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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.apergo.2006.05.001 Byline: David Rempel (a)(b), Alan Barr (a), David Brafman (a), Ed Young (a) Keywords: Keyboard; Design; Posture Abstract: There is increasing evidence that alternative geometry keyboards may prevent or reduce arm pain or disorders, and presumably the mechanism is by reducing awkward arm postures. However, the effect of alternative keyboards, especially the new designs, on wrist and arm postures are not well known. In this laboratory study, the wrist and forearm postures of 100 subjects were measured with a motion analysis system while they typed on 6 different keyboard configurations. There were significant differences in wrist extension, ulnar deviation, and forearm pronation between keyboards. When considering all 6 wrists and forearm postures together, the keyboard with an opening angle of 12[degrees], a gable angle of 14[degrees], and a slope of 0[degrees] appears to provide the most neutral posture among the keyboards tested. Subjects most preferred this keyboard or a similar keyboard with a gable angle of 8[degrees] and they least preferred the keyboard on a conventional laptop computer. These findings may assist in recommendations regarding the selection of keyboards for computer usage. Author Affiliation: (a) Ergonomics Program, Department of Medicine, University of California, San Francisco, CA 94804, USA (b) Department of Bioengineering, University of California, Berkeley, USA Article History: Received 31 January 2006; Accepted 5 May 2006

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.apergo.2005.09.005 Byline: Gerard P. van Galen, Hanneke Liesker, Ab de Haan Keywords: Keyboard design; Repetitive strain injury; Muscle tension Abstract: To circumvent the awkward pronated hand position inherent to conventional horizontal keyboards, a vertical, split keyboard was designed with flexible cushions supporting the wrists, allowing relaxed hand and arm postures. During eight twice-weekly 30-min training sessions, the performance and subjective comfort of nine experienced typists were tested. Typing speed and error percentage, and surface electromyographic activity of six forearm muscles and two postural muscles were recorded in separate sessions at the end of each week. Typing speed rapidly recovered to the preset rate of 300 keystrokes/min and error percentages were similar for the two keyboards. The vertical keyboard caused lower muscular activity in especially finger extensor muscles, did not increase postural muscle activity, and self-reported comfort was higher. Thus, the vertical keyboard was easily mastered, was experienced as comfortable, and caused less stress on muscles sensitive to repetitive strain injuries. Author Affiliation: Radboud University Nijmegen, P.O. Box 9104, NL 6500 HE Nijmegen, The Netherlands Article History: Received 4 November 2004; Accepted 27 September 2005

A comparison and analysis of rubber-dome desktops, spring-column desktop and notebook keyboards in terms of key stiffness and fingertip typing force was conducted. The results could help in optimizing computer key design so that subject discomfort and fatigue are reduced.

INTRODUCTION For more than 20 years there has been concern that working at computer terminals could lead to musculoskeletal discomfort and disorders (Bammer & Martin, 1988; Bergqvist, Wolgast, Nilsson, & […], The purpose of this study was to examine differences in experienced typists' performance, posture, and musculoskeletal pain when using a split, adjustable (SA) computer keyboard and when using a standard flat keyboard. In addition, the use of a wrist rest was examined for performance, posture, and musculoskeletal pain effects. Eighteen participants were exposed to the SA keyboard and a flat keyboard in a laboratory study of text typing for four consecutive hours on five days. The results indicated that after just 2 h of orientation and practice, the participants could perform as well on the SA keyboard as on the flat keyboard. The SA keyboard provided advantages for reduced wrist/hand pronation. There was no difference between the keyboards in the level of musculoskeletal pain reported by participants after typing. However, they reported increased pain in the back, neck, shoulders, and wrists from the beginning to the end of each of the experimental periods for both keyboards.

Concerns have arisen that the keyboard is a causal factor in the development of work-related musculoskeletal disorders (WRMDs) among video display terminal (VDT) operators. A number of alternative keyboard designs have been developed with altered geometry in an effort to improve comfort in keyboard operation. However, few data are available to substantiate whether these new keyboard designs are actually effective in reducing discomfort and musculoskeletal problems in users. The purpose of this study was to provide data on the efficacy of certain alternative keyboard design features (e.g. splitting the keyboard in half, and laterally inclining the keyboard halves) in reducing fatigue and musculoskeletal discomfort among keyboard operators. The study also explored the effects of these design features on performance. Fifty subjects performed a text-entry task for one day on a standard keyboard, then were assigned to one of five keyboard conditions for an evaluation period of two days (i.e. 10 subjects/condition). Outcome measures included performance (i.e. keystrokes/h, errors/h) and self-report measures of discomfort and fatigue. The results indicated an initial decline in productivity when subjects began typing on two of the alternative keyboards, but these productivity losses were recovered within the two-day evaluation period. The results also indicated no significant differences between keyboard conditions in discomfort and fatigue. These results suggest a minimal impact of the keyboard design features examined in this study on productivity, comfort and fatigue, at least after two days of exposure. Keywords: alternative keyboard design, keyboard evaluation, work-related musculoskeletal disorders

Evaluation of a split keyboard adjustable in four separate ways revealed that a system developed to test alternative keyboard designs correctly and consistently gauges wrist angle and fingertip force. The system consisted of measurements of wrist position with electronic and manual goniometers, strain gauges in some keys to measure fingertip force on the keyboard, a questionnaire to determine subjects' level of comfort and assessment of ease of use of the keyboard and a computer program to record productivity. The best keyboard design will involve the ideal combination of all four factors.

This paper shows that the Chord Principle, used to couple chords one-to-one with phonemes, can be applied to the design of a new and powerful keyboard for the stenograph. The new keyboard is called the Minimum Chord Stenograph, MCS (pronounced My Cass). The training time is quite short. Within the limits imposed by no more than 50 hours' training, MCS' input data rates are superior to those from the old stenograph. One can definitely state that MCS requires a modest time to learn the code and, in return, gives a means for rapid entry of phoneme-based speech. In order to justify design considerations and in order to provide a base against which to compare MCS' performance, a review is given of relevant features of the standard typewriter (QWERTY), Chord Keyboards, and the normal Stenograph. Detailed insight into the operator-and-machine as a unit is provided by interval measurements [t.sub.p] (r) taken directly from tests when MCS is being operated. [t.sub.p] (r) is the time measured from the end of one chord and the end of the next chord r. A pseudochannel capacity [C.sup.p] (r) is used to show that MCS' performance gets better as training time is increased. Although QWERTY works with alphabet letters as input and MCS works with phonemes as input an attempt is made to compare QWERTY and MCS in terms of 'words per minute.' The two methods are not very different in time to acquire a first competence, but MCS's top speed after 50 hours of training is a little better than QWERTY's speed for operators all of whom had at least a year of training and usage.

A new approach to designing input device keys is proposed, and a TV remote controller is used as an example to demonstrate the new approach for studying the relationship between fingerprints and key geometry. One hundred subjects' fingerprints of thumbs and index fingers of both hands were collected, and a computer program was used for converting the fingerprint to a bitmap form. Subsequently, the data were analysed to provide some guidelines for determining the key size and key shape for the input device. Finally, the fingerprints were used to study the pattern of finger press and the justification for keycap curvature for finger placement. The results showed that the new approach can be useful in guiding designers of input device keys. A further benefit of this study is in providing a more systematic approach with considerable general potential for studying input device keys.

Electronic locks, for which a password is entered on a computer-style keyboard, are described. Certain security problems associated with them are analysed. It is proposed that different labelling of the keyboard keys can reduce this problem. Theoretical figures are provided to support this claim and to aid design.

Consider the problem of assigning more than one symbol of a finite alphabet A to the same key on a keyboard. Since multiple symbols of the alphabet A reside on the same key, the representations of all the words in a finite dictionary H need not be unique. The problem we study is one of optimally assigning the symbols of the alphabet to the keys of a given keyboard with a view to minimize the total number of words that have ambiguous representation. The problem, as stated previously, is proven to be NP-hard. After presenting the only reported solution to the problem, we report a fast learning automation-based solution to this problem. Experimental results demonstrating the power of this solution have also been presented.

Replacing a keyboard can be stressful for operators who take calls all day, particularly when special functions must be sacrificed. This study applied several participatory design techniques to involve over 3000 operators in the redistribution of function keys on their replacement keyboard. Video analysis and manual data logging methods were surprisingly accurate when measured against software logs. User acceptance was excellent. In the initial cutover program, operator performance levels returned to normal very quickly, resulting in over-confidence and unrealistic expectations of post-implementation performance for the remaining call centres because the focus was on the technology rather than on the impact of technology on business benefits. As a consequence, business plan requirements for future projects have now been changed to accommodate predictions of post-implementation performance and taking into account other changes happening at the same time. [C] 2001 Elsevier Science Ltd. All rights reserved. Keywords: Keyboard design; Participatory design; Iterative processes

University of Florida graduate Peter McAlindon says he has taken the stress out of using computer keyboards. With the National Science Foundation's (NSF) Small Business Innovation Research (SBIR) program, McAlindon [...]

Anil writes 'Thanks to Rex Gooch for adding some more considerations and information to my keyboard revision musings in May. I would like to know more about the AZERTY keyboard, [...]