Use Of Keyboard Research Articles

Effects of forearm and palm supports on the upper extremity during computer mouse use

The use of forearm and palm supports has been associated with lower neck and shoulder muscle activity as well as reduced musculoskeletal discomfort during keyboard use, however, few studies have investigated their effect during computer mouse use. Eight men and eight women completed several computer mousing tasks in six arm support conditions: Forearm Support, Flat Palm Support, Raised Palm Support, Forearm + Flat Palm Support, Forearm + Raised Palm Support, and No Support. Concurrently, an infrared three-dimensional motion analysis system measured postures, six-degree-of-freedom force-torque sensors measured applied forces & torques, and surface electromyography measured muscle activity. The use of forearm support compared to the no support condition was significantly associated with less shoulder muscle activity & torque, and the raised palm support was associated with less wrist extension. Forearm supports reduced shoulder flexion torque by 90% compared to no support. The use of either support also resulted in lower applied forces to the mouse pad. Participants reported less musculoskeletal discomfort when using a support. These results provide recommendations for office workstation setup and inform ergonomists of effective ways to reduce musculoskeletal exposures.

The Effects of Virtual Keyboard Key Sizes on Typing Productivity and Physical Exposures

With mobile devices including tablet PCs, gravitating towards smaller sizes, the keyboard key sizes on these devices often have to be smaller than recommended key sizes and spacing (18 to 20 mm) for notebook and desktop keyboards. Currently, there is limited research into how key sizes can affect typing proficiency and physical exposures during virtual keyboard use. Therefore, the present study investigated how different virtual keyboard key sizes affected muscle activity, wrist posture, and typing productivity. A total of 21 subjects (12 males and 9 females) participated in a repeated-measures laboratory experiment where typing speed, accuracy, muscle activity, wrist posture, and subjective discomfort were compared between four different virtual keyboards with key sizes (width x height) of 13x13, 16x16, 19x19, and 22x22 mm with a 2-mm gutter surrounding each key. The results showed that the keyboard with the 13x13 mm keys (15 mm center-to-center key spacing) had a 15% slower typing speed (p < 0.0001), higher static (10th %tile) shoulder muscle activity (2% MVC, p = 0.01), and greater wrist extension in both hands (2° - 3°, p’s < 0.01). The study findings indicate that 13x13 mm key size may not be optimal for touch typing on a virtual keyboard.

Electromyography & Portable Computing Devices

Portable computing devices have become more lightweight and mobile due to changes in the hardware of the devices. In many cases, hardware keyboards are being replacing virtual keyboards, raising concerns on changing ergonomic exposures as, for example, muscle activation patterns may vary with virtual keyboard use. The objective was to identify active forearm muscles across select computing devices. Twenty participants completed a single test session in which seven forearm muscles were evaluated using surface EMG whilst they typed on two portable computing devices (netbook and slate computer) for 5 minutes apiece. Mean normalized EMG was analyzed and indicated that slate computers resulted in significantly lower muscle activation levels than netbooks. The extensor carpi radialis, extensor carpi ulnaris, extensor digitorum communis had the highest muscle activation levels for both the slate and netbook computers. This indicates that the same muscles should be studied for both slate and netbook computers.

334 Differences in risk factors for neurophysiologically confirmed carpal tunnel syndrome and illness with similar symptoms but normal median nerve function

ObjectivesTo explore whether neurophysiologically confirmed carpal tunnel syndrome (CTS) has different risk factors from sensory symptoms in the hand that occur in the absence of impaired median nerve conduction.MethodsWe compared...

Differences in risk factors for neurophysiologically confirmed carpal tunnel syndrome and illness with similar symptoms but normal median nerve function: a case-control study.

BackgroundTo explore whether risk factors for neurophysiologically confirmed carpal tunnel syndrome (CTS) differ from those for sensory symptoms with normal median nerve conduction, and to test the validity and practical utility of a proposed definition for impaired median nerve conduction, we carried out a case–control study of patients referred for investigation of suspected CTS.MethodsWe compared 475 patients with neurophysiological abnormality (NP+ve) according to the definition, 409 patients investigated for CTS but classed as negative on neurophysiological testing (NP-ve), and 799 controls. Exposures to risk factors were ascertained by self-administered questionnaire. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression.ResultsNP+ve disease was associated with obesity, use of vibratory tools, repetitive movement of the wrist or fingers, poor mental health and workplace psychosocial stressors. NP-ve illness was also related to poor mental health and occupational psychosocial stressors, but differed from NP+ve disease in showing associations also with prolonged use of computer keyboards and tendency to somatise, and no relation to obesity. In direct comparison of NP+ve and NP-ve patients (the latter being taken as the reference category), the most notable differences were for obesity (OR 2.7, 95 % CI 1.9-3.9), somatising tendency (OR 0.6, 95% CI 0.4-0.9), diabetes (OR 1.6, 95% CI 0.9-3.1) and work with vibratory tools (OR 1.4, 95% CI 0.9-2.2).ConclusionsWhen viewed in the context of earlier research, our findings suggest that obesity, diabetes, use of hand-held vibratory tools, and repeated forceful movements of the wrist and hand are causes of impaired median nerve function. In addition, sensory symptoms in the hand, whether from identifiable pathology or non-specific in origin, may be rendered more prominent and distressing by hand activity, low mood, tendency to somatise, and psychosocial stressors at work. These differences in associations with risk factors support the validity of our definition of impaired median nerve conduction.

VISION-BASED APPLICATION-ADAPTIVE HAND GESTURE RECOGNITION SYSTEM

With the increasing role of computing devices, facilitating natural human computer interaction (HCI) will have a positive impact on their usage and acceptance as a whole. For long time, research on HCI has been restricted to techniques based on the use of keyboard, mouse, etc. Recently, this paradigm has changed. Techniques such as vision, sound, speech recognition allow for much richer form of interaction between the user and machine. The emphasis is to provide a natural form of interface for interaction. Gestures are one of the natural forms of interaction between humans. As gesture commands are found to be natural for humans, the development of gesture control systems for controlling devices have become a popular research topic in recent years. Researchers have proposed different gesture recognition systems which act as an interface for controlling the applications. One of the drawbacks of present gesture recognition systems is application dependence which makes it difficult to transfer one gesture control interface into different applications. This paper focuses on designing a vision-based hand gesture recognition system which is adaptive to different applications thus making the gesture recognition systems to be application adaptive. The designed system comprises different processing steps like detection, segmentation, tracking, recognition, etc. For making the system as application-adaptive, different quantitative and qualitative parameters have been taken into consideration. The quantitative parameters include gesture recognition rate, features extracted and root mean square error of the system while the qualitative parameters include intuitiveness, accuracy, stress/comfort, computational efficiency, user's tolerance, and real-time performance related to the proposed system. These parameters have a vital impact on the performance of the proposed application adaptive hand gesture recognition system.

Predictors of Incident and Persistent Neck/Shoulder Pain in Iranian Workers: A Cohort Study

BackgroundPain in the neck and shoulder has been linked with various psychosocial risk factors, as well as with occupational physical activities. However, most studies to date have been cross-sectional, making it difficult to exclude reverse causation. Moreover, they have been carried out largely in northern Europe, and the relationship to psychosocial factors might be different in other cultural environments.MethodsTo explore causes of neck/shoulder pain, we carried out a longitudinal study in Iranian nurses and office workers. Participants (n = 383) completed a baseline questionnaire about neck/shoulder pain in the past month and possible risk factors, and were again asked about pain 12 months later. Associations with pain at follow-up were explored by Poisson regression and summarised by prevalence rate ratios (PRRs).ResultsAfter adjustment for other risk factors, new pain at follow-up was more frequent in office workers than nurses (PRR 1.9, 95%CI 1.3–2.8), among those with worst mental health (PRR 1.8, 95%CI 1.0–3.0), in those who reported incentives from piecework or bonuses (PRR1.4, 95%CI 1.0–2.0), and in those reporting job dissatisfaction (PRR 1.5, 95%CI 1.0–2.1). The strongest predictor of pain persistence was somatising tendency.ConclusionsOur findings are consistent with a hazard of neck/shoulder pain from prolonged use of computer keyboards, although it is possible that the association is modified by health beliefs and expectations. They also indicate that the association of low mood with neck/shoulder pain extends to non-European populations, and is not entirely attributable to reverse causation. Psychosocial aspects of work appeared to have relatively weak impact.

Combined effects of Stretching and Ergonomic Advice in Computer Professionals on the Incidence of Upper Limb Disorders

Introduction: Work-related upper limb disorders (WRULDs) continue to be problematic as the use of keyboard and mouse based work dominates the 21st century workforce. Musculoskeletal complaints in the neck and upper extremity amongst computer professionals are showing an increasing trend. Changes in work practice have led to the growing problem of work related upper limb disorders. Purpose of study: Previous studies have shown the effects of ergonomics and stretching separately on these work related upper limb disorders but none of the study so far has evaluated the combined effects of stretching and ergonomic interventions. Materials and method: 90 subjects performing computer work for at least 20 hours per week with minimum four hours continuously per day from last two years were randomly divided into three groups. In group A, subjects received hydrocollator pack, advice on ergonomics and work style modifications. In group B, subjects received same intervention as in group A with additional stretching of upper fibres of trapezius muscle and levator scapulae muscle. And group C was control group and was provided only hot packs. Pre-test and Post-test values were collected by using standard goniometer as an outcome measure. Results: After analyzing the results, significant improvement was found in all the three groups but both statistically and clinically, maximum improvement was found in group B. Conclusion: It is recommended that patients with chronic neck disability associated with occupation will be given combination of stretching and ergonomic interventions along with other conservative treatments.

Efficient Voice Integrated Browser Using Naïve Approach

The World Wide Web contains huge information from all over world. It has information about simple things as well as very complex things. This makes it very useful for everyone. Nevertheless this enormous useful information is always accessible through browser which requires use of mouse and keyboard. Hence, it does always remain unreachable to specific community of people, especially to the people with visual impairment. The concept of voice browser is not new, however in this paper we have used nai ve approach to make this efficient Voice Integrated Browser (VIB). All existing voice browsers need VoiceXML page. The conversion of existing web pages to VoiceXML pages is very tedious task and it requires extra effort. In this paper we have explained that how VIB doesn't need VoiceXML pages. We elucidate this nai ve approach and challenges faced while evolving it and eventually discussed about the future work. 

An ergonomics training program for student notebook computer users: Preliminary outcomes of a six-year cohort study

The Maine Learning Technology Initiative (MLTI) is a program established in the state of Maine in the United States of America, where all students in 7th and 8th grades are provided with a notebook computer to use at school and at home during the academic year. This study aimed to describe the anthropometric measurements and typing proficiency of a cohort of students in the MLTI. It also investigated the impact of participatory ergonomics education and use of peripheral notebook accessories on their reported musculoskeletal and visual discomfort over the first three years of a six year study. This longitudinal study commenced in 2009 with 34 students in 7th grade consenting to participate for six years through the 12th grade. Students received ergonomics education about healthy notebook use, reinforced with web-based resources; and were provided with peripheral notebook accessories including a notebook riser, and external keyboard (split or non-split) and mouse. The use of an external keyboard resulted in a reduction in neck and shoulder pain. Participants self-reported fewer headaches when using an external mouse. Using no external accessories was associated with self-reported back pain. Although other musculoskeletal discomforts decreased over time, the changes were not statistically significant. There was a trend for the reduction of visual symptoms including dry/watery eyes and sore, tired eyes during the study. Participatory ergonomics training and use of external devices may have significant health benefits for children involved in notebook programs who have daily exposure to this technology for school and leisure purposes. Internal and external validity of the results were limited by small sample size.

Speech-Based Human and Service Robot Interaction: An Application for Mexican Dysarthric People

Dysarthria is a motor speech disorder due to weakness or poor coordination of the speech muscles. This condition can be caused by a stroke, traumatic brain injury, or by a degenerative neurological disease. Commonly, people with this disorder also have muscular dystrophy, which restricts their use of switches or keyboards for communication or control of assistive devices (i.e., an electric wheelchair or a service robot). In this case, speech recognition is an attractive alternative for interaction and control of service robots, despite the difficulty of achieving robust recognition performance. In this paper we present a speech recognition system for human and service robot interaction for Mexican Spanish dysarthric speakers. The core of the system consisted of a Speaker Adaptive (SA) recognition system trained with normal-speech. Features such as on-line control of the language model perplexity and the adding of vocabulary, contribute to high recognition performance. Others, such as assessment and text-to-speech (TTS) synthesis, contribute to a more complete interaction with a service robot. Live tests were performed with two mild dysarthric speakers, achieving recognition accuracies of 90–95% for spontaneous speech and 95–100% of accomplished simulated service robot tasks.

Hand-gesture-based sterile interface for the operating room using contextual cues for the navigation of radiological images

This paper presents a method to improve the navigation and manipulation of radiological images through a sterile hand gesture recognition interface based on attentional contextual cues. Computer vision algorithms were developed to extract intention and attention cues from the surgeon's behavior and combine them with sensory data from a commodity depth camera. The developed interface was tested in a usability experiment to assess the effectiveness of the new interface. An image navigation and manipulation task was performed, and the gesture recognition accuracy, false positives and task completion times were computed to evaluate system performance. Experimental results show that gesture interaction and surgeon behavior analysis can be used to accurately navigate, manipulate and access MRI images, and therefore this modality could replace the use of keyboard and mice-based interfaces.

Developing a Framework for Predicting Upper Extremity Muscle Activities, Postures, Velocities, and Accelerations During Computer Use: The Effect of Keyboard Use, Mouse Use, and Individual Factors on Physical Exposures

Prediction models were developed based on keyboard and mouse use in combination with individual factors that could be used to predict median upper extremity muscle activities, postures, velocities, and accelerations experienced during computer use. In the laboratory, 25 participants performed five simulated computer trials with different amounts of keyboard and mouse use ranging from a highly keyboard-intensive trial to a highly mouse-intensive trial. During each trial, muscle activity and postures of the shoulder and wrist and velocities and accelerations of the wrists, along with percentage keyboard and mouse use, were measured. Four individual factors (hand length, shoulder width, age, and gender) were also measured on the day of data collection. Percentage keyboard and mouse use explained a large amount of the variability in wrist velocities and accelerations. Although hand length, shoulder width, and age were each significant predictors of at least one median muscle activity, posture, velocity, or acceleration exposure, these individual factors explained very little variability in addition to percentage keyboard and mouse use in any of the physical exposures investigated. The amounts of variability explained for models predicting median wrist velocities and accelerations ranged from 75 to 84% but were much lower for median muscle activities and postures (0–50%). RMS errors ranged between 8 to 13% of the range observed. While the predictions for wrist velocities and accelerations may be able to be used to improve exposure assessment for future epidemiologic studies, more research is needed to identify other factors that may improve the predictions for muscle activities and postures.

Are there Differences in Force Exposures and Typing Productivity between Touchscreen and Conventional Keyboard?

As the use of tablets is becoming increasingly prevalent, it is important to understand how using a touchscreen (virtual) keyboard affects typing forces, productivity and comfort. Thus, the objective of this study was to investigate whether there were differences in typing forces, typing productivity and users’ discomfort between virtual and conventional keyboards. A total of 19 subjects (10 males and 9 females) typed for 10 minutes on a virtual keyboard and two conventional keyboards. The results showed that virtual keyboard use resulted in lower typing forces (p < 0.0001), lower typing performance (p < 0.0001), and higher subjective discomfort at the hand/wrist and the neck/shoulder (p < 0.0001). The results indicate that using a virtual keyboard may not cause any detrimental effect on physical exposures, but may increase musculoskeletal discomfort on the upper extremities and neck/shoulder regions; therefore, appropriate interventions should be considered for the prolonged use of a virtual keyboard.

Cumulative keyboard strokes: a possible risk factor for carpal tunnel syndrome

BackgroundContradictory reports have been published regarding the association of Carpal Tunnel Syndrome (CTS) and the use of computer keyboard. Previous studies did not take into account the cumulative exposure to keyboard strokes among computer workers. The aim of the present study was to investigate the association between cumulative keyboard use (keyboard strokes) and CTS.MethodsEmployees (461) from a Governmental data entry & processing unit agreed to participate (response rate: 84.1 %) in a cross-sectional study. Α questionnaire was distributed to the participants to obtain information on socio-demographics and risk factors for CTS. The participants were examined for signs and symptoms related to CTS and were asked if they had previous history or surgery for CTS. The cumulative amount of the keyboard strokes per worker per year was calculated by the use of payroll’s registry. Two case definitions for CTS were used. The first included subjects with personal history/surgery for CTS while the second included subjects that belonged to the first case definition plus those participants were identified through clinical examination.ResultsMultivariate analysis used for both case definitions, indicated that those employees with high cumulative exposure to keyboard strokes were at increased risk of CTS (case definition A: OR = 2.23;95 % CI = 1.09-4.52 and case definition B: OR = 2.41; 95%CI = 1.36-4.25). A dose response pattern between cumulative exposure to keyboard strokes and CTS has been revealed (p < 0.001).ConclusionsThe present study indicated a possible association between cumulative exposure to keyboard strokes and development of CTS. Cumulative exposure to key-board strokes would be taken into account as an exposure indicator regarding exposure assessment of computer workers. Further research is needed in order to test the results of the current study and assess causality between cumulative keyboard strokes and development of CT.

Observed differences in upper extremity forces, muscle efforts, postures, velocities and accelerations across computer activities in a field study of office workers

This study, a part of the PRedicting Occupational biomechanics in OFfice workers (PROOF) study, investigated whether there are differences in field-measured forces, muscle efforts, postures, velocities and accelerations across computer activities. These parameters were measured continuously for 120 office workers performing their own work for two hours each. There were differences in nearly all forces, muscle efforts, postures, velocities and accelerations across keyboard, mouse and idle activities. Keyboard activities showed a 50% increase in the median right trapezius muscle effort when compared to mouse activities. Median shoulder rotation changed from 25 degrees internal rotation during keyboard use to 15 degrees external rotation during mouse use. Only keyboard use was associated with median ulnar deviations greater than 5 degrees. Idle activities led to the greatest variability observed in all muscle efforts and postures measured. In future studies, measurements of computer activities could be used to provide information on the physical exposures experienced during computer use. Practitioner Summary: Computer users may develop musculoskeletal disorders due to their force, muscle effort, posture and wrist velocity and acceleration exposures during computer use. We report that many physical exposures are different across computer activities. This information may be used to estimate physical exposures based on patterns of computer activities over time.

Usability Test of 3Dconnexion 3D Mice Versus Keyboard+Mouse in Second Life Undertaken by People with Motor Disabilities due to Medullary Lesions

The use of keyboard and mouse combinations to navigate 3D environments of virtual worlds requires the coordination of both hands in order for the 2D degrees of motion of the mice to transform into the variety of motions available in a 3D space. Such coordination may pose a challenge to people with motor disabilities. 3D controllers known as “3D mice” are presented by manufacturers as significant interface alternatives. To establish the feasibility of such claims, we have conducted a usability test of two 3D mice marketed by 3Dconnexion, in parallel with a keyboard+mouse test. The 10 participants had motor disabilities due to medullary lesions on vertebrae C5-D11, and performed 13 different tasks in the Second Life virtual world: 5 participants used 3D mice, 5 used keyboard+mouse. We have concluded that 2-3 of the 5 most challenging tasks in the keyboard+mouse combination become less challenging using 3D mice. Participants’ feedback was more positive regarding 3D mice, but with significant differences between mice. Contrary to our initial expectations, the least stable mouse, Space Navigator, originated the best feedback.

Usability analysis of 2D graphics software for designing technical clothing

With the advent of technology, the computer became a working tool increasingly present in companies. Its purpose is to increase production and reduce the inherent errors in manual production. The aim of this study was to analyze the usability of 2D graphics software in creating clothing designs by a professional during his work. The movements of the mouse, keyboard and graphical tools were monitored in real time by software Camtasia 7® installed on the user's computer. To register the use of mouse and keyboard we used auxiliary software called MouseMeter®, which quantifies the number of times they pressed the right, middle and left mouse's buttons, the keyboard and also the distance traveled in meters by the cursor on the screen. Data was collected in periods of 15 minutes, 1 hour and 8 hours, consecutively. The results showed that the job is considered repetitive and high demands physical efforts, which can lead to the appearance of repetitive strain injuries. Thus, the goal of minimizing operator efforts and thereby enhance the usability of the examined tool, becomes imperative to replace the mouse by a device called tablet, which also offers an electronic pen and a drawing platform for design development.

An Average Facial Color Image Avatar System for the Analysis by Synthesis of Affect Display by Dynamic Facial Color and Expression

In this study, we design an average facial color image avatar called FaceAvatar, and develop the system for the analysis by synthesis of affect display by dynamic facial color and expression. More specifically, FaceAvatar is designed by applying texture mapping to the average facial color image in a 3D wire-frame model that estimates various feature points on the facial surface of the average facial color image. The developed system enables laughing operation of FaceAvatar through the use of a computer keyboard. Further, the proposed dynamic model of facial color and expression under laughing emotion are analyzed synthetically by using the system. The effectiveness of the system for the analysis by synthesis is demonstrated by sensory evaluation.

Ambiguous keyboards for AAC

Purpose – “Ambiguous keyboards” and “disambiguation processes” are becoming universally recognised through the popularisation of “predictive text messaging” on mobile phones. As this paper shows, although originating in the AT and AAC fields, these terms and techniques no longer appear to be widely understood or adopted by practitioners or users. The purpose of this paper is to introduce these techniques, discussing the research and theory around them, and to suggest them as AT and AAC strategies to be considered by practitioners and users.Design/methodology/approach – This is a conceptual paper that describes the use of ambiguous keyboards and disambiguation. The hypothesis of the paper is that ambiguous keyboards and disambiguation processes offer potential to increase the efficiency and effectiveness of AAC and should thus be considered further in research and practice.Findings – The two broad methods for removing the ambiguity from the output of an ambiguous keyboard are presented. A summary of the li...