A well-known problem for typists is the physical stress and strain arising from the need for the typist to adopt a relatively stationary, usually erect and rigid posture when touch-typing.  Such strain may be experienced over essentially the entire physique including, more commonly the fingers, wrists, arms, shoulders, neck and back, essentially the entire upper torso of the individual typing.  Such stress and strain accelerates fatigue, increasing errors and slowing the entire typing process.  Furthermore, actual injury may result, requiring time off work. 
This problem has increased with the adoption of personal computers where much information is input directly from the keyboard. 
Further problems arise with the inexorable trend to miniaturization resulting in powerful pocket sized processors.  Such miniaturization however, produces further difficulties of design in that the individual keys must be sufficiently spaced apart to enable operation by both hands without risk of inadvertent depression of adjacent keys.  At the same time, the use of a conventional touch typing technique should be accommodated for efficient input of information.  Students, executive, reporters and others are increasingly desirous of taking notes at lectures and other meetings by direct input on a keyboard when touch-typing is essential to maintain the necessary speed to keep pace with the proceedings. 
It is acknowledged as known to provide a keyboard designed to be operated by only one hand by substantially reducing the number of keys thereon.  However, a conventional touch typing is not therefore possible. 
U.S. Pat.  No.  Re 32,977 to Goton, issued Jul. 4, 1989 discloses a keyboard structure curved about a single transverse axis to improve to improve key accessibility.  However, no adjustment of inter-key spacing is permitted, operation by a single hand is not intended and support of the hand during typing is not taught.