The Effects of Anchor Scheme on the Central and Peripheral Contributions to Performance Fatigability, Perceived Responses and Sensations, and Psychological Factors Following Sustained, Isometric Forearm Flexion Tasks to Failure

Authors

Robert Walker Smith, University of Nebraska-LincolnFollow

First Advisor

Terry J. Housh

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Nutrition and Human Sciences (Exercise Physiology)

Date of this Version

8-2024

Document Type

Dissertation

Citation

A dissertation presented to the faculty of the Graduate College of the University of Nebraska in partial fulfillment of requirements for the degree of Doctor of Philosophy

Major: Nutrition and Human Sciences (Exercise Physiology)

Under the supervision of Professor Terry J. Housh

Lincoln, Nebraska, August 2024

Comments

Copyright 2024, Robert Walker Smith. Used by permission

Abstract

The Effects of Anchor Scheme on the Central and Peripheral Contributions to Performance Fatigability, Perceived Responses and Sensations, and Psychological Factors Following Sustained, Isometric Forearm Flexion Tasks to Failure Robert W. Smith, Ph.D. University of Nebraska, 2024 Advisor: Terry J. Housh This study assessed time to task failure (TTF), performance fatigability (PF), neuromuscular responses, central and peripheral measures of fatigue, and perceived responses including sensations and psychological factors that contributed to task termination during sustained, isometric forearm flexion tasks anchored to ratings of perceived exertion (RPE) and the torque corresponding to RPE. Fifteen men (age = 21.5 ± 2.3 yrs; height = 183.6 ± 6.7 cm; body mass = 87.2 ± 12.5 kg) completed maximal voluntary isometric contractions (MVICs) before and after sustained tasks anchored to RPE = 3, 6, and 9 (RPEFTs) and the torque produced at the RPE values (TRQFTs). Amplitude (AMP) and mean power frequency (MPF) contents from the electromyographic (EMG) and mechanomyographic (MMG) signals were recorded. Measures of central and peripheral fatigue were assessed using the interpolated twitch technique (ITT). Perceived measures including RPE, affective valence, and ratings of fatigue (ROF) were recorded. After the tasks, subjects were given a fatigue task questionnaire (FTQ) to evaluate task disengagement caused by perceived sensations and psychological factors. Regression was used to examine individual and composite torque and neuromuscular responses versus time. Repeated measures ANOVAs were conducted to assess the mean differences for the dependent variables and correlation analyses were used to examine the association between the FTQ items and TTF and PF. The TTF was greater during the RPEFTs than the TRQFTs, but PF was similar following the tasks. The neuromuscular responses, composite patterns of responses, and measures reflective of central and peripheral were influenced by anchor scheme and/or intensity. Perceived fatigue, pain, loss of focus, boredom, and maximal effort contributed to task termination. The FTQ items were not related to typical measures of fatigability. Because performance fatigability, RPE, affective valence, and ROF were similar across the tasks, it was hypothesized that homeostatic perturbations reached a sensory tolerance limit causing similar magnitudes of performance fatigability and perceived fatigability.

Advisor: Terry J. Housh

Recommended Citation

Smith, Robert Walker, "The Effects of Anchor Scheme on the Central and Peripheral Contributions to Performance Fatigability, Perceived Responses and Sensations, and Psychological Factors Following Sustained, Isometric Forearm Flexion Tasks to Failure" (2024). Dissertations and Doctoral Documents from University of Nebraska-Lincoln, 2023–. 165.
https://digitalcommons.unl.edu/dissunl/165