|More than 20 million American adults
complain of numbness and tingling symptoms, making RSI the #1 injury in
workplaces. With children now spending hours a day playing computer
games, working on school projects, RSI may be as likely to develop at home
or in the classroom.
Two areas that need to be addressed:
|First, we need to look at the simple definition of
ergonomics: Ergonomics is the study of fitting the workplace to
the worker (in this case, the child). This may be a problem in
the mismatch between a child's body size and the size of adult
furniture and computer equipment.|
|Second, children are learning unhealthy computer habits
early. These are then integrated into adulthood.|
Both of these factors lead to awkward postures which in adults would
be considered high risk activities to be eliminated. Usually, they
go unnoticed in children but they are fairly obvious if one takes a look
at some common postures of children.
Compare Adult Desk, Chair,
Keyboard to Child's Desk
Height of the Keyboard
Both adults and children should allow for forearms to be parallel to
the floor with elbows bent at a 90-110 angle.
This presents a problem at the adult desk; the child is
reaching too far up causing strain on shoulders, elbows and writs.
This can be accommodated by either:
|Bringing the keyboard down to the child's height on and adjustable
keyboard tray or lap cat (for children who are not wiggly) OR|
|Raising the child to the height of the keyboard (chair height or
pillows). This would require a box or support for their feet as
this dangling position may place strain on their low back and reduce
blood circulation to the legs.|
A child's desk is a better match to their proportions. The
child is able to hold the shoulders and elbows relaxed, with the wrists
in correct alignment.
Simply because an adult desk height was made to fit a range of
adults, the monitor at this height places it well above a child's eye
level, thus causing her to hold an awkward neck posture to look up at
the screen. Many times children will lean forward off the back of
the chair, arching their back in and raising their chin. This
places great strain on the neck and upper back as well as gives a poor
visual relationship. This is a red flag risk factor for adults
which we correct immediately.
At an adult desk the only way to correct for this is to raise
the chair, making sure that the keyboard height is in correct
relationship and that the feet are supported. Using a laptop
screen for older children may bring the monitor height down just enough.
Also tilting the screen downward will have a lowering effect. This
does make the eye open more at this angle, causing a little less
protection from the eyelid for glare and dryness. There are
manufacturers (Kinderlink, Metamorphosis) which make adjustable
keyboard/monitor tables which can be adjusted to the child and adult.
At a child's height desk, this risk factor is reduced. The
height is matched to the child's size and they are able to look at the
top of the monitor at eye level.
Again, we are looking at fit and proportions. When using
a shared adjustable chair, you can teach your child to quickly adjust it
to their fit. Raising the height, bringing the backrest in to take
up some seat room and lowing the back support. There are some
manufacturers that make chairs in various sizes, some of the small and
extra-small adult chairs would fit older children.
When using a kitchen chair, a lumbar support may be placed in the
chair to make it smaller and ones with sides will give children good
lateral support and trunk stability while they sit. Also pillows
and phone books may be placed in the chair to raise the child to the
Keyboards and Mice
Look at the difference in hand size, finger length and span. An
adult keyboard was engineered to fit a range of adult hand sizes.
Some potential solutions may include.
|Using a smaller keyboard, where the numeric keypad and arrows are
deleted. This allows for closer mouse placement. The
result is a child does not have to strain their shoulder to reach the
|Little fingers keyboard (data desk) was designed with little hands
in mind. They have reduced the actual size and spacing to match
a child's finger size and reach.|
|Keyboard track balls and touch pads also reduce the shoulder
|Mice now come in various shapes and sizes; using a smaller size to
accommodate a child's hand size is best. Placing it at the same
height and close to the keyboard is important.|
The good thing is that children are seldom completely still.
The constant motion of their shifting weight in the chair and standing
then sitting can be to their advantage. However even still they
can become so attentive to the screen that they can fix in unwanted
static postures which latter become adult bad habits.
|Wrist leaning. This causes compression of the median nerve
through the carpal tunnel. Teaching children proper typing
position and techniques should not be lost or put off until high
|Elbow and forearm leaning to see the screen. This places
strain on the shoulder joint capsule. Teaching them proper
posture now is important.|
|Improper mouse grip. Relax mouse grip with neutral or
Because more and more children are spending an increasing amount of
time in the seated posture whether it be watching TV or working on the
computer, they are inherently getting less exercise. What we may
begin to see are children with tight hamstrings and weaker abdominal
muscles. These muscle groups should be stressed early on.
This can be accomplished by:
|Simple abdominal work such as ball exercise and traditional
As far as computer exercises children can relate to their favorite
athlete. No Washington Redskin or Baltimore Oriole takes the field
without warming up. Teaching children warm-up stretches and
periodically repeating them while they are on the computer will allow
their muscles to work more efficiently. None of these should cause
pain or discomfort:
|Back extension, especially for those that sit with slouched
Please call or email us for further questions or
ERGOWORKS Consulting, LLC
Phone: (301) 417-2077