Speedtsberg Merete B, Christensen Sofie B, Stenum Jan, Kallemose Thomas, Bencke Jesper, Curtis Derek J, Jensen Bente R
Laboratory of Human Movement Analysis, Department of Orthopaedic Surgery, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark; Biomechanics and Motor Control Lab., Integrated Physiology, Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark.
Biomechanics and Motor Control Lab., Integrated Physiology, Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark.
Gait Posture. 2018 Jan;59:99-103. doi: 10.1016/j.gaitpost.2017.09.035. Epub 2017 Oct 5.
Developmental coordination disorder (DCD) is an innate impairment of motor coordination that affects basic locomotion and balance. This study investigated local dynamic stability of trunk accelerations during treadmill walking as an objective evaluation of gait stability and the sensitivity and specificity of this measure to discriminate children with DCD from typically developing children.
Eight children with DCD and ten age- and gender-matched typically developing children (TD) walked four minutes on a treadmill. Trunk accelerations in vertical, medio-lateral and anterior-posterior directions were recorded with a sternum mounted accelerometer at 256Hz. Short term local dynamic stability (λs), root mean square (RMS) and relative root mean square (RMSR) were calculated from measures of orthogonal trunk accelerations. Receiver operating characteristic curve (ROC) analysis was performed to discriminate between groups based on short term local dynamic stability.
λs was significantly greater in children with DCD in the main movement direction (AP) (DCD: 1.69±0.17 λs; TD:1.41±0.17 λs; p=0.005), indicating reduced local dynamic stability. RMS and RMSR accelerations showed no difference between children with DCD and TD children in any direction. The ROC analysis of λs in separate directions and in two dimensions showed an excellent accuracy of discriminating between children with DCD and TD children. Anterior-posterior direction in combination with medio-lateral or vertical showed best performance with an area under the curve (AUC) of 0.91.
We have shown that children with developmental coordination disorder have general reduced local dynamic stability and that the short term Lyapunov exponent has good power of discrimination between DCD and TD.
发育性协调障碍（DCD）是一种影响基本运动和平衡的先天性运动协调障碍。本研究调查了跑步机行走过程中躯干加速度的局部动态稳定性，以此作为步态稳定性的客观评估，以及该测量方法区分DCD儿童与正常发育儿童的敏感性和特异性。
8名DCD儿童和10名年龄及性别匹配的正常发育儿童（TD）在跑步机上行走4分钟。使用安装在胸骨上的加速度计以256Hz记录垂直、中外侧和前后方向的躯干加速度。根据正交躯干加速度测量值计算短期局部动态稳定性（λs）、均方根（RMS）和相对均方根（RMSR）。进行受试者工作特征曲线（ROC）分析，以基于短期局部动态稳定性区分两组。
DCD儿童在主要运动方向（前后方向）的λs显著更高（DCD：1.69±0.17 λs；TD：1.41±0.17 λs；p = 0.005），表明局部动态稳定性降低。DCD儿童和TD儿童在任何方向上的RMS和RMSR加速度均无差异。对λs在不同方向和二维的ROC分析显示，区分DCD儿童和TD儿童的准确性极佳。前后方向与中外侧或垂直方向相结合表现最佳，曲线下面积（AUC）为0.91。
我们已经表明，发育性协调障碍儿童的局部动态稳定性普遍降低，并且短期李雅普诺夫指数在区分DCD和TD方面具有良好的辨别力。
