Adjustable Keyboards
What are Adjustable Keyboards?
An Adjustable Keyboard is a keyboard which
is capable of being adjusted to the
personal preferences of the
individual. Typically there are two
aspects of conventional keyboards which
adjustable keyboards modify by making what
is typically a fixed tool (a rectangular,
flat block) into a reconfigurable device -
'split' (or 'splay') and 'tent'.
What are the
Ergonomic Benefits of an Adjustable
Keyboard?
The first
ergonomic benefit is derived from the
introduction of a user-configurable
'splay' between the portion of the
keyboard utilized by the left and right
hand. By changing the angle from
perpendicular to the plane of the body
of the user to a splayed orientation, Ulnar
Deviation in the wrists when
typing can be eliminated with a
sufficient range of adjustment.
Now a theoretical line formed by the
elbow, forearm, through the wrist and
the middle finger of the user can be
perpendicular to the keyboard without
any twisting at the wrist.
The
second ergonomic benefit arises from the
introduction of a user-configurable
'tent' in the keyboard. By raising
the planes of both sides of the keyboard
and creating a 'thumbs up' posture, Pronation
of the hands while typing is reduced,
and can even be eliminated if the
keyboard is adjusted to a vertical
orientation.
The
third ergonomic benefit arises from the
common design requirement that
adjustable keyboards must be relatively
symmetrical, and as such lack a discrete
numeric keypad (typically opting for an
embedded
numeric keypad instead). This helps to address
the risk factor of Overextension
for the mouse.
NOTE: The 'feet' at the back of
many keyboards, while arguably a
user-configurable adjustable feature, do
not qualify those keyboards as being
classified as "Adjustable
Keyboards". This is because
deploying these feet will create a
positive inclination in the keyboard,
which leads to Wrist
Extension, and actually introduces
an inferior design element to the
ergonomics of the keyboard.
What are Potential Concerns when
Considering an Adjustable Keyboard?
The most significant concern when
considering an Adjustable Keyboard is
whether the current workstation can
accommodate the keyboard when adjusted into
the desired position. Often
Keyboard
Trays are too shallow to accommodate
an Adjustable Keyboard once it is
splayed. Sometimes
Keyboard
Trays will have a Wrist Rest which
will need to be removed to provide
sufficient adjustment space. Finally,
some non-height adjustable
Articulating
Arms may not lower sufficiently to
accommodate the vertical tent of an
Adjustable Keyboard.
Another consideration is the risk of
Wrist
Extension that is
caused by tenting the keyboard and failing
to provide a Palm Support to prevent the
wrists from 'dropping' off the now more
significant vertical profile.
Some ergonomic devices are not compatible with Adjustable Keyboards. For example, many Central Pointing Devices will not function well in conjunction with an Adjustable Keyboard. Certain types of
Writing Surfaces may also be incompatible in certain circumstances with Adjustable Keyboards (due to either their splay or their height).
Adjustable Keyboards help to reduce awkward
postures at the wrist. However,
depending upon the personal
Anthropometrics
of an individual, when one resolves issues
at the wrist, it may create new problems at
the elbow or shoulder. In these cases,
a
Separated
Keyboard may provide the answer.
For What Types of Tasks / Users are
Adjustable Keyboards Suitable?
While individuals of all levels of
keyboarding skill are suitable potential
users of Adjustable Keyboards, the split
inherent in this type of keyboard will force
users to become better typists as they will
find it almost impossible to type letters on
the left half of the keyboard with their
right hand, and vice versa. In this
sense, Adjustable Keyboards may assist
hunt-and-peck
typists along the road to becoming
touch
typists.
What Physical Injuries or Conditions
Typically Benefit from Adjustable
Keyboards?
Adjustable Keyboards can be of benefit to a
wide variety of users including individuals
with wrist conditions such as
Carpal
Tunnel Syndrome and
Guyon's
Canal Syndrome. Due to their
tenting capabilities, they also typically
benefit individuals with
Lateral
Epicondylitis and
Medial
Epicondylitis. As they also
reduce the amount of movement to use the
mouse, they are of potential benefit to
individuals with Rotator Cuff, Bursitis and
Cubital
Tunnel Syndrome.
