Background

Reaction time task performance using electromyography (EMG) has been widely studied in the evaluation of motor responses. However, specific testing conditions with tray usage and the reliability of the bilateral trunk muscle reactions have not been proven.

Research Questions

Are there internal consistencies of the reaction times for a particular condition, such as a handheld task, among the examiners? Is there a delayed reaction time on the dominant abdominal muscle in response to a treadmill-induced slip perturbation while holding or not holding a tray?

Methods

One hundred and nineteen right upper and lower limb dominant individuals (71 female and 48 male subjects) were exposed to a treadmill-induced slip perturbation (0.24 m/s velocity for 1.2 cm) for 0.10 s in standing. The EMG electrodes were placed on both sides of the rectus abdominis (RA) and erector spinae (ES) muscles. The reliability of the test was established by using Cronbach’s alpha, intra-class correlation coefficients (ICC_{2, k}), and the standard error of measurements.

Results

The results for holding a tray indicated a high degree of consistency based on Cronbach’s alpha for the left RA (0.79), right RA (0.86), left ES (0.82), and right ES (0.73) muscles. However, there was a significant reaction time difference among trunk muscles (F = 10.58, p = 0.002) while not holding a tray. The post-hoc results indicated that the right RA muscle was delayed more than the bilateral ES muscles, although there was no significant difference with the left RA muscle.

Significance

Overall, the EMG analyses for the reaction times were highly consistent with and without tray usage. The reaction times of the dominant abdominal muscles were delayed while not holding a tray. Given the high reliability, compensatory strategies by trunk dominance might be considered with a tray usage task.

中文翻译：

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跑步机引起滑倒扰动后，拿着和不拿着托盘时，延迟的躯干肌肉反应时间的内部一致性。

背景

使用肌电图（EMG）的反应时间任务表现已在运动反应评估中得到了广泛研究。但是，尚未证实使用托盘使用的特定测试条件以及双侧躯干肌肉反应的可靠性。

研究问题

检查者之间是否存在针对特定条件（例如手持任务）的反应时间的内部一致性？握着或不握着托盘时，跑步机引起的滑移扰动会导致优势腹部肌肉的反应时间延迟吗？

方法

119名右上肢和下肢优势个体（71名女性和48名男性受试者）在跑步机上引起的滑倒扰动（0.2 cm的速度为0.24 m / s，持续1.2 cm）站立0.10 s。EMG电极放置在腹直肌（RA）和竖脊肌（ES）肌肉的两侧。通过使用Cronbach's alpha，组内相关系数（ICC _2，k）和测量的标准误差来确定测试的可靠性。

结果

保持托盘的结果表明，基于左臂（0.79），右臂（0.86），左ES（0.82）和右ES（0.73）肌肉的Cronbach's alpha高度一致性。但是，在不握托托板的情况下，躯干肌之间的反应时间存在明显差异（F = 10.58，p = 0.002）。事后结果表明，右RA肌肉比双侧ES肌肉延迟更多，尽管与左RA肌肉没有显着差异。

意义

总体而言，无论是否使用托盘，EMG的反应时间分析都高度一致。腹主动脉的反应时间被延迟，而没有保持托盘。鉴于可靠性高，可以在托盘使用任务中考虑通过干线优势进行补偿的策略。