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Industrial Engineering

Tuesday, 7 August 2012

ERGONOMICS AND THE SEDENTARIAN

Journal: Ergonomics and the Sedentarian, QAS 515 – Human Factors,

November 29, 2005

Author: Joel Prechtl

ABSTRACT

          The objective of this paper is to explore the ergonomic impact of the environment and mental stimuli on the sedentary worker. Based on Bureau of Labor Standards statistics, jobs that are less active, such as those of secretaries, various professional managers, and accountants are expected to show an increase from a low of 3.0 % to a high of over 40% by the year 2012. It appears fairly certain that the trend toward sedentary-type jobs is rising.

INTRODUCTION

         

          Repetitive strain injuries (RSIs) – which are sometimes included in the category of Upper Limb Disorders (ULDs) since RSI does not cover all “upper limb” disorders - are the nation’s most common and costly occupational health problem, affecting hundreds of thousands of American workers, and costing more than $20 billion a year in worker’s compensation. In 1992, there were 281,800 reports of repetitive task injuries, more than double that reported just 4 years earlier. Of 32,838 musculoskeletal disorders (MSDs) reported in 2001 in Texas, 3,146 were due to back pain, carpel tunnel syndrome, tendonitis, or tenosynovitis. Of the 522,528 persons reporting MSDs that year, 212,959, or 40.8%, came from the more sedentary managerial and professional, technical, sales, administrative, and service positions than from more active labor, “blue collar” positions.

With the advent of the computer and a multitude of “labor-saving” machines for both the office and the factory (such as the personal desk computer), jobs that were typically manually intensive have been quickly regenerated into less manual labor intensive ones, and the operator who was previously threatened by physical exertion, injury and exhaustion is now even more threatened by physiological illnesses caused by inactivity. Carpal tunnel syndrome, first described 125 years ago, has become a very common affliction for typists, data entry clerks, and persons whose work entails a lot of hand and wrist movement. It is the most reported medical problem, and now afflicts over 8-million Americans.

PHYSICAL MALADIES

        Musculoskeletal disorders (MSDs), or injuries that affect the musculoskeletal system, abound with the sedentarian. Tendinitis, tenosynovitus, epicondylitis, carpal tunnel syndrome, bursitis, deQuervain’s disease, ganglion cyst, and thoracic outlet syndrome are a few of those with specific names, but in addition, there are numerous lesser-defined sprains, strains, tears, or even just pain. With rapidly changing jobs and the equipment used for them, some of the afflictions are actually starting to be named after them. In the worst cases, unlimited medical treatment becomes necessary. Carpal tunnel syndrome, for instance, is a chronic condition in which nerve compression in the wrist leads to abnormal sensations, pain, or loss of function in parts of the hand, and is generally diagnosed with one or more of the following experiences:

•       A painful or tingling feeling in one or both hands

•       A feeling that the fingers are swollen

•       A feeling of “uselessness” in the hand or that the hand is “asleep”

•       Inability to make a fist

•       Frequently dropping things

•       Decreased ability to perform everyday tasks, like telephoning, cooking, grooming, etc.,

•       A decreased power in the wrist

•       A possible inability to discern hot from cold by touching

•       Pain with wrist or finger movement.

EXHAUSTION WITHOUT EXERTION

        As paradoxical as it sounds, much of the exhaustion suffered by the less active workforce stems from their inactivity. Fibromylagia and chronic stress disorder (CSD) are both illnesses that are characterized by physical exhaustion, lack of energy or motivation to do work, feeling extremely tired or sleepy, and heightened anxiety. Again, based on figures taken from the U.S. Dept. of Labor Bureau of Labor Statistics, these are also illnesses more common to the worker in the office than those in the factory or service industries, where the work entails more movement and physical exertion.

Boredom with one’s work can even result in a feeling of exhaustion. Boredom is the worker’s emotional response to repetitive, monotonous tasks, and often results in ineffectiveness due to - and aggravated by - a feeling of tiredness or fatigue. This is an obvious example of what is referred to as “mental fatigue.” Where physical fatigue is defined as the disinclination to continue a task due to physical factors, the term mental fatigue is used by some psychologists to describe a condition where there is a disinclination to continue a task due to psychological factor.

STRESS

Evidence shows stress is related to physical illness, and there are various psychological approaches toward determining if stress exists, and if so, how much. The Social Readjustment Rating Questionnaire (Holmes and Rahe), the Life Event Scale (Tennant and Andrews), and the Recent Life Events Interview (Paykel) can all help to quantify and identify stress and ought to be used in all industries. The most horrible aspect of stress is its invisibility to others. Thus, investigative techniques ought to be used to uncover its presence, and prevent its degenerating into a debilitating condition.

The biggest threat to the sedentary worker could very well be himself. Anxiety, a dis-stress that results from the challenges confronting the individual, has been shown to have a direct affect on health. It can compromise the body’s immune system, speed the development of cancer, increase one’s vulnerability to viral infections, accelerate the onset of Type I diabetes and the course of Type II diabetes, and ulcerate the gastrointestinal tract. Even the brain can be physically affected by stress-caused damage to the hippocampus, and thus, have a diminishing affect on one’s memory.

WORKLOAD

           The workload put upon any worker can be too easy, just right, or too difficult. Either of the extremes – too easy or too difficult – can cause the worker stress. Both sedentary as well as physically active workers, of course, can experience these stressful influences, but the “desk job” typically does not have the product, or tangible output that measures a production worker’s success. Reports and communications witnessed by just a few

people – which is typical of the “desk job” – provide little justification to the majority for being kept busy. Thus, the person doing the job is often the object of the question, “just what does that person do?” This, in itself, is a seriously de-motivating and stress inducing situation to be in. Good communication between the manager and his subordinates can help to foster an environment in which everyone is aware and respectful of other’s functions.

PSYCHOSOCIAL FACTORS

            Psychosocial risk factors stem from the worker’s psychological response to the work and the workplace. They are directly related to the working relationships that one has with peers, superiors and subordinates, the amount of work they are expected to do, the deadlines they are expected to meet, and whether or not they have true control over their own work. Some of the more common causal factors for psychosocial threat are:

•       little control over one’s work and work methods;

•       inability to make full use of one’s skills;

•       no involvement in decisions affecting them;

•       repetitive, monotonous tasks;

•       being paced by a machine (i.e., monitoring a machine);

•       extreme work demands;

•       administrative systems that encourage working too quickly or without breaks;

•       limited socialization opportunity;

            Psychosocial issues are best addressed with full consultation and involvement of the workforce. The psychosocial “environment” can be improved by:

•       combining or otherwise revising tasks to eliminate monotonous jobs;

•       ensuring that the workload is do-able, neither too much nor too little;

•       ensuring that deadlines are reasonable and achievable;

•       encouraging teamwork;

•       ensuring good communication;

•       monitoring productivity to ward against excessive overtime or exertion;

•       eliminating, wherever possible, piece-rate, or “reward for quantity” pay systems;

•       providing appropriate training.

ENVIRONMENTAL CONSIDERATIONS

. The principal factors affecting one’s ability to see things clearly are:

•       glare

•       the luminance (brightness) difference between what is being looked at and its environment

•       the amount of light (illumination)

•       the viewing distance

•       the clarity (readability) of the object being viewed

•       the employee’s visual acuity

Noise can:

•       create negative emotions (anger, fear, anxiety)

•       delay or disturb one’s sleep

•       override more pleasant sounds

•       change body chemistry, both temporarily and permanently

•       affect temporarily or permanently one’s ability to hear

•       interfere with some sensory and perceptual capabilities

TRAINING AND EDUCATION

             There is a host of information available on the internet regarding preventive measures that can be taken to avoid MSDs as well as psychosocial stress factors, discussed earlier. Ergonomics.com, is a web site devoted to the exchange of information between the fields of ergonomics and the Alexander Technique, developed in the early 20^th century, before ergonomics even became a recognized science. The technique essentially educates people as to ways in which they are misusing their bodies, and how everyday work habits may be harming them. It is sort of the Scientology of Ergonomics, but nonetheless, has its followers.

CONCLUSION

           Yet there remains a hole in the system with the involvement of human factor analyses, period. This class is an integral, required component of a master’s degree curriculum, but in my college courses for industrial engineering and management, I was never before required to study or at least comprehensively understand ergonomics for what it really is. Going into this class I remembered workplace layouts that I had done in my previous jobs, and thought myself to be pretty complete in my analyses. Judging from what I’ve learned in this course, I was wrong, and my projects very likely sub-optimal. I now believe that ergonomics should be a required course in every single major where the student is going to be ultimately working anywhere, doing anything whatsoever …

 Posted by JEETU RANA