The stability of rhythmic interlimb coordination is governed by the coupling between limb movements. While it is amply documented how coordinative performance depends on movement frequency, theoretical considerations and recent empirical findings suggest that interlimb coupling (and hence coordinative stability) is actually mediated more by movement amplitude. Here, we present the results of a reanalysis of the data of Post, Peper, and Beek (2000), which were collected in an experiment aimed at teasing apart the effects of frequency and amplitude on coordinative stability of both steady-state and perturbed in-phase and antiphase interlimb coordination. The dataset in question was selected because we found indications that the according results were prone to artifacts, which may have obscured the potential effects of amplitude on the post-perturbation stability of interlimb coordination. We therefore redid the same analysis based on movement signals that were normalized each half-cycle for variations in oscillation center and movement frequency. With this refined analysis we found that (1) stability of both steady-state and perturbed coordination indeed seemed to depend more on amplitude than on movement frequency per se, and that (2) whereas steady-state antiphase coordination became less stable with increasing frequency for prescribed amplitudes, in-phase coordination became more stable at higher frequencies. Such effects may have been obscured in previous studies due to (1) unnoticed changes in performed amplitudes, and/or (2) artifacts related to inappropriate data normalization. The results of the present reanalysis therefore give cause for reconsidering the relation between the frequency, amplitude, and stability of interlimb coordination.

中文翻译：

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基于严格归一化程序的幅度对插值协调稳定性影响的重新评估

节律性跨肢协调的稳定性取决于肢体运动之间的耦合。尽管充分记录了协调性能如何取决于运动频率，但理论上的考虑和最近的经验发现表明，肢体耦合（以及因此的协调稳定性）实际上更多地是由运动幅度来调节的。在这里，我们介绍了对Post，Peper和Beek（2000）数据的重新分析结果，这些数据是在旨在消除频率和幅度对稳态和摄动信号协调稳定性的影响的实验中收集的相和反相插值协调。选择该数据集是因为我们发现有迹象表明相应的结果容易出现伪像，这可能已经掩盖了幅度对中间插值协调的摄动后稳定性的潜在影响。因此，我们基于运动信号重新进行了相同的分析，该运动信号在每个半周期进行了归一化处理，以获取振动中心和运动频率的变化。通过这种精细的分析，我们发现（1）稳态和扰动协调的稳定性似乎实际上更多地取决于幅度而不是运动频率本身，并且（2）稳态反相的协调性随着频率的增加而变得不太稳定对于规定的幅度，同相协调在更高的频率下变得更加稳定。由于（1）执行幅度的未注意到变化和/或（2）与不适当的数据归一化相关的伪像，在以前的研究中可能无法掩盖这种影响。