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So What Went Wrong?
Published in Sidney Dekker, The Field Guide to Understanding Human Error, 2017
As indicated in the example above, fatigue can be the result of a number of factors (or a combination), for example:Workload intensity (or, conversely, inactivity) and sustained effort (performance deteriorates as a function of “time on task”);Physical and psychological exertion;Sleep deprivation or other sleep disturbances;Time of day effects;Cyrcadian desynchronization (e.g. jet lag).
Assessing and Managing Shift Work-Related Fatigue: A Practical Approach
Published in Philip D. Bust, Contemporary Ergonomics 2007, 2018
While these symptoms can be an unpleasant experience for the individual shift worker and may have a long-term detrimental effect on their health and well-being, it is fatigue that has the potential for the most immediate consequences. Fatigue is a complex subject. Shaw & Mackay (2002) discussed the various types of fatigue before focusing on general fatigue associated with hours of work and mental fatigue and argued that it is difficult to distinguish the two. General fatigue can be described as a decline in mental and/or physical performance and occurs after prolonged exertion, lack of sleep or disruption of the internal clock. But its onset is also related to workload and level of stimulation.
Comparison of the observer, single-frame video and computer vision hand activity levels
Published in Ergonomics, 2023
Robert G. Radwin, Yu Hen Hu, Oguz Akkas, Stephen Bao, Carisa Harris-Adamson, Jia-Hua Lin, Alysha R. Meyers, David Rempel
The videos were previously coded for exertion and rest time by multiple analysts from the individual institutions of the ULMSDC. Since the videos were previously coded using MVTA for a different purpose, the single-frame analysis was conducted for the current study using the following definition of exertions. An exertion was defined as a visible hand or forearm muscular effort while grasping an object or applying a force (e.g. hold, manipulate, trigger, push, pull, or handle an object) during task performance, regardless of the force required. Exertions that were less than 10% MVC were excluded and contributed to rest time. Every qualifying exertion was included, even if it was not followed by a pause (e.g. when a sequence of exertions occurred while retaining an object, or when grasp of an object was released and immediately followed by another grasp).
Effects of three low-volume, high-intensity exercise conditions on affective valence
Published in Journal of Sports Sciences, 2020
Matthew Haines, David Broom, Warren Gillibrand, John Stephenson
An important yet rarely considered issue when measuring theoretical constructs such as RPE, is that they are understood using arbitrary scales for which considerable interpretation and subjective thought process influence results. Perceived exertion or effort is a cognitive feeling of work associated with voluntary actions during exercise, and is influenced by anticipatory regulation comprising efferent output such as awareness of central motor commands to recruit muscle motor units (Pageaux, 2016; Tucker, 2009). However, it is a common and inaccurate assumption that afferent feedback from homoeostatic disturbance also contributes significantly to the perception of effort (Marcora, 2009). Perceptions of “effort” and “discomfort” might be conflated if instructions given to participants do not clearly emphasise narrow definitions (i.e., perception of effort during exercise is independent of afferent feedback from skeletal muscles), reducing validity when implementing RPE scales. In the current study, participants were encouraged to pedal at maximal intensity for all three exercise conditions, which theoretically should have elicited maximal perceptions of effort. However, observed values were lower than maximal and varied between conditions suggesting that the measure of RPE might not be reflective of the intended construct. A possible explanation for this is that participants anchored their RPE values with discomfort or did not fully understand what they were rating. Furthermore, it is not clear how affect is influenced by perceived effort or discomfort, although the FS aims to measure core affect which is a neurophysiological state consciously accessible as a simple primitive non-reflective feeling (Russell & Feldman Barrett, 2009). Participants are able to differentiate between effort and discomfort during resistance training using novel scales (Steele, Fisher, McKinnon, & McKinnon, 2017b), but current research has not attempted to verify this finding in response to high-intensity repeated sprints. Examination of this issue would improve understanding of the role these perceptions have in regulating exercise intensity providing practical information on exercise tolerance (Abbiss, Peiffer, Meeusen, & Skorski, 2015; Steele et al., 2017b).