This study investigated effects of mirror and metronome use on spontaneous upper body movements by 10 preprofessional dancers in a motor task in which maximally diverse upper body movement patterns were targeted. Hand and trunk accelerations were digitally recorded utilizing accelerometers and analyzed using polar frequency distributions of the realized acceleration directions and sample entropy of the acceleration time. Acceleration directions were more variably used by the arms than by the torso, particularly so when participants monitored their performance via a mirror. Metronome use hardly affected the predictability of the acceleration time series. The findings underscore the intrinsic limitations that people experience when being asked to move randomly and reveal moderate effects of visual and acoustic constraints on doing so in dance.

这项研究调查了镜子和节拍器的使用对10位专业舞者在一项运动任务中针对上身运动的自发性上身运动的影响，这项运动针对的是上身运动的最大形式。使用加速度计以数字方式记录手和躯干的加速度，并使用已实现的加速度方向的极点频率分布和加速度时间的样本熵进行分析。手臂而不是躯干使用的加速度方向变化更大，尤其是当参与者通过镜子监控其表现时。节拍器的使用几乎不会影响加速时间序列的可预测性。这些发现强调了人们被要求随机移动时会遇到的固有局限性，并揭示了视觉和听觉约束对舞蹈的适度影响。