|To use different muscles during keying.
To reduce awkward postures of the arms or hands during keying. The main target postures are deviation (sideways bending at the wrist) or pronation (working with palms facing the floor).
|Possible Drawbacks or Misuse:
||Some users find it difficult to adapt to new keyboard shapes alternatives. Error rates sometimes increase and speed slows. Most typists eventually return to their original accuracy and speed.
Often, a wrist/palm rest needs to be reshaped to fit an unusual horizontal or vertical angle of the keyboard. Inexpensive raw-foam wrist rests are a good solution because they can be cut. Many of the newer gel rests can be bent to fit a split keyboard.
Some alternative keyboards need additional arm support, because the keyboard is tented or raised higher in the center and requires higher hand positions than usual.
Some alternative keyboards are longer from side to side than the traditional rectangular keyboard. This may limit the space available for the mouse or result in an offset keyboard position relative to the center of user’s body. This can cause more reaching to the mouse or keying with the keyboard off set to the left.
|General End-User Instructions:
||Get used to alternative devices slowly. If discomfort develops, it may be due to the new design. Evaluate the situation carefully.
Some alternative keyboards are adjustable in the amount of side to side split, and central tenting. If a user has difficulty adapting they can start with very minimal adjustments and then can increase the split and tenting angles until their wrists and arms are comfortably aligned.
As with all types of keyboards, users should pull the hands back away from the keys when pausing to read, think, talk, listen or wait for new pages to load. Use the wrist/ palm rest during these micro breaks.
Curved Keys (above)
Split Keys (above)
Adjustable Angle (both split and tent)
|For keyboards there are a number of choices on the market including those with simple changes to the rows of keys, changes to the actual key order or arrangement, split and/or angled keyboards.
Other combinations and alternatives include:
- Dished out key placement
- Keyboards with a mouse-like device imbedded in the front center
- Keyboards that mount on the arm rests
- Keyboards that completely separate into two parts
- Keyers that use as few as 7 keys in combinations or “chords” to produce words, just to mention a few options
Ergo Light: Traditional rectangular layout with minor changes to the rows of keys. Keys can be arranged in a curved shape i.e. 6 degree angle, or aligned in an inverted chevron shape to align with natural finger extensions.
Fixed Split Keys: Some of the more common ergonomic keyboards have keys arranged in a split or angled pattern to encourage straight wrist and finger and arm alignment. Some of these also have a raised or tented central position of the keyboard to limit pronation – the inward twisting of the arm that turns the palm horizontal. One of these is split with a 12 degree chevron for the keys and a central peak. The 14 degrees side to side slope of the keys reduces pronation.
Adjustable Angle: Keyboards that adjust from a closed position allow users to use the board in the usual way, or to gradually adapt to new positions. Most adjustable keyboards can also adjust the degree of tenting from flat up to 30 or even 90 degree upright angle to limit pronation.
Detachable/ Optional Number Pad: Several of the Adjustable Ergonomic keyboards are available with or without a number pad. No number pad allows the mouse to be placed closer resulting in less reaching. Intensive number pad users often prefer the detachable device because they can place it for optimal comfort and performance.
Having a variety of keyboards and pointing devices available for users to test before buying often produces the best results.