Holt D, St George L B, Clayton H M, Hobbs S J
Department of Research, Myerscough College, Preston, UK.
Centre for Applied Sport and Exercise Sciences, University of Central Lancashire, Preston, UK.
Equine Vet J. 2017 Sep;49(5):688-691. doi: 10.1111/evj.12669. Epub 2017 Feb 28.
Previous studies have validated methods for determining kinematic gait events using threshold-based techniques. However, a simple method that can be successfully applied to walk, trot and canter is yet to be identified.
To develop a simple kinematic method to identify the timing of hoof contact (hoof-on), peak vertical force and lift off (hoof-off), which can be applied in walk, trot and canter.
In vivo method authentication study.
Horses (n = 3) were ridden in walk, trot and canter down a runway on which four force plates were arranged linearly. Three-dimensional forces were recorded at a sampling rate of 960 Hz and were synchronised with a 10-camera motion analysis system sampling at 120 Hz. Events identified from vertical ground reaction force (GRFz) data were hoof-on (GRFz>50N), peak vertical force (GRFz ) and hoof-off (GRFz<50N). Kinematic identification of hoof-on and hoof-off events was based on sagittal planar angles of the fore- and hindlimbs. Peak metacarpophalangeal (MCP)/metatarsophalangeal (MTP) joint extension was used to assess the time of GRFz . The accuracy (mean) and precision (s.d.) of time differences between kinetic and kinematic events were calculated for fore- and hindlimbs at each gait.
Hoof-off was determined with better accuracy (range: -3.94 to 8.33 ms) and precision (range: 5.43-11.39 ms) than hoof-on across all gaits. Peak MCP angle (range: 5.83-19.65 ms) was a more precise representation of GRFz than peak MTP angle (range: 11.49-67.75 ms).
The sample size was small and therefore further validation is required. The proposed method was tested on a single surface.
This study proposes a simple kinematic method of detecting hoof-on, hoof-off and GRFz at walk, trot and canter. Further work should focus on validating the methodology in a larger number of horses and should extend the method for use on surfaces with varying levels of compliance.
以往研究已验证了使用基于阈值的技术来确定运动步态事件的方法。然而，一种能够成功应用于行走、小跑和慢跑的简单方法尚未被发现。
开发一种简单的运动学方法，以识别蹄接触（蹄着地）、垂直力峰值和离地（蹄离地）的时间，该方法可应用于行走、小跑和慢跑。
体内方法验证研究。
让3匹马在一条直线排列有4个测力板的跑道上进行行走、小跑和慢跑。以960Hz的采样率记录三维力，并与以120Hz采样的10台摄像机运动分析系统同步。从垂直地面反作用力（GRFz）数据中识别出的事件为蹄着地（GRFz>50N）、垂直力峰值（GRFz ）和蹄离地（GRFz<50N）。蹄着地和蹄离地事件的运动学识别基于前后肢的矢状面角度。掌指（MCP）/跖趾（MTP）关节伸展峰值用于评估GRFz的时间。计算每个步态下前后肢动力学和运动学事件之间时间差的准确性（平均值）和精确性（标准差）。
在所有步态中，蹄离地的确定在准确性（范围：-3.94至8.33毫秒）和精确性（范围：5.43-11.39毫秒）方面均优于蹄着地。掌指关节峰值角度（范围：5.83-19.65毫秒）比跖趾关节峰值角度（范围：11.49-67.75毫秒）更能精确反映GRFz。
样本量小，因此需要进一步验证。所提出的方法仅在单一表面上进行了测试。
本研究提出了一种在行走、小跑和慢跑时检测蹄着地、蹄离地和GRFz的简单运动学方法。进一步的工作应集中于在更多马匹中验证该方法，并应扩展该方法以用于不同顺应性水平的表面。
