Single-handed typists typically find using standard keyboards time consuming and inefficient. Subsequently, recent ergonomic developments have introduced a range of one handed keyboards that can be used by individuals with carpal tunnel syndrome, occupational overuse syndrome, cumulative trauma disorders, spasticity, hemiplegia, motor control disorders or upper limb amputees. These keyboards aim to improve independence and enable proficiency.
Typically, single handed keyboards are unique in terms of the size and shape of keys, the order of keys, the shape of the keyboard and are specific to right or left handed individuals. Generally speaking, the shape of the one handed keyboard matches natural hand movement and the key arrangement is sculpted to provide appropriate heights suited to each finger length to reduce fatigue and increase accuracy.
Features of one-handed keyboards (may vary between models):
- single handed keyboards replicating the function of a standard full sized keyboard
- use of a ‘chording’ function where letters, numbers, commands and macros are chorded in a combination function
- ergonomic dual layout developed specifically for left handed or right handed use
- individual number pads as well as a number panel alongside the letters to prevent fatigue
- ‘push on’ and ‘push off’ functions for ‘shift’, ‘control’ and ‘alt’ keys.
- re-arrangement of the letter and number keys on a standard keyboard to a more efficient position
- number keys on one side and letter keys on the other side
- use of space bar to change left half of keyboard into the letters from the right half of the keyboard.
Workplace solutions and adjustments
There are various factors to consider when selecting an appropriate single handed keyboard including:
- the individual’s capacity to learn
- their typing proficiency
- the type of work to be performed
- ease of use and portability for use at work.
Ergonomic one handed keyboards should be positioned to the left or right of the midline depending on the dominant limb in use. For example if the user is using a right handed keyboard, it should be positioned to the right of the midline.
It is recommended a keyboard is operated with the elbow flexed to 90 degrees and the wrist in a neutral position so it maintains alignment with the forearm. Wrist supports can also be considered if extra support is required.
References
Eilam, Z. 1989, Human engineering the one-handed keyboard, Applied Ergonomics, vol. 20, pp.225 – 229.
Independent Living Centres Australia Inc. 2007, Computer Access and Environmental Control – Keyboards, keypads & alternatives, Independent Living Centres Australia, Sydney, viewed 31 May 2010, http://www.ilcaustralia.org/home/search3.asp?State=NSW&MC=62&MinC=44.
HemiHelp (no date specified), Computers and ICT, HemiHelp, London, viewed 31 May 2010, http://www.hemihelp.org.uk/families/everyday_living/computers.
Maltron Keyboards 2007, Single handed keyboards, PCD Maltron LTD, Staffordshire, viewed 31 May 2010, http://www.maltron.com/maltron-advantage-single.html.
Matias, E. 1996, One handed touch typing on a QWERTY keyboard, Human-Computer Interaction, vol. 11, pp. 1-27.
Matias (no date specified), Matias Half Keyboard and 508 Keyboard, Matias, Ontario, viewed 31 May 2010, http://matias.ca/halfkeyboard/index.php.