine gait analysis has focused on 2D analysis in the sagittal plane and little information is available which describes 3D motions of the MCP joint and their possible role in the development of injuries. The aim was to characterize the 3D rotations of the equine MCP joint during walking and trotting. Three-dimensional trajectories of marker triads fixed rigidly to the third metacarpus and proximal phalanx of the right forelimb of healthy horses were recorded at walk (n = 4) and trot (n = 6) at 120 Hz using eight infra-red cameras. Kinematics of the MCP joint were calculated in terms of helical angles between the two segments using singular-value decomposition and spatial attitude methods. The ranges of motion were: flexion/extension: 62 +/- 7 degrees at walk, 77 +/- 5 degrees at trot; adduction/abduction: 13 +/- 7 degrees at walk, 18 +/- 7 degrees at trot; and axial rotation: 6 +/- 3 degrees at walk, 9 +/- 5 degrees at trot. Flexion/extension had a consistent pattern and amplitude in all horses and appeared to be coupled with adduction/abduction, such that stance phase extension was accompanied by abduction and swing phase flexion was accompanied by adduction. Axial rotation was small in amount and the direction varied between horses but was consistent within an individual for the two gaits.
掌指（MCP）关节及其支持性软组织是运动马匹常见的损伤部位。马的步态分析主要集中在矢状面的二维分析上，而关于MCP关节三维运动及其在损伤发展中可能作用的信息很少。目的是描述马在行走和小跑时MCP关节的三维旋转情况。使用八个红外摄像机，以120Hz的频率记录了健康马匹右前肢第三掌骨和近端指骨上刚性固定的标记三联体在行走（n = 4）和小跑（n = 6）时的三维轨迹。使用奇异值分解和空间姿态方法，根据两段之间的螺旋角计算MCP关节的运动学。运动范围为：屈伸：行走时62±7度，小跑时77±5度；内收/外展：行走时13±7度，小跑时18±7度；轴向旋转：行走时6±3度，小跑时9±5度。屈伸在所有马匹中具有一致的模式和幅度，并且似乎与内收/外展相关联，使得站立期伸展伴随着外展，摆动期屈曲伴随着内收。轴向旋转量小，方向在马匹之间有所不同，但在个体内的两种步态中是一致的。
