Is there such a thing as an ergonomic light touch keyboard?

14th October 2014  •  1 comment  •  Posted in Ergonomics, Mobility issues, RSI

I frequently get asked by customers with Repetitive Strain Injury for a “light touch” keyboard.  Generally people with RSI start experiencing pains in their wrists or knuckles and feel that if only they didn’t have to press their keyboards quite so hard, it would help.

There are a number of factors to consider here:

  1. Virtually all keyboards have a certain amount of resistance in the keys.  Without that resistance the keys would just stay down and not return.  The “actuating pressure” can be measured (although it is quite difficult) and it would be nice if we had such figures available based on a standardised measurement technique for all keyboards.
    Unfortunately, since there are no internationally recognised standards for measuring actuating force, any figures quoted by manufacturers would probably be inconsistent and hence highly suspect.
  2. Even if a keyboard had what could be classed as a “light touch”, if you were to press too hard or over-type (especially as you would then effectively be pressing against a hard surface) then the jarring effect on the lower arm would not help someone with a lower arm, wrist or knuckle problem.
  3. Even if there were such a thing as keys with no resistance whatsoever such as the buttons on a microwave oven or in an optical keyboard where letters are typed by breaking a beam of light, they would probably not help a wrist condition, again because of the jarring effect.
  4. The amount of “travel” or transverse motion required to activate a key is also significant factor.  If you have aching knuckles, no matter how light the touch, having to move your fingers a lot might not be a good idea.

So our ideal “light touch” keyboard would have a low resistance or actuating pressure (or as low as possible), very little transverse motion and probably a cushioned landing. Unfortunately we are not aware of any keyboard on the market that satisfies all of these conditions.

membrane keyboard                   Scissor_switch_mechanism_svg

Dome switch mechanism           Scissor switch mechanism

Of the multiple technologies used in the manufacture of keyboards (there are more than 10), there are probably just two technologies that are used for over 99% of all computer keyboards; they all tend to be membrane based, utilising either a dome switch or a scissor switch.  Dome switch keyboards are the most common and rely on a rubber or silicon dome shaped over a small micro-switch.  This mechanism has the advantage of being relatively cheap to manufacture and the rubber dome provides a certain amount of cushioning, which is good for RSI and any lower arm disorders.

Scissor-switch keyboards tend to be common in laptops and other portable keyboards. Usually they still utilise rubber domes, but a special plastic ‘scissors’ mechanism links the keycap to a plunger that depresses the rubber dome with a much shorter travel than the typical rubber dome keyboard.  It is this smaller, shallower footprint that makes scissor-switches popular on laptops and other portable keyboards.

Well. that’s part of the story.  What if you have aching wrists or any other aches in the lower arm?  Which type of keyboard should you use?

From our research we find that customers seem to gravitate towards four different types of keyboards:

  • Accuratus 301 Light Touch keyboardac301_1
    Although this keyboard has a membrane mechanism, it has a very low profile and requires very little finger movement.  In addition the keys are well cushioned.
  • Accuratus 500 series keyboard – K82A, K82B or K82Da500-k82b_1
    With its light touch scissor mechanism, this keyboard comes in 3 versions; with no integral mouse, with an integral touchpad or with an integral trackball.  3 different styles of keyboard but all with the same “feel” to them.
  • Flexible Soft Touch Rubber Keyboardflexible_keyboard_1
    A keyboard with a very light touch and little transverse motion.  It has the additional advantage of being virtually indestructible in that it can be rolled up and put in a handbag or case, is impervious to water and is pretty tough.  On the downside some people find it a bit “squelchy to the touch.
  • Kinesis Freestyle 2kinesis_vip3_1
    A lot of studies indicate that “split keyboards” are very good for aching wrists and other problems associated with RSI wrist conditions.  With these keyboards the left hand and right hand sides are separated by a gap and the two halves can be turned slightly to form a tent shape, so that you are typing in what is called the “handshake” position.  This nearly always feels more comfortable but would only be suitable for a touch typist, not your typical “hunt and peck” typist who uses just one or two fingers.
    The Kinesis keyboard is a split keyboard and has quite a soft touch, the angle of split being dependent on which Accessory kit you buy.

So which is there such a thing a an ergonomic light touch keyboard?

It is all very subjective, and what is comfortable for one person may feel very uncomfortable for another.  In our view there is no one-type-fits-all keyboard and unfortunately there is nothing to beat trying out the keyboard that you want to buy beforehand.

One response to “Is there such a thing as an ergonomic light touch keyboard?”

  1. Thanks for the list of four keyboards.

    What are the travel distance, operation point, actuation force, and force to bottom out of each of these keyboards?

    Ideally I’d love to see a travel vs force plot.

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