Analysis and decomposition of accelerometric signals of trunk and thigh obtained during the sit-to-stand movement
Analysis and decomposition of accelerometric signals of trunk and thigh obtained during the sit-to-stand movement
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DOI：
10.1007/bf02345965
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发表时间：
2005-03-01
影响因子：
3.2
通讯作者：
Stam, HJ
中科院分区：
文献类型：
--
作者：
Janssen, WGM;Bussmann, JBJ;Stam, HJ
压阻式加速度计信号经常用于运动分析。然而，由于信号由不同的加速度分量组成，这使得它们的使用和解释变得复杂。这项研究的目的是深入了解在四种不同的坐立(STS)动作(自选、慢速、快速和全屈)中躯干和大腿部分的加速度计信号的成分。9名受试者对每种类型的STS运动进行了至少6次试验。利用从光电设备获得的运动学数据，对躯干和大腿在矢状方向上的加速度计信号进行分解。将每个加速度信号分解为重力分量和惯性分量，然后将躯干的惯性分量分解为转动分量和平移分量。加速度计信号可以可靠地重建：平均归一化均方根(RMS)躯干：6.5%(范围3-12%)，平均RMS大腿：3%(范围2-5%)。加速度信号具有很强的特征性和重复性。惯性分量的影响是显著的，特别是对加速度计信号中躯干最大屈曲的具体事件的时间影响更大。惯性的影响在躯干信号中比在大腿信号中大，并且随着速度的提高而增加。这项研究提供了对加速度信号、其分量以及STS运动类型的影响的洞察，并支持其在STS运动分析中的应用。
Piezoresistive accelerometer signals are frequently used in movement analysis. However, their use and interpretation are complicated by the fact that the signal is composed of different acceleration components. The aim of the study was to obtain insight into the components of accelerometer signals from the trunk and thigh segments during four different sit-to-stand (STS) movements (self-selected, slow, fast and fullflexion). Nine subjects performed at least six trials of each type of STS movement. Accelerometer signals from the trunk and thigh in the sagittal direction were decomposed using kinematic data obtained from an opto-electronic device. Each acceleration signal was decomposed into gravitational and inertial components, and the inertial component of the trunk was subsequently decomposed into rotational and translational components. The accelerometer signals could be reliably reconstructed: mean normalised root mean square (RMS) trunk: 6.5% (range 3-12%), mean RMS thigh: 3% (range 2-5%). The accelerometric signals were highly characteristic and repeatable. The influence of the inertial component was significant, especially on the timing of the specific event of maximum trunk flexion in the accelerometer signal. The effect of inertia was larger in the trunk signal than in the thigh signal and increased with higher speeds. The study provides insight into the acceleration signal, its components and the influence of the type of STS movement and supports its use in STS movement analysis.