Body Links To A Better Workday
Yes, there are inexpensive steps to a safe and comfortable computer workstation! Most people who study ergonomics agree there are three basic principles that should be followed when setting up a computer workstation. Can you ignore them? For a while. But sitting down daily to work for several hours cramped up into the wrong positions will not only limit your efficiency, eventually it will do long term damage to the muscles and nerves in your neck, shoulder, back, and wrists. But proper ergonomics isn't just about your health, proper ergonomics will help you type faster, work more efficiently, so you can get done and go do something a bit more enjoyable than sitting at a keyboard!
When applying these principles it is helpful to understand the concept of a neutral body position. This is a comfortable working posture in which your joints are naturally aligned. Working with the body in a neutral position reduces stress and strain on the muscles, tendons, and skeletal system and reduces the potential of developing repetitive stress disorders. Being “out of plumb” results is excessive muscle activation that can contribute to pain.The following are important considerations when attempting to maintain a neutral posture while working at a computer workstation:
Principle #1: Straight as an arrow.
The hands, wrists, and forearms should be straight, in-line and roughly
parallel to the floor. Think of a ruler being taped to the backside of
your wrists. If you are seated to high in relation to your keyboard then
your wrists will want to bend up into the ruler. If you think that is
uncomfortable you should try having lateral epiconylitis (tennis elbow)!
To get the correct alignment you should consider:
What furniture will you use?
Make sure that the computer monitor, keyboard and mouse are placed on
a working surface with adequate room for proper arrangement. If this work
surface is going to be used for writing on paper as well as computer,
use a flat surface that is between 28"-30" above the floor (suitable
for most adults). You should consider attaching a keyboard/mouse tray
system to your work surface. Choose a system that is height adjustable,
and one that allows you to tilt the keyboard down away from you slightly
for better wrist posture (negative tilt). The tray also should allow you
to use the mouse with your upper arms relaxed and as close to the body
as possible with your wrist in a comfortable and neutral position. __
Remember, if viewed from the side, a straight line should drop from your
shoulder down through the elbow when your fingers are resting on the middle
row of keys.
What chair will be used?
Select a comfortable chair that provides proper lumbar support by following
the natural curves of your back. The seat should be comfortable and allow
your feet to rest flat on the floor (or footrest). Your thighs should
be parallel to the floor or with your knees slightly below the height
of your hips. Armrests, if provided, should be soft, allowing your shoulders
to relax and your elbows to stay close to your body. If more than one
person will be using the computer, consider buying and a chair with several
ergonomic features and a wide variety of settings to adapt to different
user body types.
Studies show that the best seated posture is a slightly reclined posture
of 100-110 degrees NOT the upright 90 degree posture that is often portrayed.
In the slightly reclined posture the chair starts to work for the body
and there are significant decreases in postural muscle activity and in
intervertebral disc pressure in the lumbar spine. Contrary to popular
belief, sitting erect is not a relaxed sustainable position compared to
being slightly reclined.
Principle #2: Know Where to Look!
Your computer monitor should be placed: Directly in front of you. It
should also be facing you without being angled to the left or right. By
having your monitor centered directly in front of you your neck and body
will not be twisted when looking at the screen. This helps to eliminate
too much twisting and creating an imbalance in muscle extensibility in
the side of your neck.
At a comfortable height that doesn't make you tilt your head up or down
to see it. When you are seated comfortably, your eyes should be in line
with a point on the screen about 2-3" below the top of the monitor
casing (not the screen). Sit back in your chair at an angle of around
100-110 degrees (i.e. slight recline) and hold your right arm out horizontally,
your middle finger should almost touch the center of the screen. From
that starting position you can then make minor changes to screen height
and angle to suit. Research shows the center of the monitor should be
about 17-18 degrees below horizontal for optimal viewing, and this is
where it will be if you follow the simple arm extension/finger pointing
tip. If the monitor is too low, you will tip forward out of plumb line
alignment which will overload the muscles in the back of your neck that
are preventing further tipping. Likewise, if it is too high you will tilt
your head backwards and end up with neck/shoulder pain.
Also, irregardless of screen size, it is important to use the scroll bars
to ensure that what is being viewed most is in the center of the monitor
rather than at the top or bottom of the screen.
If text looks too small then either use a larger font or magnify the screen
image in the software rather than sitting closer to the monitor.
Even if you wear bifocals or progressive lens, if you sit back in your
chair in a reclined posture (with you back at around 110 degrees) that
is recommended for good low back health, rather than sitting erect at
90 degrees, and if you slightly tilt the monitor backwards and place this
at a comfortable height you should be able to see the screen without tilting
your head back or craning your neck forwards. Postural problems with bifocals
can occur if you sit erect or hunched forwards. When facing your monitor
you should also be facing the brightest window in your office. This will
allow you to minimize glare that can change your head position and overload
your neck.
If any screen adjustments feel uncomfortable then change them until the
arrangement feels more comfortable or seek further professional help.
Where do I put all this other stuff?
A document holder can be a very useful tool because it prevents excessive
forward bending in the neck which can place a lot of strain on neck muscles.
Document holders get paperwork off of the horizontal surface. There are
several different options that can suit your office set-up:
An in-line document holder sits between the keyboard/keyboard tray and
screen. It is aligned with your body’s midline so that all you have
to do is look down to see the documents and raise your eyes to see the
screen.
A screen-mounted document holder that can be positioned to the side of
your screen. It should be placed on the same side as your dominant eye.
A freestanding document holder can be positioned next to the side of the
screen and slightly angled so that it follows a curve from the side of
the screen.
Principle #3: Get up and move!
Regardless of how good your working posture is, working in the same
posture or sitting still for prolonged periods is not healthy. You should
change your working position frequently throughout the day. You can modify
these stresses by:
• Making small adjustments to your chair or backrest.
• Standing up and walking around at least once during every hour.
• Performing periodic stretches to your fingers, hands, arms, and
torso. View some basic stretches
For additional information we have reviewed the following web site and
believe it is a valuable source to any unanswered questions. Please visit
'HealthyComputing.com for more information.
Happy and safe computing.
