Computer Ergonomics in the Workplace
Business strive for high production at low cost. This would result in the highest profit
for a company. To many businesses, this is only a mirage. This is because the 'low
cost' of the business usually results in a 'high cost' for the employees. This high cost
is lower quality workplace items, lower salaries, less benefits, etc. These costs
create an upset workplace environment. Companies understand that the more efficient
their workers are, the more productive their business will become. Although this will
take lots of money at first, the result will be extreme success.
There exist many different things in the workplace that add to stress and injuries. They
range from lifting heavy boxes to typing too much on the keyboard. This paper will be
focusing on the principals of ergonomics in the computer workstation. According to the
Board of Certification for Professional Ergonomists (BCPE), the definition of ergonomics
"is a body of knowledge about human abilities, human limitations and human
characteristics that are relevant to design. Ergonomic design is the application of this
body of knowledge to the design of tools, machines, systems, tasks, jobs, and
environments for safe, comfortable and effective human use."(BCPE, 1993) In the average
computer workstation, employees are prone to over a dozen hazards. There exist two
factors that can prevent this: forming good work habits and ergonomically designed
computer workstations. We will discuss these
preventions throughout the paper.
First, a few terms may need defining. Repetitive Strain Injuries (RSI) takes place from
the repeated physical movements of certain body parts which results in damage to tendons,
nerves, muscles, and other soft body tissues. If these injuries are not taken care of
immediately, permanent damage could be done. A few common results of RSI's that were not
taken care of right away are injuries like Carpal Tunnel Syndrome, Tendentious,
Tenosynovitis, DeQuervain's Syndrome, Thoracic Outlet Syndrome etc. All of these are
able to be prevented by the use of good working habits and ergonomic engineering.i
Usually, ergonomically designing a computer workstation would cost about $1000. This
expense could be eliminated by the formation of good work habits. This is essential for
the safety of computer terminal employees. There exist a number of precautions that can
be taken into consideration when dealing with a computer workstation. We shall discuss
six of them.
First, the whole body must be relaxed. The correct posture is shown in Figure 1. Notice
that the arms and thighs are parallel to the floor and the feet are flat on the floor.
Also notice that the wrists are not bent in any way. This is one of the most damaged
parts of the body when speaking of (RSI).
Figure 1
The wrists, when typing, should not be rested on anything when typing. This would cause
someone to stretch their fingers to hit keys. They should also be straight: not bent up,
down, or to the side. The correct position is portrayed in figure 2, incorrect in figure
3. Studies show that these steps are easier to perform while the keyboard is not tilted
toward the user. When it is tilted, it is natural to rest your wrists on the table.
This puts the keyboard at a lower level, creating a more natural position.
Another practice that should be taken into consideration is how hard you press on the
keys. The user is not supposed to hit the keys. This may cause damage to the tendons
and nerves in the fingers. Instead, use a soft touch, not only will your fingers thank
you for it, the keyboard will too!
Keeping in mind not to stretch your fingers when typing, use two hands to perform
double-key operations. For example, you need to capitalize the first letter in every
sentence, therefore, you would hold down the shift and press the first letter.
Figure 2 Figure 3
This is a double key operation. Instead of stretching two fingers on one hand to do this
operation, use both hands.
No matter what kind of a pace you are on when doing work, take breaks every ten minutes
or so in addition to your hourly breaks. These breaks need only be a few moments at a
time. If breaks are not taken at this pace, you may be subjecting yourself to injuries
in the back, neck, wrists and fingers. Also, when using the mouse, do not grip it
tightly. Most mice that are used in offices today are not designed with human factors in
mind. Some mice, like the Microsoft mouse, are designed to fit the contour of your hand.
Although this may seem nice, it does not mean that one will be able to use it for hours
on end and not feel any discomfort in the hand. Other mice, that will be mentioned
later, are designed for comfortable use for extended periods of time.
Try to keep your arms and hands warm. Cold muscles are more apt
to strain and injury than warm ones. Wearing a sweater or a long-sleeved shirt can be of
great importance especially when working in air-conditioned offices.
And finally, do not use the computer more than necessary. Your body can handle only so
much strain on the neck, shoulders, wrists and fingers. Even with the greatest
state-of-the-art ergonomically designed computer workstation, people put themselves at
risk.
Some people tend to use their break times at work playing video games. This is a good
way to ease the mind of everyday pressure (to some extent). This is also a good example
of using the computer 'more than necessary'. If a person needs to use a computer for
video games, take a break every ten minutes or so, as mentioned above.ii
All of these strategies mentioned above are things that can be done to reduce injuries
when using a computer for an extended period of time. They do not include any type of
ergonomically designed hardware. If employees form these habits, there would be less
need to purchase any ergonomic equipment for the office. But, making new habits is not
the easiest thing to do for most people. Next, we will take a look at how a computer
workstation should be set up. The following data was retrieved by an on-line quiz from
the University of Virginia.
The first question about computer workstations poses a question about the seat being too
high. This would cause strain on the legs of the operator causing them to "go to sleep".
Basically, the blood flow to the leg and feet will be cut off.
The next fact presented to us is that the top of the Video Terminal Display (VDT) should
be no higher than eye level. This is one of the most controversial topics because it
deals with the neck and shoulders. Some people state that it should be below, but not at
eye level because our natural tendency is to look down.
Thirdly, the best viewing distance from the VDT is about 24 inches from the screen. This
deals with eye strain. Some people worry about radiation that may be emitted from the
VDT. Radiation is not a big problem with newer monitors. Even old ones have a
protective coating around the screen. This allows very few particles to go through the
screen. Even if they do manage to get that far from the screen, the radiation goes
inches before withering away. The eye strain is the important factor here. Look away at
an object far away from you if eye strain continues to be a problem.
The next question deals with the tilt of the screen. If the monitor should be at or
below eye level, it would be easier to read with a 10 to 20 degree back tilt. Many VDT's
have a tilt on the bottom, if not, a book could propped under the monitor to tilt it back
a bit.
Another question asked is about the height of the keyboard from the floor. It should be
elbow height. As mentioned before, the fore-arms and thighs should be parallel to the
floor. This is possible only if the keyboard is elbow height from the floor.
How should the lighting be in offices when using a computer? It should be a bit dimmer
than normal office lighting. This is so because if the office lighting is brighter,
there will be a lot of glare on the screen. It also has to do with eye strain.
Noise in the work area causes fatigue. This may be true, to add to this statement, it
also causes the computer operator to lose concentration on their work. Not only does
noise affect our concentration and causes fatigue, it obviously can damage one's
hearing.
Using this questionnaire, I conducted a survey among students at Canisius College in
Buffalo, NY. The purpose of the survey was to test the knowledge of the student body as
to their knowledge of VDT's and their safety precautions. In order to accomplish this in
a professional manner, a random sample of students was acquired. In order to obtain a
random sample, certain criteria must be met, too numerous to mention in this essay.
Needless to say, not all of the criteria were met for the sample to be random. The
sample size of the survey was approximately 100 students. The results were not
surprising. There was one problem with the questionnaire : many students did not know
what VDT meant1.
According the survey, 100% of the people was familiar with what
ergonomics is, knew how to reduce tension, what movement in your peripheral vision does,
and what you should do if you should wear bifocal lenses. This question posed a problem
because of the way in which the answer was worded. The correct answer is very specific,
and sticks out over the other possible answers. The rest of the questions were well
worded and not too obvious.
Besides the first and last question, there were a few others that were all answered
correctly. These were questions eleven and twelve. The probable cause for this is that
the questions were easy. The answers were more obvious than the others. If you compare
these questions to the ones that were more difficult (seven and thirteen) the percent
correct differ. Questions seven and thirteen deal with very specific measurements that
are all closely related. These questions are not 'common knowledge' questions. I am
assuming that people were taking educated guesses when encountering these questions.
This could be the reason for the large percent of error in these parts of the survey.
Now that we have discovered the good habits to form when working at computer workstations
and took a look at what a selected college student population knew about VDT's, we will
now take a look at ergonomic engineering and the reason for its emergence.
There are a number of devices ranging from keyboards and mice to chairs and even foot
stands. In this paper we will just review a few of these ergonomically designed items
and why ergonomics is an issue to computer users.
First, we will discuss the purpose of ergonomically designed items. There are a number
of reasons for the emergence of ergonomics. One reason for this is insurance purposes.
Many companies have disability and other types of insurance to cover injuries that occur
while working. This would not be needed as much if there were ergonomically designed
computer workstations. It would save the company insurance hassle and money in the long
run. Another purpose for the emergence of ergonomically designed workstations is that
the injuries due to the overuse of the computers are long lasting. These ailments do not
just go away in time. And one can not put a price on injuries like this. This is why
ergonomics is so important.
Secondly, we will look at an item that effects the common computer
user the most: the keyboard. With computers getting faster and faster every day, it is
about time that people looked at the hazards they pose instead of perfecting them.
Keyboards pose the largest threat to the computer user, not only because it is the most
used input device, but also because of its design. It is a flat, straight input device
that can cause strain and injury to the user if not used properly. Ergonomic engineers
realized this hazard and designed a number of different alternatives. All of the
ergonomically designed keyboards attempt to reduce injuries by studying the natural
position of the fingers, hands and wrists. By using this knowledge, keyboards and mice
are designed. There is no ideal position for the hand as of yet. Hence, there exists
different types of keyboards and mice. Figures 4 - 5 show different styles of keyboards
and mice.
Figure 4 - http://www.earthlink.net/~dbialick/kinesis
Figure 5
Notice the unique structure of the keyboard. It does not even look like one. This may
take time to get used to, but it will payoff in the end.
Not only is there hardware for the reduction of RSI, but there exists software to help
you reduce the RSI. Micronite softwareiii
designed a program called ARMS (Against Repetitive Strain Injury) Which reminds you when
it is time to take a break. Also, it walks you through a series of videos which portray
ways to massage different parts of your hand, neck, and shoulders.
With all of this hardware and software available for business and personal use, who would
not be interested? Well many people think that it will not happen to them until it does.
People should not wait that long. If you use a computer for more than four hours a day,
you are prone to RSI. If your company does not have ergonomically engineered hardware,
software or furniture, then do something about it. It's your health.
1 A copy of the survey is attached to the end of this paper. The correct answer is
bolded.
i URL address : http://webreference.com/rsi.html#whatis
ii URL address : http://www.engr.unl.edu/ee/eeshop/rsi.html
iii URL address : http://www.micronite.com/
Glossary
CGI
"Common Gateway Interface". A standard protocol which allows HTML based forms to send
field contents to a program on the Internet for processing. It also allows the receiving
program to respond by sending an HTML response document.
Email
"Electronic Mail". An electronic document similar to a piece of mail in that it is sent
from one person to another using addresses, and contains information. Email commonly
contains information such as: sender name and computer address, list of recipient names
and computer addresses, message subject, date and time composed, and message content.
Sometimes, an Email message can have attached computer files such as pictures, programs,
and data files.
Firewall
A program or device which serves as an intelligent and secure router of network data
packets. These mechanisms are configured to restrict the flow of packets in different
directions (i.e. to and from the Internet) based on the system addresses (a.k.a. IP
addresses) of the connected computers.
FTP
"File Transfer Protocol". A program or feature popularly used over the Internet to
transfer files between computers.
Hacker
A person who deliberately breaks into computer systems for entertainment, gain, or spite.
The most sophisticated hackers spend all of their time breaking into computers. The risk
that these people pose is that they often steal or damage software systems and
information.
Home Page
A Web Page which is at the root of all Web Pages for a particular Web Site. A Home Page
should portray the image that the company wants to project. Usually, these pages resemble
marketing slicks, but with an interactive slant. This front page of a Web Site then
provides hypertext links to the rest of the Web Site's content and possibly to Home Pages
for other related Web Sites.
HTML
"HyperText Markup Language". A standardized programming language used to create hypertext
documents. Used to create all Web Pages on the Internet. Also allows definition of data
forms which communicate with CGI compatible programs on the Internet.
HTTP
"HyperText Transfer Protocol". A communications protocol used by Internet Web Service
software to send Web Pages to Web Browser software over the Internet.
HyperText
A type of text document which contains embedded "hotspots" which point to other sections
of text or other documents. Any piece of text or graphic can be defined as a hotspot
which points elsewhere.
Internet
(a.k.a. "The Information Superhighway"). A world-wide interconnection between thousands
of computer networks on many different platforms, with over 10 million end users (and
growing). The telecommunications backbone of the Internet is based on a network of U.S.
government owned, national T3 lines. A growing number of Internet Providers are adding
their own backbones.
Internet Providers
A community of competing businesses which provide "on-ramps to the Internet". The largest
of these companies connect directly into the Internet backbone, or provide their own
national or international backbones. Examples of true Internet Providers: Netcom, UUNet,
CERFNet, SprintNet, and Spry. Examples of partial Internet Providers & partial
Information Service Providers: CompuServe, Prodigy, and America On-Line.
IRC
"Internet Relay Chat". A program or feature popularly used on the Internet by individuals
to chat with others, by typing and watching text-based dialog. Many topic specific IRC
channels have been created on the Internet by users. These channels form a sort of forum
for conference room discussion.
Newsgroups
A collection of forums which gather Email from Internet users about a specific subject.
The collected Email entries (known as news articles) can then be perused by all Internet
users. Some are simply for recreational discussions, while others may allow people to
form self-supporting user groups.
PGP
"Pretty Good Privacy" encryption. A protocol for using private and public key encryption
to secure Email and other Internet transactions.
TCP/IP
"Transfer Control Protocol / Internet Protocol". The network communication protocol used
by all Internet computers. Similar in function to NetBIOS, SNA, or Novell Netware's
IPX/SPX.
Telnet
A program or feature popularly used on the Internet by individuals to log into, and take
control of other computers on the Internet.
VRML
"Virtual Reality Markup Language" A new emerging language becoming supported by the World
Wide Web, for programming virtual reality content on the Internet.
Web Browser
A type of program used by individuals which reads HTML files on the Internet and presents
them to the user in a friendly way and interactive way. Many such programs exist for many
platforms. For UNIX several GUI browsers are popular. For those UNIX based terminals or
DOS based PCs, Lynx provides a text interface to browse Web Pages. All Web Browsers allow
the user to interactively jump from place to place by selecting hotspots (highlighted
text or graphics). Some browsers allow the user to print page contents.
Web Page or Web Document
A single viewable unit of Web information. Often be comprised of an HTML file with
several referenced graphics files. Generally, each Web Page has hypertext links to other
Web Pages.
Web Site
A collection of Web Pages built for or by a single company or individual. Usually
provides one theme of content. A Web Site is not to be confused with a single physical
location where a Web Server exists. It is a Cyber-Location.
Web Server
A combination of computer hardware, telecomm. lines, and HTTP server software.
World Wide Web, WWW, or The Web
An intricate and vast web of information, tied together by hypertext links between
multimedia documents residing on thousands of Internet computers around the globe.
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