View
237
Download
0
Category
Preview:
Citation preview
УНИВЕРЗИТЕТ „ГОЦЕ ДЕЛЧЕВ“ – ШТИП
МАШИНСКИ ФАКУЛТЕТ – ВИНИЦА
СЕМИНАРСКА РАБОТА ПО ПРЕДМЕТОТ:АНГЛИСКИ ЈАЗИК 2
ТЕМА:REPETITIVE STRAIN INJURY
Ментор: Изработила:
Пом.асс.м-р Крсте Илиев Александра Атанасовска
Бр.на индекс:19251
Виница,2012
REPETITIVE STRAIN INJURY
Repetitive Strain Injury (RSI) is a potentially debilitating condition resulting
from overusing the hands to perform a repetitive task, such as typing, clicking a
mouse, or writing. Anyone who uses a computer regularly is at risk and should know
about RSI. Unfortunately, most people are uninformed and do not understand what
RSI is or how serious it can be. This webpage is intended to educate computer users
about RSI, and to provide useful suggestions for prevention and treatment. Much of
the information provided here is also relevant for RSIs derived from other activities
such as playing an instrument, gaming, or any other repetitive task. The page
additionally contains a few specific pieces of advice for students.
This webpage was written and is maintained by Clay Scott . I have formatted the site
as a single page in order to minimize clicking, and so that you can easily print the
page if you prefer. You may feel free to contact me if you have questions that I might
be able to answer. I have been living with RSI since 1997, so you will find a
sympathetic ear with me.
What is RSI?
In simple medical terms, repetitive strain injury (RSI) is defined as a
cumulative trauma disorder (CTD) stemming from prolonged repetitive, forceful, or
awkward hand movements. The result is damage to muscles, tendons, and nerves of
the neck, shoulder, forearm, and hand, which can cause pain, weakness, numbness,
or impairment of motor control.
You may wonder how seemingly innocuous activities such as typing and clicking a
mouse button could possibly be harmful. Fine hand movements, repeated hour after
hour, day after day, thousands upon thousands of times, eventually strain the
muscles and tendons of the forearms, wrists, and fingers, causing microscopic tears.
Injured muscles tend to contract, decreasing the range of motion necessary for
stress free work. The sheaths that cover delicate tendons run out of lubrication
because they aren't given time to rest, so tendon and sheath chafe, resulting in pain.
Due to this abrasion, tendons become inflamed, and begin to pinch neighboring
nerves. This can result in numbness, tingling, or hypersensitivity to touch. Unless this
cycle is interrupted, it repeats itself over and over, and a long-term, chronic problem
results.
Repetitive strain injury can affect more than just your hands and wrists. Poor posture
can lead to severe neck and back injuries. Staring at a computer screen can lead to
eye strain. Repetitive reaching for a mouse can lead to arm and neck strain as well
as spinal asymmetry.
RSI is not a specific medical diagnosis, but rather a family of disorders. Many people
mistakenly equate RSI with carpal tunnel syndrome, even though CTS is only one
particular form of RSI. One recent study even reported that frequent computer users
are no more likely to develop CTS than non-computer users. Don't let this mislead
you, though. Many other forms of RSI do come on as a result of frequent computer
use.
Who is at risk?
The three primary risk factors are poor posture, poor technique, and overuse.
These topics are discussed in depth in the section on prevention. In addition to
these, there are several other risk factors to be aware of. While they may not cause
RSI on their own, they can increase your risk if you already possess one of the three
primary risk factors. The following list (adapted from Pascarelli and Quilter) lists
several risk factors. You may be at risk for developing an RSI if you:
Have poor posture
Have poor technique
Use a computer more than two to four hours a day
Have a job that requires constant computer use, especially heavy input
Don't take frequent breaks
Are loose-jointed
Don't exercise regularly
Work in a high-pressure environment
Have arthritis, diabetes, or another serious medical condition
Keep your fingernails long
Have an unhealthy, stressful, or sedentary lifestyle
Weigh more than you should
Don't sleep well
Are afraid to ask for better accommodations
Won't accept that you are at risk when you really are
What are the symptoms of RSI?
The primary warning sign of RSI is pain in the upper extremities (fingers,
palms, wrists, forearms, shoulders). The pain may be burning, aching, or shooting. It
could be local (e.g., fingertips) or diffuse (e.g., the entire forearm). The pain will
typically be increased after a long session of computer use. Keep in mind, however,
you can have severe RSI without experiencing pain. The following checklist (adapted
from Pascarelli and Quilter), can help you determine whether you have RSI:
Do you experience:
Fatigue or lack of endurance?
Weakness in the hands or forearms?
Tingling, numbness, or loss of sensation?
Heaviness: Do your hands feel like dead weight?
Clumsiness: Do you keep dropping things?
Lack of strength in your hands? Is it harder to open jars? Cut vegetables?
Lack of control or coordination?
Chronically cold hands?
Heightened awareness? Just being slightly more aware of a body part can be
a clue that something is wrong.
Hypersensitivity?
Frequent self-massage (subconsciously)?
Sympathy pains? Do your hands hurt when someone else talks about their
hand pain?
In addition to these symptoms, RSI can also lead to behavioral changes. You may
not even be aware of these changes. For example, do you:
Avoid using the injured hand?
Use your nondominant hand more frequently?
Use your forearm, feet, or shoulder to open doors?
Avoid wearing or buying certain kinds of clothing because it is too difficult to
put them on?
Change shopping habits because you can't carry as much as he wants could?
Keep dropping things?
Find you can't chop food?
Not play sports you once enjoyed?
Have trouble hooking bras or putting on jewelry?
Not wear bracelets because your wrists are tender?
Have trouble with keys or brushing teeth?
Feel overly protective of your hands?
Repercusions of RSI
If you develop RSI, and do not take steps to correct the problem, there may
be serious repercussions. When my RSI was at its worst, I was unable to open
doors, prepare my own food, do laundry, drive, write, type, and shake hands. This
lasted for half a year. I was unable to type regularly for about three years. Many RSI
sufferers complain of similar problems. In addition to limiting your day-to-day
functionality, this decreased independence can cause a significant emotional burden.
RSI can limit your ability to perform at work. Recent Supreme Court rulings do not
view RSI as a disability, and hence, RSI is not covered under the Americans With
Disabilities Act. (Apparently typing is not a "major life activity," according to a
recent opinion authored by Sandra Day O'Connor, for those whose job requires
significant amounts of typing.) Therefore your employer may fire you if you are
unable to perform your job because of your RSI. The prospect of changing (radically,
in many cases) your profession is obviously a daunting thought. For students, most
universities are willing to make accommodations, but lost productivity due to RSI
could still delay your graduation one or two years. And once you graduate, your next
employer may not be as accommodating.
Preventing RSI
As with all health-related issues, it is wise to eat well, exercise, listen to your
body, and avoid destructive behavior. However, there are some specific precautions
you can take to help prevent the onset of RSI.
Why bother?
When you first notice symptoms of RSI, you have already done substantial
damage to yourself. RSI can take months, even years to develop, and you can
expect it to take at least twice as long to heal. It has been several years since my
RSI was at its worst, and even now I must limit my typing. Even if you feel no pain or
other symptoms of RSI, you would do well to heed the following advice for RSI
prevention, especially if you meet one of the risk factors outlined above.
Good posture is crucial
What is good posture? For our purposes here, good posture is when you are
seated in such a way that the effort required to work at your computer is minimized.
The following checklist identifies the proper way to sit in order to achieve good
posture:
Feet: flat on the floor
Knees: directly over feet, bent at right anlges (or slightly greater), with a
couple inches of space from the chair
Pelvis: rocked forward, sitting on the "sitz bones," with hips (the sockets
where your femurs attach) positioned no lower than, and perhaps slightly
higher than the knees.
Lower back: arched in, and possibly supported by your chair or a towel roll.
Upper back: naturally rounded
Shoulders, arms: relaxed, at side.
Neck: arched in, relaxed, supported by spine. Be careful not to hold tension in
back or under chin.
Head: balancing gently on top of spine.
There can be exceptions. For example, it's OK to shift your legs and feet around if
they get figgety, but be sure to always keep the spine neutral and the head balanced
above the pelvis.
Unfortunately, the above written description can be very difficult for some people to
actualize. Over the course of our lives, our bodies become so habituated to certain
patterns of muscle tension, that we are unable to accurately perceive ourselves. For
example, I may feel like my spine is in a neutral position, when in fact my lower back
has too much arch. Even if I were to show you pictures, that would not solve the
problem because (1) the difference between good and poor posture can be subtle,
and (2) even if I could perfectly describe proper posture to you, your brain may not
have the ability to accurately put your body in that position, because of the
aforementioned habitual patterns. One solution to this dilemma is to have a skilled
teacher re-educate you on postural awareness. This can be done by someone
trained in a form of "bodywork" such as the Alexander technique. Another strategy is
to regularly practice gentle yoga or other practices that enhance mind-body
awareness.
I believe that your posture at your workstation is the most important factor in
determining your risk for RSI. Moreover, in my experience, your chair is a major
determinant of your posture. I cannot overstate this. Sitting at a workstation entails
holding your body in a static position (described above) for long periods of time.
Holding yourself in this position puts strain on your muscles. The less support you
receive from your chair, the more strain is placed on your body. Therefore, it is
essential to have a chair that supports you as well as possible.
The key to a good chair is adjustability. A good chair will be adjustable in the
following ways:
Height of seat
Angle of seat
Height of backrest
Angle of backrest
Seat slides forward or backward
Arm rests move up/down and in/out
It is also important to have a firm seat, so that your pelvis can be firmly grounded,
but not too firm, so that your rear isn't killing you after a short time. Be careful to
avoid chairs with a bucket seat, i.e., a seat that makes your pelvis rock back. Tall
people will prefer a chair with a high backrest. A head/neck rest should not be
necessary, since your head should be balanced over your spine. Wheels are also
nice, if you have a carpeted floor, although wheels on a wooden floor may slide
around too much.
Unfortunately, it is virtually impossible to find a chair that fits you perfectly, even if
you find a chair that is fully adjustable in every conceivable way. I have found it
beneficial to use a towel roll wedged behind my back at the base of my spine. This
helps keep my pelvis in the proper position, which is the key to good posture.
Currently I use a support called TruComfort , which I have found to be very helpful. It
was recommended by my Alexander teacher.
Highly adjustable chairs can be expensive, costing several hundred, if not one to two
thousand dollars. I got my chair at a discount (and it was still expensive!) through the
ergonomic supplier for a company I interned at. Check with your employer's
Ergonomics Office, to see if you can receive a similar discount. If you can afford it, a
good chair is definitely worth the investment, and the higher the quality, the longer it
will last you. A well made chair should last 20 years or more. But be careful when
purchasing a new chair: many models say they are ergonically designed, but are not.
I recommend that before you buy a chair, you do two things:
(1) Use the chair for a week to make sure it fits you, and
(2) read Sitting at Your Computer .
If you can't afford a new chair, and if your employer will not provide one, you will
have to do the best you can with what you have. The towel roll can be very helpful in
this situation.
The next section is related to proper posture.
Setting up your workstation
There are three pieces of equipment that require special attention:
1. Keyboard: positioned above your thighs, you shoulder be able to reach the
keys with your elbows at your side and bent at (perhaps slightly greater than)
90 degrees, and your forearms roughly parallel to the ground;
2. Mouse: just to one side of your keyboard, so that you don't have to lean,
stretch, or hunch to work it. Many people have one shoulder noticeably lower
than the other - this can be caused by repetitive stretching for a mouse;
3. Monitor: directly in front of you (not off to the side), such that your eye level is
somewhere between the top of the screen and 20% from the top. The screen
should be about 15-25 inches from your eyes.
This last point is very important, but can be problematic if you only have one desk,
and like space to write. In this case, I suggest one of three possibilities: (i) Find
another place to write, such as the library; (ii) Get a cheap computer desk if you have
room in your office; (iii) Find a rolling or sliding tray to put your monitor on, so you
can move it aside when you need to write. If you don't position your monitor
correctly, it can lead to severe neck strain over time. For example, if your monitor is
too far back on your desk (or if your font is too small), you will have the tendency to
hunch forward and jut your head out, in a subconcious effort to see the screen
better. This leads to another key point: Don't use really small fonts! It leads to poor
posture and eye strain.
If you use a laptop, you will find it is vitually impossible to use good posture. This is
why I strongly recommend against the use of a laptop as an everyday computer. I
used a laptop all through college, and I know it contributed to my RSI. If you do most
of your work on a laptop, you really need to find a separate keyboard so that you can
put your laptop on a box or some books, and have your monitor at eye level. You
could alternatively find a separate monitor, but laptop keyboards tend to be too
small.
Proper technique: typing, mousing, and writing
There are three keys to proper typing technique.
1. Keep your wrists straight: the straighter your wrists, the less strain you put on
the tendons and nerves that run through your wrist. A split keyboard may aid
you in keeping your wrists straight.
2. Let your hands float: This means don't rest your wrists on the desk, keyboard,
or a wrist rest when you are typing. Let them hover over the keys. This has
three advantages: (i) You allow the big muscles in your back to share some of
the work; (ii) It allows you to keep your wrists straight, which is impossible if
they're planted on a wrist rest; (iii) It's easier to reach the hard-to-reach keys
(next item).
3. Don't strain your fingers: When you need to press a hard-to-reach key, like
CTRL, SHIFT, BACKSPACE, etc., don't stretch out your pinky. Instead, move
your whole hand and use your index or middle finger to press the key. Don't
use one hand when you need to hit two keys simultaneously, e.g. CTRL-X,
SHIFT-Y. Think before you type: unnecessary retyping/editting can add up.
Use a light touch when typing: don't pound the keys.
An ergonomic posture reminder that you can post near your computer was created
by Clemens Conrad.
There is another keyboard layout, in addition to the standard QWERTY layout.
Called the Dvorak layout, it was designed to minimize the movement of your fingers
as you type. In contrast, QWERTY was designed to maximize the amount of finger
movement, so as to avoid jammed levers in old mechanical typewriters. Most
operating systems allow you to switch your keyboard to this format (in Windows, try
Control panel -> Regional and Language Settings -> Languages -> Details). Some
ergonomic keyboards also allow you to to switch between QWERTY and Dvorak at
the touch of a button. When I switched to the Dvorak layout, there was about a
month of transition time where I wasn't able to type as fast as I used to. Now, I have
less pain in my hands than before I made the switch. You can find Dvorak typing
tutors online.
Using a mouse can be even more harmful than typing. Here are three reasons why
this is so:
All the work is done by one finger. Double clicking and dragging can be
especially straining.
Modern windows-based machines rely heavily on the use of a mouse.
Users often do not position the mouse properly. Instead, they stretch for the
mouse, which can lead to increased strain, a drooping shoulder, and pain
extending up into the shoulder and neck.
My solution for these problems has been to switch to a trackball . This has the
advantage that the mouse is stationary: you don't have to move your whole arm to
move the pointer across the screen, which reduces strain on the arm, shoulder,
back, and neck. It also has extra buttons, which can be programmed to double-click
or drag with a single click. Moreover, the work is more evenly distributed among the
fingers. Actually, I have two mouses. One is a trackball on the left, and the other is a
standard mouse on the right that I use for scrolling and moving but never clicking.
Standard mouse Trackball
Another solution is to use key commands to operate in a windows environment,
rather than the mouse. Once you learn the commands, this method is often faster
than mousing. A solution that will not work is switching which hand you use to click
the mouse. This may provide temporary relief, but soon your other hand will be as
bad as the first.
In addition to typing and mousing, writing can add significant strain to your hands. It
is important to hold your writing utensil lightly. Someone should be able to pull it out
of your hand when you are writing. It also helps to use a writing utensil that doesn't
require you to push down too hard. Ball point pens should be avoided. I recommend
soft lead pencils, or the Dr. Grip Gel Ink pen.
Stretching and strengthening
In this section I offer some specific recommendations for stretching and
strengthening exercises that have helped me. These fall under the category of
prevention as well as recovery. Most of them you can easily do in your office during
breaks, which you should take every hour or so.
Wall stretch: This is my favorite stretch. It is great for stretching out the shoulder,
arm, wrist, and hand all at once. Extend the arm along a wall, with arm parallel to the
ground and palm facing wall. Attempt to open chest so that shoulders are
perpendicular to arm. Extend fingers and palm away from wall as much as possible.
Your hand may tingle - this is OK. Hold for 30-60 seconds. Try with the arm at
different angles. Repeat on other side.
Doorway: This stretches the pecs and shoulder. Hold elbow at a right angle, and
place forearm along door frame, as shown. Lunge forward, keeping chest and pelvis
facing squarely forward. Hold 30-60 seconds. Try holding arms at different angles.
Repeat on other side.
Back and neck strengthening: The other thing I do that really helps is an exercise
that involves one of those big exercise balls, a long dowel rod, and a couple of 3 (or
2) pound dumbbells. You get on your knees, lay your chest on the ball, put the rod
on your back so that it makes contact with your rear, back, and head (to keep the
spine neutral). The ball should be big enough so that the rod is sloping slightly up.
Then just slowly raise the dumbbells off the ground and lower back down. You can
have the arms at different angles, but start with them extending behind you, as that
is easier. Also try turning your head from side to side occasionally as you go, to
activate the neck muscles. You do not need heavy weights for this exercise to be
effective, and heavy weights may in fact strain your already fatigued muscles.
Correct breathing: It's amazing how stress and computer use can corrupt our natural
way of breathing. I highly recommend Barbara Conable's short little book on
breathing called The Structures and Movement of Breathing: A Primer for Choirs and
Choruses . Don't worry that it is written for choirs, there's a lot of useful info for
everyone.
Eye palming: A relaxation technique for the eyes is to place your fingers crossed
over your forehead and cover the eyes with your palms. Do not apply pressure to the
eyeball. Just concentrate on the blackness for a while. Another simple but great
technique is to just look out the window at a distant scene.
The above exercises are primarly geared toward relieving/preventing the symptoms
of RSI. If you want to eliminate the root causes of RSI, you must focus more on
stretching, strengthening, and re-educating the core muscles of your body
responsible for maintaining proper alignment and posture. It is not possible for me to
explain how to do this here. However, there are several practices/techniques that
aim at this goal, including yoga , Pilates, the Alexander techique , the Feldenkrais
method , and T'ai Chi. You can probably find a group class in the $10-20 range in
your area if you live in a large city or near a University. Yoga and Pilates can also be
learned from books and videos, but it is usually better to learn from a teacher and to
practice with a group. Personally, I have derived benefit from yoga, Pilates, and
especially the Alexander techique .
Ten easy ways to reduce your risk of developing RSI
1. TAKE BREAKS! when using your computer. Every hour or so, get up and
walk around, get a drink of water, stretch whatever muscles are tight, and
look out the window at a far off object (to rest your eyes). As explained in
above,
2. Use good posture. If you can't hold good posture, it probably means it's
time for you to take a break from typing. If you are perpetually struggling
to maintain good posture, you probably need to adjust your workstation or
chair, or develop some of the support muscles necessary for good posture.
3. Use an ergonomically optimized workstation to reduce strain on your body.
4. Exercise regularly. Include strengthening, stretching, and aerobic exercises.
I find yoga and Pilates especially helpful.
5. Only use the computer as much as you have to. Don't email people when
you could walk down the hall or pick up the phone and talk to them. It's not
only better for your hands - it's friendlier. Think before you type to avoid
unnecessary editting.
6. Don't stretch for the hard-to-reach keys, e.g. BACKSPACE, ENTER, SHIFT,
CONTROL... basically everything but the letters. Instead, move your entire
hand so that you may press the desired key with ease. This is crucial when
you are programming or typing something in LaTeX, where non-letter keys
are used extensively.
7. Let your hands float above the keyboard when you type, and move your
entire arm when moving your mouse or typing hard-to-reach keys, keeping
the wrist joint straight at all times. This lets the big muscles in your arm,
shoulder, and back do most of the work, instead of the smaller, weaker,
and more vulnerable muscles in your hand and wrist. If you find it difficult
to do this, then your shoulder and back muscles are probably too weak. It is
OK, and in fact a good idea, to rest your elbows/wrists when you are not
typing.
8. Use two hands to type combination key strokes, such as those involving the
SHIFT and CONTROL keys.
9. When writing, avoid gripping the writing utensil tightly. Someone should be
able to easily pull the writing utensil out of your hand when you are
writing. If your pen or pencil requires you to press too hard, get a new one
(my favorite is Dr. Grip Gel Ink)
10.Realize that you are not invincible. RSI can happen to you. Don't be afraid
to ask for help.
Coping with RSI
An advanced case of RSI can cause a significant emotional burden. Because
of your limited use of your hands, you'll constantly be asking other people for help
just to get by in life. It can be quite challenging, for example, to ask someone you
don't know to give up their seat on the bus for you because your hands are too weak
to hold the hand rail. On the other hand, you will find that most people are willing to
help you out in your time of need. Take advantage of close friends and mentors who
would be willing to listen to your struggles, and help you sort out your feelings.
Universities often have Counseling Centers that are free to students.
Recommended