Use Of Keyboard Research Articles

Computer Workplaces for Primary School Children - What about Ergonomics?

Computer related RSI before 20 years of age? This rather provocative question put focus on the increasing number of children and young people requiring treatment for muscular problems, particularly from the shoulder and arm region, problems that are related to the use of computer mouse and keyboard. The usage of computers has increased during the last years and particularly in the ages from 7 to 10. Young children are using computer in schools, in spare time activities outside schools and in the homes. The number of hours that children are using computers will most probably increase even further as many schools are prioritising investments in this area. The objectives with this study were to create a survey of computer work place design in the school environment and to evaluate this from an ergonomic and physical point of view, regarding the situation for both pupils and teachers. The study has pointed out that there is a limited ergonomic knowledge among teachers and other responsible people working in schools. This lack of awareness among the majority of teachers is affecting two different problems; firstly the physical strain children are exposed to when using computers due to bad workplace design and secondly it gives the children a lack of awareness of the importance of ergonomic aspects in workplace design. The saying “We do not train for school, we train for life” is very true, particularly in this case. To support teachers and other people in the schools, responsible for the use of and training with computers, a hand book, based on the outcome of the study, has been produced. The handbook contains headlines as Computer ergonomics in the school environment; To the teacher; To the student; Checklist and finally a short chapter: To you that only have the time to read two pages. The handbook should be distributed free of charge to all Swedish schools.

Cumulative trauma disorders and keyboarding work

This paper reviews the current state of the relationship between computer keyboard use and the development of cumulative trauma disorders [CTDs] as found in the literature. Alternative keyboard designs using biomechanical evaluation methods as justification for their use are also reviewed. Critical factors such as the repetitiveness of the keyboarding task, the tendency of users to type with excessive force and forcing users to maintain prolonged awkward and static postures are discussed in relation to CTD development. Suggestions for future research into this area and possible keyboard substitutes are also reviewed. Relevance to industry The increasing incidence of cumulative trauma disorders (CTDs) in the workplace has led to a search for possible contributing factors and ergonomic interventions. The computer keyboard input device has received much attention in the past and is believed by many to be a prime factor in the etiology of CTD occurrence. This paper reviews the scientific literature published thus far that explores the relationship between CTD development and keyboard use in the service industries.

New Research on Office Seating Issues

The four papers at this symposium describe leading-edge ergonomic research on the design of office chairs. Results from new studies on the dynamics of back motion and active sitting, the concept of spineprints, and their relevance to ergonomic seating design will de described. Work on the postural benefits of chair armrests, and their influence on wrist posture during keyboard use will be presented. The implications of these studies for rethinking the requirements for an ergonomic chair will be discussed.

Effect of four computer keyboards in computer users with upper extremity musculoskeletal disorders

Eighty computer users with musculoskeletal disorders participated in a 6-month, randomized, placebo-controlled trial evaluating the effects of four computer keyboards on clinical findings, pain severity, functional hand status, and comfort. The alternative geometry keyboards tested were: the Apple Adjustable Keyboard [kb1], Comfort Keyboard System [kb2], Microsoft Natural Keyboard [kb3], and placebo. Compared to placebo, kb3 and to a lesser extent kb1 groups demonstrated an improving trend in pain severity and hand function following 6 months of keyboard use. However, there was no corresponding consistent improvement in clinical findings in the alternative geometry keyboard groups compared to the placebo group. Overall, there was a significant correlation between improvement of pain severity and greater satisfaction with the keyboards. These results provide evidence that keyboard users may experience a reduction in hand pain after several months of use of some alternative geometry keyboards.

A model of keyboard configuration requirements

This paper presents a user model: a computer program which examines the behaviour of a real computer user. The model encompasses four aspects of keyboard use which can present difficulties for people with motor disabilities. Where relevant keyboard configuration options exist, the model chooses appropriate settings for these options. The model bases its recommendations on observation of users typing free English text. It is intended to form part of a dynamic configuration support tool. Empirical evaluation showed the model to be very accurate in identification of a given user's difficulties. Where recommended configuration options were tried by the participants, high levels of error reduction and user satisfaction were found.

Mouse versus keyboard use: A comparison of shoulder muscle load

Use of the computer mouse as an input device at visual display units is increasing, yet few studies could be found that directly addressed related musculoskeletal problems. Tasks similar to mousing, such as keyboarding, have been shown to result in static muscle loading of the shoulder, therefore the potential may also exist for increased neck and upper limb disorder with mouse use. The major aim of this pilot study was to compare the dominant shoulder muscle load from upper trapezius and anterior deltoid, gross postures and discomfort during mousing and keyboarding. This was performed in an effort to investigate whether use of the computer mouse is likely to be a risk factor for neck and upper limb disorders and the extent of this risk compared to keyboarding. Eight subjects performed a 10 min computer task with both mouse and keyboard input. Electromyographs of anterior deltoid and upper trapezius muscles, observations of posture and ratings of discomfort were collected. Group differences suggested increased anterior deltoid loads with mouse use and decreased trapezius loads. Also evident was the considerable inter-individual variation in muscle loads. This may help explain the pattern of work-related neck and upper limb disorders. Relevance to industry Investigation of shoulder muscle loading during mousing may help identify risk factors contributing to the development of potentially associated neck and upper limb disorders. Costly negative effects of these disorders to industry can include workers compensation claims, decreased productivity and reduced user satisfaction and well being. Once possible risk factors such as shoulder load are identified, approaches to their minimisation in industry may then be addressed.

Occupational factors and unexplained physical symptoms

Liaison psychiatrists are frequently asked to see people with chronic, debilitating and unexplained physical symptoms, in particular chronic pain and chronic fatigue. People with these conditions have often seen many doctors and received multiple medical investigations, but rarely have had any effective treatment or even explanation for their symptoms. There are many reasons for focusing on occupational factors in this patient group. First, many people may attribute their symptoms to workplace exposures. For example, back pain may commonly be put down to accidents; upper limb disorders to use of keyboards or repetitive manual tasks; and headaches and fatigue to visual display units or air conditioning. These attributions have prognostic and legal implications, and are likely to affect the course of treatment. Second, for those who have had prolonged sickness absence, it is often necessary to make decisions regarding return to work or to help them negotiate the often lengthy and complex medical retirement process. This may be a major stumbling block in managing such people. Finally, psychiatrists are frequently invited to write medico-legal reports regarding the role of occupational factors in causing unexplained physical symptoms. This article aims to address these issues and provide some practical guidance to clinicians.

Manual dexterity and keyboard use in spastic hemiparesis: a comparison between the impaired hand and the ‘good’ hand on a number of performance measures

Manual dexterity and keyboard use in spastic hemiparesis: a comparison between the impaired hand and the ‘good’ hand on a number of performance measures

Computer mouse or Trackpoint—effects on muscular load and operator experience

The aim of the study was to evaluate four different modes of human-computer interaction. The modes were: use of the keyboard alone as input device, use of keyboard and mouse, use of keyboard and mouse with a three-dimensional arm support, and use of a keyboard with a Trackpoint device in its centre. Ten women and 10 men volunteered to participate. Questions asked were whether working in the different modes influenced shoulder and forearm muscular load differently during word processing, and how much strain on the neck, shoulder and arms subjects perceived in the different modes. Muscular load was studied with electromyography in three shoulder muscles and three forearm muscles. The subjects also rated the different modes in one questionnaire concerning perceived strain and in one concerning preference for any of the modes tested. Intra-individual analysis for each muscle and mode showed two possible ways of decreasing the strain from computer mouse work on the shoulder muscles—either to use Trackpoint or to use the mouse combined with the movable arm support. However, both of these computer-interaction modes increased the muscular load in the hand and forearm.

Risk factors for carpal tunnel syndrome in a general population.

OBJECTIVE: To determine the individual, physical, and psychosocial risk factors for carpal tunnel syndrome in a general population. METHODS: Population based case-control study in Marshfield epidemiological study area in Wisconsin,...

Overuse syndromes of the upper limb and the upper limb tension test: a comparison between patients, asymptomatic keyboard workers and asymptomatic non-keyboard workers

SUMMARY. Overuse syndromes of the upper limb (OSUL), also known as repetitive strain injury (RSI) remains a contentious issue that affects a large number of keyboard workers. This research used the results of a modified upper limb tension test (ULTT) performed on three independent groups to look for any similarities or discrepancies between them. The subjects were all female aged between 25–40 years, with groups consisting of 12 OSUL patients, 20 asymptomatic keyboard users and 19 asymptomatic non-keyboard users. The ULTT was positive in 100% of the patient group supporting several hypotheses that state that the pathology of OSUL is neurogenic in origin. The results of the two asymptomatic control groups were predicted to be the same, however this was not found to be the case. Unrelated t-tests were used to analyse the data showing that the keyboard users had a significantly positive ULTT compared to non-keyboard users, which were viewed as a normal control group. This suggests that a subclinical pathological state exists in the keyboard user group. Various subclinical physiological changes caused by prolonged sitting and keyboard use are suggested as possible causes for these results. This research highlights the need for intervention in an office environment to prevent further cases of OSUL from developing.

Evidence for Work-Related Musculoskeletal Disorders

Evidence for Work-Related Musculoskeletal Disorders

Changes in wrist postures during a prolonged typing task

Twenty experienced typists participated in a laboratory based study to determine whether wrist and forearm postures changed over a 4 hour period of intensive keyboard use. Subjects were randomly assigned to use a conventional keyboard or a fixed split keyboard. Posture data was acquired using electrogoniometers after a 10 warm-up period and at the end of each hour. Wrist and forearm postures did not change significantly over the four hour period among subjects using the split geometry keyboard. On the conventional keyboard, all joint postures were stable except right wrist extension and left forearm pronation. The right wrist extension increased by 5° over the four hour period (p=.002) and left pronation decreased by approximately 9° (p=.001). Wrist postures among typists exposed for the first time to a split keyboard remained constant throughout a four hour period of intensive typing. On the conventional keyboard, some postures drifted over the four hour period.

Methodological limitations in the study of video display terminal use and upper extremity musculoskeletal disorders

Upper extremity musculoskeletal disorders may occur as a result of work with keyboard-equipped video display terminals. Many studies of the associations between keyboard use and upper extremity disorders have appeared in both the human factors and occupational epidemiologic literature. Methodological limitations and inconsistent results have limited conclusions that can be made from these studies, however. Although exposure conditions can be carefully controlled, human factors studies are limited by relatively small sample sizes, short exposure durations, and reliance on outcome measures with unknown relevance to chronic adverse health effects. Epidemiologic studies have been limited by poor ascertainment of both exposure and health outcome. Many have failed to control for any potential confounding. An almost exclusive reliance on cross-sectional study designs has resulted in possible bias from selective survival, exposure-effect reversal, and poor estimates of exposures occurring prior to development of the disorder. Given the inconsistency in the literature and the growing controversy surrounding this issue, prospective study of this question using objective methods for assessment of exposure and health outcome is recommended. This design allows identification of incident cases and minimizes bias from selective survival. In addition, ergonomic and psychosocial variables prior to onset of symptoms can be ascertained periodically. Given estimates for up to 100 million video display terminals to be in use in the United States by the year 2000, clarification of the health effects of their use is critical. © 1996 Wiley-Liss, Inc.

Methodological limitations in the study of video display terminal use and upper extremity musculoskeletal disorders.

Upper extremity musculoskeletal disorders may occur as a result of work with keyboard-equipped video display terminals. Many studies of the associations between keyboard use and upper extremity disorders have appeared in both the human factors and occupational epidemiologic literature. Methodological limitations and inconsistent results have limited conclusions that can be made from these studies, however. Although exposure conditions can be carefully controlled, human factors studies are limited by relatively small sample sizes, short exposure durations, and reliance on outcome measures with unknown relevance to chronic adverse health effects. Epidemiologic studies have been limited by poor ascertainment of both exposure and health outcome. Many have failed to control for any potential confounding. An almost exclusive reliance on cross-sectional study designs has resulted in possible bias from selective survival, exposure-effect reversal, and poor estimates of exposures occurring prior to development of the disorder. Given the inconsistency in the literature and the growing controversy surrounding this issue, prospective study of this question using objective methods for assessment of exposure and health outcome is recommended. This design allows identification of incident cases and minimizes bias from selective survival. In addition, ergonomic and psychosocial variables prior to onset of symptoms can be ascertained periodically. Given estimates for up to 100 million video display terminals to be in use in the United States by the year 2000, clarification of the health effects of their use is critical.

A computer utility for automated retrieval of radiology reports.

Many radiology information systems (RISs) installed during the 1980s have a user interface that is crude by today's standards. We explored improving this user interface by using the local processing power of the personal computer. In this article we describe a computer program that significantly enhances the ease of report retrieval by automating much of the interaction with our RIS, which is IDXrad. The program, named DERVISH, runs under DOS on International Business Machines-compatible personal computers having an 80286 or faster processor, an enhanced graphics adapter or video gate array display, two serial ports, a mouse, and a bar code wand. It is written in the C++ programming language. Input may be keyboard, mouse, or bar code wand, and reports may be displayed singly or multiply and printed to a local printer or an RIS printer or copied to a disk file. DERVISH not only performs many of the routine tasks of an RIS session such a logging on and off but also provides a menu-driven environment for report display, including optional restriction of the report list to related prior reports. Keyboard use is minimized in favor of a mouse and a bar code wand. DERVISH emulates a standard RIS terminal for functions other than report retrieval. Originally intended to help retrieve the prior radiology reports of a patient at hand, DERVISH has found use in our quality management effort as well, simplifying comparison of reports from related radiologic techniques. An early version suffered poor acceptance because of its nonstandard interface and frequent malfunctions. The current version is presently in use in our emergency radiology department. DERVISH serves not only as a useful utility in itself but also as a demonstration of the ability of the local processing power of a desktop computer to improve the user interface of an aging RIS and to extend its functional life.

Paired Keyboards as a Tool for Internet Exploration of Third Grade Students

This study focuses on the use of paired keyboards attached to a single microcomputer as a means to facilitate internet exploration. A classroom teacher with nineteen years experience and an educator worked with an intact third grade class of twenty-nine public school students. Children worked in pairs, with one child considered as the knowledgeable other who, through interaction with a partner, might extend the partner's Zone of Proximal Development. This type of learning environment allowed for selective intervention among groups which facilitated and accelerated internet exploration and made the experience a much more successful and rewarding one. Interviews along with ongoing weekly observations were employed to examine this scaffolding approach while the students were on-line. The use of paired keyboards become, in a Vygotskian sense, a tool in children's learning. Review of the process indicated that this approach enabled students who were unfamiliar with either computers or the internet to be successful in their quest for information and global collaboration. The implication is that meaningful learning takes place when educators are creative in the way that computer hardware/software is used in support of facilitating education through internet exploration.

Visual Display Terminal work — A perspective on long-term changes and discomforts

A study was undertaken to investigate whether work with Visual Display Terminals (VDTs) and perceived changes in work or work equipment among VDT workers were associated with increased risks of certain discomforts. The study group consisted of respondents to questionnaires in both 1981 and 1987 among 353 office workers. Eye discomforts and probably also hand/wrist problems were in general associated with VDT work. Among the VDT workers, the risk of eye discomforts increased among those who reported increased immobility and use of keyboards. Increased keyboard use also increased the risk of hand/wrist problems. On the other hand, it appeared that new keyboards alleviated the problems in some individuals as to neck, shoulder and upper arm problems. The installment of new lighting systems was tentatively associated with increased risk of skin problems in some companies, whereas the purchase of new office furniture was associated with increased risk of neck and shoulder problems among men. Increased immobilisation and monotony during VDT work were associated with increased risk of eye discomforts, skin problems and hand/wrist problems.

Measurement of creep strain of flexor tendons during low-force high-frequency activities such as computer keyboard use

The aim of this study was to measure tendon strain during low-force, high-frequency activities such as computer keyboard use. Prior to creep strain testing an estimate of flexor tendon force during keyboard use was made. Tendon force was measured indirectly by comparing electromyographic activity of the flexor and extensor digitorum muscles in five human volunteers for various hand activities. Results of the electromyographic study showed that flexor tendon forces during keyboard use may be as high as 60 N. Sixty eight flexor digitorum tendons from 17 fresh-frozen cadaver hands were used for the creep strain tests. Three loading conditions (static, 1 Hz cyclic, 1 4 Hz cyclic) and four load levels (10, 20, 50, 100 N) were used. Results of the creep study showed that for a flexor tendon force of 60 N the total strain of the tendon would be approximately 1.8%. This does not appear to be enough strain to cause permanent damage to the tendon according to current cumulative strain models.

A comparison of three computer cursor control devices: pen on horizontal tablet, mouse and keyboard

It might seem likely that an electronic pen manipulated on a desk top tablet would elicit better performance and greater user preference than other cursor control devices. This paper presents four experiments that examine this hypothesis by comparing speed, accuracy, and preference for a pen device with the two most widely used cursor control devices (mouse and keyboard) in a drawing (graphics) environment. In the context of these experiments pen use was never significantly faster than mouse, while both pen and mouse use were always significantly faster than the keyboard. In contrast, keyboard use was always more error free than the mouse, which in turn was always more error free than the pen. These error differences were significant in a majority of the cases. Subjects expressed preference for the mouse in general work (significant). For highly accurate work, subject preference was for the keyboard (significant).