Expanded keyboards are ergonomically designed keyboards to assist people with poor motor control and prevent the development of disabling conditions associated with typing for long periods of time. They are also known to correct the computer users sitting posture whilst typing. Typically, expanded keyboards are designed to straighten the wrists by placing them into a neutral position, minimise awkward postures, reduce unnecessary repetition and avoid excessive force.
Many of the expanded keyboards are engineered with a contoured shape using curves to replace the symmetry of a standard keyboard. This asymmetrical design keeps elbows and wrists in a constantly changing position to reduce repetitive stress injuries.
Expanded keyboards are often used for individuals with autism or other intellectual disabilities as a standard keyboard with mixed letter and function keys can often be too overwhelming. Studies have shown a specially designed keyboard, known as an expanded membrane keyboard, meets the needs of individuals with impairments in learning ability and concentration. An expanded keyboard can be designed larger in size with letters placed in a logical order rather than the standard QWERTY key arrangement.
Workplace solutions and adjustments
There are various types of expanded keyboard that may be beneficial in the workplace for people with disability, including:
- Ergonomic keyboard—a standard keyboard is split into three independently moving sections attached to a track. These three sections can be ordered to suit the individual needs of the user, and adjusted to variable angles of 20, 30 and 45 degrees in all four directions
- Split keyboard— designed to straighten both wrists by rotating the left and right sides of the keyboard vertically so that the wrist is placed into a neutral vertical position
- Tented keyboard—typically tilts the left and right sides of the keyboard up like a tent. It places the wrists in a less neutral position than the split keyboard, whilst still being effective in preventing prolonged pronation (palms facing down) and ulnar deviation (wrist angled towards the little finger)
- Goldtouch keyboard—an adjustable segmented keyboard designed to allow the computer user to adjust the keyboard horizontally and vertically to achieve the most ergonomic and comfortable position. It has been proven to be effective in reducing muscle load and reducing the risk of repetitive stress injuries such as carpal tunnel syndrome, deQuervains syndrome, thoracic outlet syndrome, tendonitis and tenosynovitis
- Overlays—unlike a standard keyboard, this uses a programmable surface with specifically designed overlays to enable users a more simple access tool for computing.
References
Independent Living Centres Australia Inc. 2007, Computer Access & Environmental Control, Independent Living Centres Australia Inc., Sydney, viewed 31 May 2010, http://www.ilcaustralia.org/search2.asp?State=WA&MC=62.
National Institute for Occupational Health and Safety (NIOHS) 2007, Alternative Keyboards, US Department of Health and Human Services, Atlanta, viewed 31 May 2010, http://www.cdc.gov/niosh/pdfs/97-148.pdf.
National Centre to Improve Practice (NCIP) 1998, Using an expanded keyboard to help students with autism to learn to write, Education Development Centre U.S. Department of Education, Massachusetts, viewed 31 May 2010, http://secure.edc.org/ncip/LIBRARY/ec/Vignette.htm.
Option Keys 2007, Adaptive technologies for people with a physical disability, Centre for Learning Innovation - NSW Department of Education and Training, Sydney, viewed 31 May 2010, http://www.cli.nsw.edu.au/optionkeys/students/solutions_2.htm#link1.
Spectronics 2010, Intellikeys, Spectronics Australia, Rochedale, viewed 31 May 2010, http://www.spectronicsinoz.com/catalogue/intellikeys.