Split Keyboards or Music Conductors?
It’s Your Money!
by
James R. Seils, CSP, CIE
It’s incredible how many people are working in
pain at their computers these days. Yet rather than having an ergonomics consultant define
what the real problems are and create a solution that addresses all the issues, more often
than not they throw money at the problem by buying something off the shelf they’ve
seen advertised with the name ergonomic somewhere attached to it and assume from the
marketing hype that the problem will disappear overnight.
Like a shot in the dark, sometimes this works, but
most times it only temporarily addresses the symptoms while creating additional problems
and aggravating existing ones.
Keyboards
All too often people buy ergonomically designed
keyboards to address pains they already have from the way they work and the way their
workstation is setup. After buying the keyboard all they do is plunk it down on a
desk that has not been configured for their unique anthropometry and wonder why not only
hasn’t the problem been corrected, but why new pains now exist that did not exist
before. Rather than asking why the problem exists in the first place, they jump to
their perception of a solution which may be totally incorrect.
Problems with Ergonomically Designed Split
Keyboards
Whether right or wrong split keyboards have
become the solution du jour for many people when they begin experiencing hand-wrist pain
on a regular basis. These keyboards, which may be adjustable or fixed, have keys on
separate panels that form an inverted V between them. There are a number of keyboards on
the market today with this design, but there is no statistical evidence they do what all
the advertising and marketing messages say they do. In fact, to the contrary, they
can create new problems not previously noted.
The primary purpose of an ergonomically designed
keyboard is to place the hand-wrist-forearm in a neutral (straight-line) position and
generally keep it there during the time key stroking is done on the keyboard. The
purpose of a split keyboard is to specifically address the problem of ulnar deviation of
the wrist (movement of the wrist in the direction of the little finger), which has
previously been identified as one of the possible reasons carpal tunnel may occur.
One of the problems with the split keyboard
arrangement is that using it requires your arms to be abducted (moved outward from the
sides of your body), which places significant stress on the upper arms, shoulders, and
upper back muscles. Think of it this way... every part of your body has weight, and when
you move your arms away from your side (neutral), the upper back, shoulder, upper arm
muscles, and the elbow must support the weight of your forearm, wrist and hand while they
do work. The farther away you move any object from your body (distance), the greater
the load that must be supported.
Consequently, while you may be lessening the
possibility of carpal tunnel by reducing the potential for ulnar deviation of the wrist,
you are creating a higher probability for tendinitis or other cumulative trauma disorder
(CTD) in your upper arm and shoulder, or upper back disorder, which are problems that may
not have existed before.
Another issue of concern with the split keyboard
relates to potentially excessive use of the thumb in an unnatural up and down movement
pattern on some keys that have been repositioned on the keyboard to accommodate the
inverted V shape. Since the thumb is normally used in grasping type functions, the
prolonged use of it for activities that require tendons to perform this up and down
repetitive motion raises serious questions about the long term efficacy of this keyboard
solution. Tendinitis in the thumb or forearm is another of the many insidious
CTD’s that can occur.
Exacerbating the Problem with a Positively Sloped
Keyboard
The potential for upper arm, shoulder, and
back fatigue increases the longer this abducted arm position is held. For those
doing constant keyboarding, this will impact them directly. As your arm muscles fatigue,
your forearms will naturally drop.
If your keyboard is sloped positively, (meaning you
have the feet on the back of the keyboard propped up) you are going to increase the amount
of wrist extension (bending of the hand up at the wrist) that exists. This is bad
because when the wrist is extended forces on your tendons are highest, and it is precisely
these forces which raise the amount of pressure on the median nerve inside the carpal
tunnel, thereby compressing it.
Since carpal tunnel results from repeated
compression of the median nerve over time, using a split keyboard setup with a positive
slope actually increases the probability of injury.
Anthropometry Considerations
People do not give enough consideration to
the role anthropometry plays in all areas of a workstation’s setup, to include
choosing a keyboard. Compare the average hand size of a six foot or taller man with the
average hand size of a five foot woman and you will see a major difference in
anthropometry. Yet how many companies give all their employees the same size
keyboard because it was the one that came with the computer?
One of the primary candidates for ulnar
deviation problems are people who have smaller hands and a longer than average reach to
the keys farthest away from the center of the keyboard. Since force, posture and
repetition are the key ingredients defining whether a CTD may occur, the relationship of
the size of someone’s hands to the size of the keys and their spacing on the keyboard
are as important as the layout configuration.
In this situation one solution to consider is
finding a keyboard with smaller size keys that are slightly closer together and better fit
the hands of the specific user. While neither this nor any other solution is
absolute in remedying all problems, it has certainly more validity than just buying a
split keyboard... on the assumption that the keyboard is setup in concert with all
anthropometry considerations of the user and all items in their workspace, from their
chair to the angle of their computer screen.
Negatively Sloped Keyboards
Much has been published over the past two
years on negatively sloped keyboards, particularly the research work Alan Hedge has done
at Cornell/Honeywell on this subject. While most who are familiar with his findings
recommending a negatively sloped keyboard preset tiltdown system, few are familiar with
the many other benefits derived from this setting. Results from his study showed
significant improvements in seated body posture, and reduced musculoskeletal discomfort,
in addition to reduced wrist extension. Yet the proportion of companies that have invested
in this equipment is very small.
The Bottom Line
Good orchestras produce great music not just
because they have talented musicians with good instruments, but because a well schooled
and experienced conductor effectively integrates all the pieces to produce a great sound.
The conductor knows how to make each uniquely talented individual realize his full
potential by having him correctly use his instrument to create a desired effect.
Each employee is talented with his own unique
skills. Without direction though, he cannot perform at his peak no matter how much
ergonomically designed equipment he is provided. Unless someone experienced in
analyzing and setting up their workstation integrates all the pieces to produce not only
an efficiently designed environment but one that is pain free as well and, most
importantly, trains the employee and validates an acceptable level of understanding by him
of use of all the equipment, money spent is more often than not money wasted.
Just as training is important for the members of the
orchestra to learn to play together, so is training important for each employee who needs
to understand how to use the equipment he’s been given, but alas, this is often the
forgotten element. When decision makers say it’s too expensive, ask if they
know how much lack of proper training is costing them and you’ll usually end up with
blank stares.
With the average carpal tunnel claim now accounting
for 30 lost time work days according to the most recent NIOSH statistics, isn’t it
time to stop relying on the marketing hype and investing in a knowledgeable and
experienced conductor?
There are many different types of keyboards on the
market today, some with the designation as being ergonomically designed, and many others
with no such claim. Some of them, when used properly, for the right reasons, and in
concert with a complete orchestration of all the elements that make up a person’s
working environment, can provide a pain free, efficient work space that results in the
most productive employee possible.
If employees are one of your greatest resources,
then maximizing their performance will allow you to realize a tremendous return on your
investment. Ergonomic consultants should be viewed as value adders to both your
employees’ performance and the profitability of your bottom line. If you want
your workers to perform like finely honed members of a great orchestra, both they and you
need the direction of the right conductor.
You decide. Split keyboards or music conductors?
It’s your money! |
