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What is RSI?
Medical description op RSI
Medical explanation of RSI
Most occuring complaints
History
Incidention / prevalance
Recognition / recognising RSI
Factors that influence RSI
Guideline for the workspace
Working circumstances that lead to RSI
Mind and Behaviour
Recovery
Conclusion
In medical terms RSI is being described as ;
'RSI is being caused by a number of factors, its an accumulation
of
psychomotoric, biomechanical, mental and emotional demands upon
the body
where upon the patient reacts with an inadequate movement strategy.
The
inadequate part consists in the employment of higher levels of
simultaneous contraction (cocontraction) of agonists and antagonists,
with
the purpose to keep the natural neuromotoric staticness of movements
filtered through the enhanced stiffness and thus keep within limits.'
(van Galen Yearbook Physiotherapy 1999)
Medical explanation of how RSI originates;
RSI doesn't really occur because the work is too heavy, but moreso
because
the performed actions are being repeated continiously, often on
a high
speed, in a static position. This means that the person concerned
often
moves very little, is slightly tensed and performs the same movement
often, with precision. Not only the regular mouseclicking causes
RSI, also
the typing on a keyboard is a repetitive labour.
To be able to perform with precision it takes a simultaneous tension of
muscles with opposite functions (cocontraction) and static load. By means
of this cocontraction the bloodcirculation is severely pinched off.
Investigations show the bloodcirculation can diminish by 80% under the
influence of cocontraction. This means the muscles only get one fifth of
the normal amounts of oxygen and nutrients, while constantly labouring,
sometimes hours on end. Owing to the decreased circulation waste material
and nutrients can't be exchanged properly, resulting in an accumulation of
waste material in the involved parts of the body. Small inflammations of muscles,
sinews and nerves start to occur. This is where complaints about pain start.
The same process happens to top-class athletes, by whom the muscles acidify
and start hurting after a longlasting performance. With the first symptoms of
pain the muscles often get more tensed, as a result the bloodcirculation stagnates
even further. More waste material piles up. Thus begins a vicious circle of
accumulation of waste material, more pain, etcetera. Once started, this circle
is hard to break apart and can upkeep or worsen the complaints. This can further
lead to a variety of symptoms on the neck, back, shoulders, arms, hands and fingers.
Because of the many ways the complaints manifest themselves, the comparison of
RSI-complaints is difficult. Not only people who work with computers can get RSI;
musicians, sportspeople, construction workers, hairdressers, conductors, surgeons
etcetera, are part of the high-risk group. Physiological, biomecanical, ergonomical
and physical factors influence obtaining RSI ; they contribute to a higher
cocontraction.
(see furtherdown, in reference to the factors contributing to obtaining RSI.)
Most occuring complaints are;
- headache
- cold hands and feetswellings and
lumps under the skin
- change in skintone
- less able to relax, increased muscle
stiffness
- muscle cramp
- a feeling of tiredness/heaviness
- cramped poses
- loss of function to impossibility
to perform daily acts (advanced stadia)
All these complaints can occur in neck, back, shoulders, arms, wrists,
hands and fingers.
Some people may wonder how such an abundance of symptoms can be possible.
As mentioned above, pain is often one of the first symptoms. This pain
stands in relation to the inflammationproces. The symptoms that occur with
inflammation are pain, redness, swellings, warmth. Eventually it's even
possible that the body is no longer capable of performing certain
movements. This is also seen when you have a wound that gets infected. If not given
time and rest, to heal, it will only get worse. Besides the muscles and
tendens the nerves also play a part in the symptoms that can show up with RSI.
The nerves for the arms orginate in the spinal cord between the shoulderblades.
From there they go in bundles to the upperarms, where they split in 3 nerves for
the different parts of the arm.
Nerves can get opressed locally by infections, but also because of the way the
joints are positioned. For example ; when the angle between hand and forearm is
being diminished when using a mouse this can cause too much pressure on the
wristjoint. This excessive pressure on the nerves can also occur centrally at
the spinal cord, caused by the way the head is angled on the neck and shoulders.
The vertebra are connected with eachother like a vacuumcleanertube.
This means if the head is not kept in a neutral position (facing straight forward)
it will influence the rest of the joints of the spinal cord, narrowing the space
through which the nerves leave the spinal marrow, and a hightened pressure will
occur on the nerves. If the nerves are opressed in such a manner the stimulus
between the central nervesystem (brains and spinal marrow) and the periphery
nerve-system (for example the nerves in the arms) are not exchanged properly.
This can express itself in oversensitive reactions, loss of strenght,
feeling of deafness, tingling sensations.
The diversity in the symptoms can be explained by the different parts of
the body used when working on a computer (neck, back, shoulders, arms,
wrists, hands and fingers) and the underlying connections of these parts
of the body, and the infectious reactions that can show up in the
different structures. (tendens, muscles and nerves)
History
In spite of the fact that RSI is more and more wellknown, it certainly
isn't a typical modern day disease. There are very early mentions of monks
with 'writerscramp' when copying books, and from office clerks in the past
centuries.
Writerscramp is not a modern complaint, and is in many ways similar to the
modern, as RSI catagorised painsyndrome. The fact that the spreading of
RSI from the seventies on took hypelike forms, is most likely due to
repetitive use of the arms and hands, with the onmarch of wide spread use
of computers. Also the society on the whole is more prepared to take the
complaints of employees more serious.
Incidention / prevalance
It is estimated that as much as 30 % of all screenworkers have minor
complaints on neck, shoulder, arms, wrists, hands or eyes while working.
RSI is now a major cause for absence through illness in business
community, through which the costs for this problem runs in the billions.
Recognition / recognising RSI
Most people think before they get RSI, that it will never happen to them.
When the first complaints arise, they are often not very clear, and the
complaints get ignored. Only every now and then you'll have some
complaints, and they go away as soon as you stop with your daily work.
Under these circumstances people often go on for a long time, withouth the
pains getting any worse. This stadium can last for a long time. All of a
sudden the complaints get worse, because it's just been too much for too
long. Often this doesn't even have to do directly with working behind the
computer, but because of other stressfull factors in your life, like
you've just bought a bouse, you're about to have a baby, somebody close to
you died, and so on.
The pressure gets too much and it seems that the complaints sudden arrive
out of nowhere. Only then you notice how bad it is, but often you'll have
had minor complaints over a long stretch of time. RSI can thus be
described as a slow slumbering process, that can all of a sudden flare up,
often influenced by external factors. It is of the utmost importance that
The disease gets recognised in an early stadium, because then it is easier
and quicker to cure. In that stadium it is not yet a cronical pain
problem. Once people have damaged their tissues, they are always at
greater risk for reinjury or chronic bouts of RSI. It's far better to take
preventive action before it's too late!
Factors that influence RSI
In spite of the fact there has been a lot of research concerning RSI, it
is still not clear excactly what the underlying mechanism is that leads to
getting hold of RSI. It does seem clear that there are a number of factors
can contribute to RSI and explanatory models can be thought up now.
- Body factors
Still it is not clear what happens excactly in the body, that gives RSI
the chance to develop. On the other hand it is not contested that RSI is
not only being caused by the equipment used. Only the fact that next to
the employees that have RSI, there are more employees that don't have any
complaints, is a clue that also personal factors play a influential role.
the following physical factors are of influence in getting RSI :
- General poor moving
Just sitting at a desk is inherently damaging to your muscles and bones
because the body was designed to move. check the ape-people that only sat
for very short periods of time and where always on the move.
The human body must move to remain in optimum health, but the computer
virtually encases people in an invisible straitjacket. Holding muscles
still for long period of time (static movement) causes discomfort and
fatigue. The unvarying rigidity of sitting with the arms extended, staring
straight ahead for hours on end, exhaust the body.
In medicine, if someone is referred to as 'deconditioned', it means that
the person is out of shape. Most computerworkers don't get enough
exercises or sports. If you don't move vigorously on a regular basis, the
circulation slows, and the soft tissue don't get the nutrients it needs
from the blood supply. You feel stiff and sore. Noxious waste by-products
of broken-down cells are not carried away through the bloodstream, and
they settle into scar tissue, which binds muscle groups together, making
them work too hard. It became obvious that the people who are most at risk
have inadequate conscious/unconscious feeling over their own movements.
Too little physical exercise makes people with a hightened RSI risk work
too liong in unfavourable positions and thus get bloodcirculationproblems
and therefrom damage their muscles and nerves.
- Bad posture
A good sitting posture is an important factor. Posture is a dynamic
concept: it means keeping bones aligned though movement and stillness,
with muscles at their optimum length instead of too tight or overstreched.
This balances use of muscles affords ease of movement and freedom from
pain. It is often seen that people try to have a good posture by sittig up
stiffly, but this has the opposite effect. Sitting exhaust the body
because the back, leg and trunk muscles must contract constantly to keep
the body erect en still. The arms must be kept in a forced position on the
keyboard. Keeping the head vertical is a strenuous act; muscles of the
neck and shoulders must work to keep the head at the top of the vertical
spine. This is like balancing a heavy bowling bowl atop a series of
loosely jointed thread spools, causing longlasting stretching and pulling
to neck and shouldermuscles. Through this posture hightened cocontractions
of muscles and stiffness develop, with all the consequences..
- Movement strategies
To stay healthy, the body must move in a balanced way that allows full
range of motion, but most computer jobs require excessive upper-body
immobility, while the tendons and muscles of the forearm, hands and
fingers overwork.
Also movements develop with longlasting static cocontractions and
excessive cocontraction. Because of the hightened cocontraction. that
leads to a greater stiffness in arm, hand or fingers, the precise
movements can be made, control of movement is kept. (through which
somebody is capable of typing on a computer)
Both overuse and underuse of parts of the body (cocontraction and static
burden) cause a disbalance in the movement of the body and can lead to
physical complaints.
- Anatomy
Not everybody is built the same way, even between the individual parts of
the body there are anatomic variations. Most people have two different
sized feet, or both shoulders are slightly differently angled. Small
anatomic variations can lead to more friction on the muscle-tendens
combination, or there might be less space for structures, through which
imflammationreactions of muscle/tendens can occur a lot quicker. This
means that some people can get RSI much quicker than other people. One of
the anatomic variations that is in all probability also connected to
getting RSI more quick is the restrictment of movement in the back, mostly
the part between the shoulderblades.
- Ergonomics
Investigations have shown that the
ergonomics of a workspace are not a
explaining factor with patients with acute symptoms. This doesn't
mean a
ergonomical bad workenvironment is not a pressuring tax, and therefore
the
posture should stay an important fact to be given attention. What
can be
said clearly about the RSI-problem is that it comes from an accumulation
of factors, and is not to be attributed to one factor only.
For the prevention and cure of RSI all the factors that contribute
to RSI
have to be influenced as optimal as possible.
In literature, there are different schools of thought over good
RSI
preventing chairs. But for the human body, there is no chair where
one can
sit seven hours a day, not even in the best of all chairs. It
is also
clear that there is no such thing as a good sitting posture. The
conclusion is that big investments in ergonomical improvements
not always
lead to a reduction of symptoms. Investigators have performed
tests on
several ergonomical adaptations. These tests show that the hardware
does
indeed have an influence on the body posture, but most effects
of
ergonomic adaptations where simoultaneously positive and negative.
By
using this kind of adaptions you get a sort of shifting of the
problems,
and the pain also shifts to a different part of the body. It is
good to
realize that you don't tax your body any less if you tax another
part of
your body ! Somebody that always uses a mouse with the right hand,
gets
RSI pains, and continues with the left hand, runs the risc to
obtain RSI
complaints in the left hand. At the time the problem will be solved,
but
on long term there will be a bigger problem ; two arms with RSI..Even
if
you use voice-recognition excessively, you can get voice-troubles!
Guideline
for the workspace
Chair.
The correct posture is different for everybody. In general it
can be said
that one should try to sit with a straight back, head above the
hips, and
the lower back supported by means of an in hight adjustable backsupporting
chair. The sitting height at the front of the chair runs to the
hollow of
the knee, and the back of the chairseat is slightly higher (10-20
degrees). The hips make an angle of approximately a 100 - 110
degrees with
the upper body. The chair should be adjustable in height, so the
knees can
make an 90 degrees angle. A chair that can turn and has wheels,
gives more
freedom of movement. It is advisable to adjust the chair for each
person
individually, and not only by the guidelines, but also according
to the
feelings of the person involved. Not everybody is built the same,
remember..
Monitor.
The distance to the screen is dependable on the size of the screen
and the
state of the eyesight of the person involved.
Plus or minus these guidelines can be used ;
14 inch: 50 - 70 cm
15 inch: 55 - 75 cm
17 inch: 60 - 85 cm
19 inch: 70 - 95 cm
21 inch: 75 - 105 cm
The screen should be on eye-height and straight in front of the
person, so
the neck doesn't have to be turned towards the screen. It should
be
prevented that the head has to move forward every time, just to
be able to
read well. People who have impaired eyesight would do well to
wear
glasses, so they can keep the head in a straight position, without
having
to lean forward.
Desk.
The desk should be on belly-button level, arms pointed forward
slightly in
relation to the upper body, without drooping the shoulders. The
keyboard
placed half an armslenght from the edge of the table, so the arms
can rest
on the desk. the elbows make a 90 degree angle. The working space
should
not be too full of stuff, and should be big enough to have all
the
necessary things for work on it. It is important to have enough
space
under the desk, so that the legs do not have to be strangely angled.
For
people that are too small to put their feet flat on the floor
it is
sensible to have a footstool.
Keyboard.
Numerous ergonomic keyboards have been developed. Unfortunately
only a few
are really ergonomically compliant. As a general rule, mainly,
the
keyboard should type lightly, because pressing heavy keys hightens
the
tension of the muscles. The wrists should be kept in neutral position,
no
hanging or turned inwards, nor outwards. When typing, the whole
arm should
be taken from left to right. Not just the wrist should be bent
sideways,
because this causes a wrong taxation on the wristjoint.
Finaly.
It is fair to conclude that there are some general ergonomic rules
to be
stated through which the taxation of the sitting posture and screenworking
can be as minor as possible, or well balanced. The guidelines
are a good
guide to equip a workspace. The workspace has to be adjusted for
each
person individually, bearing these guidelines in mind.
Working
circumstances that lead to RSI
Not enough workbreaks
With too little breaks, there will
be long periods of uninterupted muscle
tension. It would be best to have mircobreaks every now and then,
so the
muscles get a chance to relax for a while. There are software
programs
that can automatically engage microbreaks. See the links on our
website.
Next to the microbreaks, it is sensible to have longer breaks
regularly,
just stand up for a while, and do something else, like chatting
to a
collegue, have lunch, fetch coffee. The best thing would be to
have breaks
where a couple of stretching excercises ar done, so that the muscles
get
stretched, the body parts are moved, and the bloodcirculation
gets
stimulated so the excess waste material can be exchanged with
fresh
oxygen. See our videofilms on our website, showing the excersizes
that can
be done to prevent RSI.
Working long time in the same position
Recoveration can be obtained by shifting
work positions, changing the
work, especially the work that has to be done on maximum speed
with great
accuracy.
To much workpressure
People are routinely hired for typing
speed (which is fallacious thinking,
because 'slow' typist may actually produce just as much work if
faster
typist take lots of breaks). A person whose pace is naturally
slower has
to strain up to keep with fast person's pace. But not even fast
typist
should work at top speed every minute of the day. There's a natural
rhythm
to work: now fast, now slow, now take time to stop a moment and
chat with
a co-worker. If this rhythm isn't respected, the muscles fatigue;
if they
are not allowed to rest and recover, they become damaged.
Incentive programs that link bonuses with speed and productivity
are
especially dangerous. Many people severely themselves by pushing
beyond
their body limits in order to make money. Overtime can be dangerous
too,
because it further taxes muscles that are already tired and overused.
Unfortunately, a lot of people are forced to work extra hours
in order to
make ends meet. You will also notice that under high pressure
working
circumstances you will not notice the sagging or tensing of your
shoulders. On top of that you will ignore pain because 'the job's
gotto be
done' and you will make a final effort to finish the job. The
effect ;
further muscle tension with all the consequences.
Stress
Under the influence of stress the
muscles will contract even further,
therewith diminishing the bloodcirculation, and complaints will
occur. In
a physiological way it can be said that a stressed person can
react with
an oversensitive reaction in a certain musclegroup. All movements
and thus
stimulus that are given by the muscles lead to a vicious circle
of
tensing, circulationproblems, etcetera. Stress also makes the
central
nervous system ( the brains and the spinal marrow) oversensitive,
so that
the stimulus that arrive there give another fortification to this
vicious
circle. Stress can occur with too much workpressure, bad organising
of
work, lack of focus or control, unclear tasks, but also environmental
factors like noise, arguments with collegues, or not much job
satisfaction
How people feel about their work can have a powerful effect on
their
health. If they feel good about it, they are less prone to stress-related
disorders even is they have a relatively high
stress load. If people don't feel good about their work, the opposite
can
be true: they will get physical complaints much quicker. Besides
that, not
only stress through working circumstances can lead to RSI, also
stress
from external circumstances can contribute to RSI. See
recognising/recognistion RSI)
Bad ergonomics workspace (see ergonomics)
Mind
and Behaviour
Only in about 10 percent of RSI cases there is obviously demonstrable
disturbance, like for example 'carpaaltunnel' syndrome, tenniselbow,
frozen shoulder, etcetera. In the rest of the cases there is no
visible
objectiive deviation and nothing deviating can be found in the
muscles or
tendens of hands, arms, shoulders, back and neck. However it is
clear that
there is still to little insight in RSI, perchance in the future
there
will be a physical factor visible that will explain this disease.
The lack
of insight doesn't mean RSI is psychological, this is a rumour
that goes
around quite a bit.. It's obvious ther is a psychological factor
that
influences RSI. Though it's though to conclude what the cause
and effect
is of this player. there is no proof that psychopathological deformations
occur with RSI-patients. However often it has been found that
RSI-patients
are more worried, have a slight tendency towards depression, don't
sleep
so well, and more often seek the cause of the healthcomplaints
with
themselves. But investigations clearly show that RSI is just between
the
ears. Any serious illness can unleash a tempest of emotional reactions,
and RSI is no exception. Psychological reactions can result from
the
injury: because they have been injured, people feel angry; because
they
can no longer use their hands, they feel frustrated and impotent.
It's
natural that if all of a sudden you can't lift a cup and somebody
else has
to do the laundry, that this causes quite a bit of stress. A lot
of people
get depressed, thus slowing down the healing process.
Recovery
When people go to see a doctor after a period of having complaints,
and are
diagnosed as having RSI, many feel relieved to hear what was going
on.
Often they think that some days not sitting behind a computer
will relieve
them of all their complaints. Don't be mistaken! Recovery takes
a lot more
time than this!
The human body constantly regenerates itself. Cells age and die.
The body
produces new cells to replace them.
The time it takes the body to replace a cell is called, obviously,
the
replacementtime.
The replacementtime varies for different kind of cells. For instance:
the
cells of our digestory tract are the fastest to be replaced, in
a period of
only 36 ours the mucusmembrane has had a total makeover!
When RSI-complaints exist for prolonged periods of time, the lowered
bloodflow and contiuous buildup of wasteproducts will lead to
stuctural
change in the connective tissue of the muscles.
The replacementtime of connective tisssue is about nine months!
With severe RSI-complaints, the recovery period will take many
months, even
in the case of optimal treatment and a complete stop of work.
After recovery the affected musclegroup will not cease to be a
vulnerable
spot and complaints can easily reoccur, when restarting work.
Concluding, I would like to state that RSI is a very serious problem,
and
it is of the utmost importance to be alert at the first occurrance
of
complaints, and act accordingly. Preventive actions of RSI, of
couse,
are much preferred.
Conclusion
No exact definable cause of RSI is
yet proven. The multitude of factors
contributing to the occurrance of RSI, make it difficult to provide
a
simple answer to the question which therapy is most beneficiary.
To properly intervene a full understanding of all underlying causes
is necessary.
Yet it is proven that the simultaneous occurrance of the factors
involved
enhance the chance of getting RSI.
So, to prevent and treat RSI all possible causes contributing
to it should
be taken into account, and attended to accordingly.
At any rate, instruction and advice can help reduce complaints,
and
enhance awareness with the patient.
(C)2001 RSI2001.ORG
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