Zheng Huifen, Song Qipeng, Zhang Cui, Sun Wei, Mao Min, Zhang Xinyan, Zhu Xiuqi, Ma Gang, Mao Dewei
Shandong Sport University, Jinan, China.
Shandong Institute of Sport Science, Jinan, China.
J Biomech. 2020 Dec 2;113:110088. doi: 10.1016/j.jbiomech.2020.110088. Epub 2020 Oct 24.
Stair descent imposes a significant challenge for dynamic stability among young adults. The effect of a concurrent text-based math task on dynamic stability control remains unclear during stair descent when considering the influence of gait velocity. Twenty-six participants performed three successful stair descent trials under TEXTING or NO-TEXTING conditions at their preferred speed. Synchronous kinematics and kinetics were collected by an eight-camera Vicon infrared motion capture system and two force platforms. Repeated measures analysis of covariance and Wilcoxon signed rank test were used to analyze the differences between the two different task conditions with gait velocity as a covariate. The outcomes indicated that under TEXTING condition, sagittal margin of stability increased at right-foot-landing; step cadence, double-support percentage, sagittal and frontal joint moment decreased; and sagittal and frontal joint angles were also modified. It is concluded that concurrent TEXTING impaired sagittal and frontal stability control during stair descent despite slowing down the step cadence. Knee and ankle joint adjustment strategies were mainly adopted in response to stability control in the sagittal plane with the interference of TEXTING, whereas the hip joint adjustment strategy was adopted in the frontal plane. In conclusion, texting behaviors on mobile phones should be minimized during stair descent.
下楼梯对年轻人的动态稳定性构成了重大挑战。在考虑步速影响的情况下，下楼梯时基于文本的数学任务对动态稳定性控制的影响仍不清楚。26名参与者在“发短信”或“不发短信”条件下，以他们偏好的速度成功完成了三次下楼梯试验。通过一个八摄像头的Vicon红外运动捕捉系统和两个测力平台收集同步运动学和动力学数据。采用重复测量协方差分析和Wilcoxon符号秩检验，以步速作为协变量，分析两种不同任务条件之间的差异。结果表明，在“发短信”条件下，右脚着地时矢状面稳定裕度增加；步频、双支撑百分比、矢状面和额状面关节力矩减小；矢状面和额状面关节角度也发生了改变。研究得出结论，尽管步频减慢，但同时发短信会损害下楼梯时矢状面和额状面的稳定性控制。在短信干扰下，矢状面稳定性控制主要采用膝关节和踝关节调整策略，而额状面则采用髋关节调整策略。总之，下楼梯时应尽量减少使用手机发短信的行为。
