Q.3. Explain the term fatigued.
Related Question -
Q. Elaborate some measures to reduce the fatigue. (AKTU. 2009 - 10)
Ans. According to Dill (1933): -
We can say that fatigue is not an entity but merely a convenient word to describe a variety of phenomena. The common fallacy of supposing that word fatigue corresponds to a definite thing has been a source of much confusion. Fatigue from short bursts of activity, whether by the whole body or by isolated muscular groups, is characterized by increase in lactic acid and temporary inability to continue. Fatigue from depletion of fuel reserves does not occur commonly in man, but when it does, chemical analysis of the blood reveals a low level of blood sugar. Fatigue from working in a hot environment has several manifestations, the most simple to measure being the increase in heart rate. Finally in the instance of two individuals doing the same task, one may become more fatigued than the other because the poor nervous coordination of the unskillful man makes it necessary for him to expend more energy than the other. In general, fatigue from any of these causes is greater the more nearly the individual approaches his capacity for work.
The term “fatigue” is defined as an altered psychological and physiological state in relation to the status of recovery or normal capacity. Music defines fatigue as “ a condition caused by activity in which output produced by that activity tends to be relatively poor and the degree of fatigue tends to vary directly with the poorness of output,” Music, however, is himself dissatisfied with this definition because fatigue cannot be directly measured and because diminished output may also be a result of distraction. He concludes that the term “fatigue” should be banished from scientific terminology. But banning the word would still leave the phenomenon that by any other name would still be fatigue. It would be pointless to argue with a fatigued worker that there is no such thing as fatigue be cause fatigue does not stand the rigors of scientific tests and standards.
Whatever fatigue is, it is safe to say than any muscular work, even that involved in sitting in a chair, will result in fatigue provided the work of the muscles and the resulting expenditure of energy are at a faster rate than is recovery. The major difficulty in understanding the true nature of fatigue is caused by the fact that many factors in addition to muscle use contribute to its onset. The length of the work period, the speed of work, the extent of the musculature involved, and the tensions accompanying the task are a few of these factors. Further complications are caused by the fact that industrial fatigue rarely concerns a single muscle but rather the individual as a whole. Depending on the strength, stamina, and preparation of the individual, fatigue is manifested at different rates in different people.
In some respects no one can ever hope to eliminate fatigue from work unless the work can proceed at the exact rate at which recovery takes place and all the other factors contributing to fatigue can be eliminated. And yet some people set their pace on he job so that recovery seems to take place faster than the onset of fatigue. Half seriously, this might explain the stenographer who comes to work in the morning very fatigued but somehow manages to gain energy during the day so that she is able to keep her date in the evening, only to be fatigued the next morning.
Psychologists can help to eliminate much of the unnecessary fatigue that is caused by unfavorable conditions on the job. Inefficient work spaces, inefficient work methods, inefficient tools, and inefficient people to do the work cause much unnecessary fatigue. These causes can be attacked and conditions changed so as to eliminate or reduce much fatigue on the job.
A simple approach to an understanding of fatigue has been the study of it in the laboratory. An early study of this nature was conducted by Mosso when he constructed an ergograph to record and measure the work done by the muscles in flexing a finger. By attaching a weight to a string tied to a finger and strapping the hand so that only this finger was allowed to move, it was possible to obtain a sample work or fatigue curve. Using this technique, Mosso demonstrated the rate and extent of the work that could be done by a single finger lifting a specific weight. He was also able to demonstrate that if a fatigued muscle is forced to work, the period of recovery is prolonged. Thus if a few minutes is required for recovery after a 10 - minute work period but the work period is nevertheless increased to 15 minutes, recovery requires more than one and a half times the time required after the 10 - minute work period. Although Mosso’s ergograph does study fatigue, it has the obvious disadvantage of doing so under extremely unnatural conditions; furthermore, no job in industry is likely to require the movement of only one finger.
Vernon (1924) developed a variation of the dynamometer which enables one to study the effects of work when the larger muscles of the body are involved. His apparatus required the subject to pull with both hands on a handle attached to a spring balance; the pull on the balance was recorded by a pointer on a revolving drum. With this apparatus Vernon was able to show that the strength of the pull varies with the height of the handle. He also demonstrated that the introduction of rest pauses increases the capacity for work, and further, that a change of posture during the rest pauses helps recovery to a greater extent than merely stopping work. Vernon’s study has a more direct bearing on various industrial jobs and is a strong argument in favor of introducing rest pauses during the work period. It also recognizes the benefits to be derived from encouraging employees to change their posture from that normal during the work period. Many other studies of a similar nature have been made in the laboratory, but each has the disadvantage that the subject is not actually working on a job. Inferences drawn from the laboratory studies may not apply to industry because differences in work speed, pace and continuity may exist.
