Ramadan Ahmed, Cholewicki Jacek, Radcliffe Clark J, Popovich John M, Reeves N Peter, Choi Jongeun
Department of Mechanical Engineering, College of Engineering, Michigan State University, East Lansing, MI, USA; MSU Center for Orthopedic Research, College of Osteopathic Medicine, Michigan State University, Lansing, MI, USA.
MSU Center for Orthopedic Research, College of Osteopathic Medicine, Michigan State University, Lansing, MI, USA; Department of Osteopathic Surgical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA.
J Biomech. 2017 Nov 7;64:198-205. doi: 10.1016/j.jbiomech.2017.09.036. Epub 2017 Oct 7.
This study evaluated the within- and between-visit reliability of a seated balance test for quantifying trunk motor control using input-output data. Thirty healthy subjects performed a seated balance test under three conditions: eyes open (EO), eyes closed (EC), and eyes closed with vibration to the lumbar muscles (VIB). Each subject performed three trials of each condition on three different visits. The seated balance test utilized a torque-controlled robotic seat, which together with a sitting subject resulted in a physical human-robot interaction (pHRI) (two degrees-of-freedom with upper and lower body rotations). Subjects balanced the pHRI by controlling trunk rotation in response to pseudorandom torque perturbations applied to the seat in the coronal plane. Performance error was expressed as the root mean square (RMSE) of deviations from the upright position in the time domain and as the mean bandpass signal energy (E) in the frequency domain. Intra-class correlation coefficients (ICC) quantified the between-visit reliability of both RMSE and E. The empirical transfer function estimates (ETFE) from the perturbation input to each of the two rotational outputs were calculated. Coefficients of multiple correlation (CMC) quantified the within- and between-visit reliability of the averaged ETFE. ICCs of RMSE and E for all conditions were ≥0.84. The mean within- and between-visit CMCs were all ≥0.96 for the lower body rotation and ≥0.89 for the upper body rotation. Therefore, our seated balance test consisting of pHRI to assess coronal plane trunk motor control is reliable.
本研究使用输入-输出数据评估了一种用于量化躯干运动控制的坐位平衡测试在不同测试间及测试内的可靠性。30名健康受试者在三种条件下进行坐位平衡测试：睁眼（EO）、闭眼（EC）以及对腰部肌肉施加振动的闭眼状态（VIB）。每位受试者在三次不同的测试中，对每种条件各进行三次试验。坐位平衡测试采用了扭矩控制的机器人座椅，该座椅与就座的受试者共同构成了一种人机物理交互（pHRI）（具有上下身旋转的两个自由度）。受试者通过控制躯干旋转来平衡pHRI，以响应在冠状面施加于座椅的伪随机扭矩扰动。性能误差在时域中表示为相对于直立位置偏差的均方根（RMSE），在频域中表示为平均带通信号能量（E）。组内相关系数（ICC）量化了RMSE和E在不同测试间的可靠性。计算了从扰动输入到两个旋转输出各自的经验传递函数估计值（ETFE）。多重相关系数（CMC）量化了平均ETFE在测试内和测试间的可靠性。所有条件下RMSE和E的ICC均≥0.84。下身旋转的测试内和测试间平均CMC均≥0.96，上身旋转的平均CMC≥0.89。因此，我们由pHRI组成的用于评估冠状面躯干运动控制的坐位平衡测试是可靠的。
