Smith Robert W, Housh Terry J, Arnett Jocelyn E, Anders John Paul V, Neltner Tyler J, Ortega Dolores G, Schmidt Richard J, Johnson Glen O
Exercise Physiology Laboratory, Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE 68510, USA.
The Exercise Science Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43017, USA.
J Funct Morphol Kinesiol. 2023 Apr 25;8(2):49. doi: 10.3390/jfmk8020049.
The present study examined the effect of anchor schemes on the time to task failure (TTF), performance fatigability, neuromuscular responses, and the perceived sensations that contributed to task termination following the sustained, isometric forearm flexion tasks. Eight women completed sustained, isometric forearm flexion tasks anchored to RPE = 8 (RPEFT) and the torque (TRQFT) that corresponded to RPE = 8. The subjects performed pre-test and post-test maximal isometric contractions to quantify performance fatigability and changes in electromyographic amplitude (EMG AMP) and neuromuscular efficiency (NME). In addition, the subjects completed a post-test questionnaire (PTQ) to quantify the contributions of perceived sensations to task termination. Repeated measure ANOVAs were used to assess the mean differences for TTF, performance fatigability, and neuromuscular responses. Wilcoxon Signed Rank Tests were used to assess the differences between anchor schemes for the average values from the PTQ item scores. For TTF, the RPEFT was longer than the TRQFT (174.9 ± 85.6 vs. 65.6 ± 68.0 s; = 0.006). Collapsed across the anchor scheme, there were decreases in torque (23.7 ± 5.5 Nm vs. 19.6 ± 4.9 Nm; < 0.001) and NME (1.00 ± 0.00 vs. 0.76 ± 0.15; = 0.003). There were no significant ( 0.577) changes for EMG AMP. For the PTQ, there were no differences ( 0.05) between anchor schemes. There were, however, inter-individual differences in the response scores. The current findings indicated that performance fatigability was likely due to peripheral fatigue (based on NME), not central fatigue (based on EMG AMP). Furthermore, the use of a PTQ may serve as a simple tool to assess the contributions of perceived sensations to task termination.
本研究考察了锚定方案对任务失败时间（TTF）、运动疲劳性、神经肌肉反应以及在持续等长前臂屈曲任务后导致任务终止的感知觉的影响。八名女性完成了锚定到主观用力程度（RPE）=8的持续等长前臂屈曲任务（RPEFT）以及与RPE = 8相对应的扭矩任务（TRQFT）。受试者进行了测试前和测试后的最大等长收缩，以量化运动疲劳性以及肌电图幅度（EMG AMP）和神经肌肉效率（NME）的变化。此外，受试者完成了一份测试后问卷（PTQ），以量化感知觉对任务终止的影响。重复测量方差分析用于评估TTF、运动疲劳性和神经肌肉反应的平均差异。Wilcoxon符号秩检验用于评估PTQ项目得分平均值在锚定方案之间的差异。对于TTF，RPEFT比TRQFT更长（174.9±85.6对65.6±68.0秒；P = 0.006）。综合锚定方案来看，扭矩（23.7±5.5牛米对19.6±4.9牛米；P<0.001）和NME（1.00±0.00对0.76±0.15；P = 0.003）有所下降。EMG AMP没有显著变化（P = 0.577）。对于PTQ，锚定方案之间没有差异（P>0.05）。然而，反应得分存在个体差异。当前研究结果表明，运动疲劳性可能是由于外周疲劳（基于NME），而非中枢疲劳（基于EMG AMP）。此外，使用PTQ可能是一种评估感知觉对任务终止影响的简单工具。
