Inter- and intra-limb coordination in arm tremor
Inter- and intra-limb coordination in arm tremor
复制标题
手臂震颤的肢体间和肢体内协调
作者：
S. Morrison;K. Newell
使用加速度计技术，在有视觉和无视觉条件下检查了成年受试者手臂震颤的肢体间和肢体内协调。加速度计数据进行了分析，使用标准的时域和频域分析和加速度时间序列的规律性，确定使用近似熵（Ap En）的措施。数据分析的结构，以检查的假设，有一个功能补偿之间的关系，在手臂协调姿势指向任务的肢体段的运动（震颤）。结果表明，在单臂内，加速度水平在近端到远端方向上增加，并且在同源臂节段之间是对称的。频率分析显示了姿势性震颤任务中每个肢体段的已建立的功率谱曲线，但手指运动包括（超出正常的8-12 Hz和20 Hz震颤）第三个较慢的峰值，在2-3 Hz左右，可能是由于其他手臂连杆的反作用力。视力对肢体段加速度的水平或频率模式没有影响。协调分析表明，有没有在执行这个姿势任务的时间或频率域的武器之间的联系。这一结果表明，正常震颤背后的神经元指令不是来自中枢神经系统内的共同中枢振荡器，而是以平行的方式组织起来的。肢体内协调的耦合强度根据特定的相邻肢体链接而变化。上臂与前臂、手与手指的加速度信号在时域上具有显著相关性，在频域上具有显著相干性。这些相应段对中的每一个内的臂单元的相位滞后接近于同相或0度。频率域中的显著相干性在上臂和手部运动之间也是明显的，这些段之间的相位滞后接近180度异相。对加速度信号的Ap En分析表明，上臂和手部加速度计信号比前臂和手指信号更有规律性。研究结果表明，在一个双肢姿势指向任务的手臂链接的肢体内协调的影响，组织的行动的腕关节和肩关节的补偿协同作用。这种补偿协同作用将4个肢体内自由度（手臂连杆）的协调降低为实际上的单个自由度手臂控制任务，该任务在组织上不与另一肢体或躯干的运动耦合。有人建议，这种协调解决方案减少了独立调节的自由度，以实现任务目标，但保留独立的身体部分控制的关键自由度的潜在适应姿势扰动。
Inter- and intra-limb coordination in arm tremor was examined in adult subjects under vision and no vision conditions using accelerometery techniques. The accelerometer data were analyzed using standard time and frequency domain analyses and the regularity of the acceleration time series was determined using an approximate entropy (Ap En) measure. The data analysis was structured to examine the hypothesis that there is a functional compensatory relation between the motion (tremor) of the limb segments in the arm coordination postural pointing task. The results showed that the level of acceleration increased in a proximal to distal direction within a single arm and was symmetrical across homologous arm segments. The frequency analysis showed the established power spectral profiles for each limb segment in postural tremor tasks, but the finger motion included (beyond the normal 8–12 Hz and 20 Hz tremor) a third slower peak at around 2–3 Hz, due possibly to the reactive forces of the other arm links. There was no effect of vision on the level or frequency patterns of acceleration in the limb segments. The coordination analysis showed that there was no linkage between the arms in either the time or frequency domain in the execution of this postural task. This result would tend to suggest that the neuronal commands underlying normal tremor are not derived from a common central oscillator within the central nervous system but are organized in a parallel fashion. The strength of the coupling of intra-limb coordination varied according to the particular adjacent limb links. There were significant correlations in the time domain and coherence in the frequency domain in the acceleration signals between upper arm and forearm, and between hand and finger. The phase lag of the arm units within each of these respective segment pairs was close to in phase or 0 deg. Significant coherence in the frequency domain was also evident between upper arm and hand motion, with the phase lag between these segments being close to 180 deg out of phase. The Ap En analysis of the acceleration signals revealed that there was more regularity to the upper arm and hand accelerometer signals than the forearm and finger signals. The findings show that the intra-limb coordination of the arm links in a two-limb postural pointing task is effected by a compensatory synergy organized about the action of the wrist and shoulder joints. This compensatory synergy reduces the coordination of the 4 within-limb degrees of freedom (arm links) to, in effect, a single degree of freedom arm control task that is not coupled in organization to the motion of the other limb or the torso. It is proposed that this coordination solution reduces the degrees of freedom independently regulated for realization of the task goal but preserves independent body segment control in critical degrees of freedom for potential adaptation to postural perturbations.
DOI：
10.1093/gerona/50a.5.m263
发表时间：
1995-09-01
影响因子：
5.1
作者：
JUDGE, JO;KING, MB;WOLFSON, LI
通讯作者：
WOLFSON, LI
毒理学中运动功能的量化。
影响因子：
3.5
作者：
Newland,MC
通讯作者：
Newland,MC