https://cn.nytimes.com/health/20161220/why-fidgeting-is-good-medicine/dual/ https://baike.baidu.com/item/%E6%8A%96%E8%84%9A/9675418 https://www.zhihu.com/question/25395748/answer/30837598
抖脚有益身体下部血液循环,有益健康。 抖脚能使人专注,提高效率。