Keyboard Work Research Articles

Variation Process in G. A. Frescobaldi's Cento partite sopra passacagli (1637)

Cento partite sopra passacaglia (1637), the longest keyboard work by Girolamo Frescobaldi (1583–1643), consisting of over 100 tonic-dominant harmonic cycles, exhibits the composer's expansive conception of the art of variation. This article demonstrates that the overarching formal structure in Cento partite is delineated by interconnected variation processes involving the relative stability/instability of the parameters of genre (passacaglia, ciacona, and corrente) and key (motion away from and returning to the original key of D minor). These large-scale variation processes relate to and affect rhythmic and motivic content and variation on the local (variation-to-variation) level.

A Whole Carnal Stereophony: The Wooster Group Stages Brecht

A Whole Carnal Stereophony: The Wooster Group Stages Brecht

The Dynamic Computer Workstation-A Pilot Study of Clinical and Biochemical Investigation during Work at Static Respectively Mobile Keyboards.

A large and increasing number of the work force in the population spend their work hours at the keyboard. There is evidence that repetitive high levels of static work, or extreme working postures involving the neck–shoulder muscles are an increased risk for chronic neck–shoulder pain. The aim of this study was to investigate the effect of dynamic computer working (DCW), using a mobile application to the desk surface, on pain characteristics and biomarkers in office workers. We included 10 female subjects. All subjects answered questionnaires about general health, pain intensity and characteristics. The pressure pain threshold (PPT), neck range and motion, neck and shoulder strength were measured. Microdialysis was conducted in trapezius muscle. Measurements were performed before and 4 weeks after DCW. Multivariate analysis, orthogonal partial least square discriminate analysis (OPLS-DA) and univariate analysis paired test, Wilcoxon, was performed. There was significant improvement in reported neck pain, quality of life, and psychological distress after 4 weeks DCW. The PPT and strength in neck and shoulder were significantly increased after DCW. A significant OPLS-DA model showed clear separation between the samples collected before and after 4 weeks DCW. In conclusion, these results show that keyboard work at a movable desk application might decrease the risk of repetitive strain injuries in the neck and shoulder muscles.

Finite element simulation of the mechanical impact of computer work on the carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is a clinical disorder resulting from the compression of the median nerve. The available evidence regarding the association between computer use and CTS is controversial. There is some evidence that computer mouse or keyboard work, or both are associated with the development of CTS. Despite the availability of pressure measurements in the carpal tunnel during computer work (exposure to keyboard or mouse) there are no available data to support a direct effect of the increased intracarpal canal pressure on the median nerve.This study presents an attempt to simulate the direct effects of computer work on the whole carpal area section using finite element analysis. A finite element mesh was produced from computerized tomography scans of the carpal area, involving all tissues present in the carpal tunnel.Two loading scenarios were applied on these models based on biomechanical data measured during computer work. It was found that mouse work can produce large deformation fields on the median nerve region. Also, the high stressing effect of the carpal ligament was verified. Keyboard work produced considerable and heterogeneous elongations along the longitudinal axis of the median nerve. Our study provides evidence that increased intracarpal canal pressures caused by awkward wrist postures imposed during computer work were associated directly with deformation of the median nerve. Despite the limitations of the present study the findings could be considered as a contribution to the understanding of the development of CTS due to exposure to computer work.

Design of a Functional Signal Generator Based on MAX038 and Microcontroller

Based on SCM STC89C52 and MAX038, a function signal generator for generating a frequency and amplitude can be programmed to adjust the sine wave, square wave and triangular wave signal. MAX038 function generator with a small amount of peripheral devices are responsible for generating waveforms, which then are input into the LM6361 wideband voltage amplifier and a power amplifier is output. Master STC89C52 is responsible for selecting and managing the waveform types, frequency adjustment, output amplitude adjustment, LCD, and keyboard work of each module operation.

Effect of Sustained Typing Work on Changes in Scapular Position, Pressure Pain Sensitivity and Upper Trapezius Activity

The aim of this study was to investigate the effects of sustained computer keyboard typing on the human musculoskeletal system by assessing the pressure-pain threshold (PPT), scapular position and activation of the upper trapezius. Vertical and horizontal positional changes of the scapular were measured with a palpation meter before and after keyboard work, and the PPT was measured using a pressure algometer. Activation of the upper trapezius during 20 minutes of computer keyboard work was measured by electromyography, and four consecutive 5-minute segments were analyzed. The vertical distance from the seventh cervical process to the acromion, and the horizontal distance from the inferior angle to the same level of the spinal process were significantly increased after keyboard typing work compared with before keyboard typing work (p<0.05). The average value of the upper trapezius activity increased with increased time at the keyboard. The percent reference voluntary contraction of phase 1 (from start to 5 minutes) was lower than those of phase 2 (from 5 to 10 minutes), and phase 3 (from 10 to 15 minutes) (p<0.05). We observed that sustained computer work changed the scapular position in the stretched upper trapezius. To prevent musculoskeletal problems in the shoulder region, posture reeducation during computer work should be considered in terms not only of neck and trunk posture, but also of scapular position.

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.

Computer use and adverse health problems – are clinicians concerned?

The use of computers is prevalent throughout many societies today, with people from all age groups, both sexes, and in many careers having regular contact with them either in the home or at the workplace. Existing scientific evidence clearly demonstrates that poor posture, greater muscle activity and musculoskeletal pain, as well as psychological problems such as internet addiction and antisocial personality disorder, are widely found among habitual users of computers. It is important that the negative consequences of current technology on physical and psychological wellbeing are not ignored, and therefore prevention and rehabilitation of these health effects, in computer users, must be urgently considered by clinicians. Pain and discomfort in the upper body, particularly the neck and shoulders, has been found to correlate with habitual computer usage. A further study by Harris and Straker of students who regularly used a laptop computer found reports of discomfort from usage (60%) and also from carrying the laptop (63%). Such musculoskeletal complaints were linked to improper ergonomics and poor posture during computer use. Poor adaptive posture was also seen in children and young adults, with a wide variety of postures employed, although these age groups differed markedly from the postures adapted by adults. Poor posture was also clearly associated with tall people who used the type of small screen normally seen on laptop computers, and commonly sat at inappropriate heights for their leg lengths, suggesting that it would be better to place such devices on a raised platform. Computer users typically report various musculoskeletal complaints. Neck, back and shoulder pain has been found in adolescent computer users. The one year prevalence of neck and shoulder pain, the most commonly reported somatic pain syndrome, is 58 cases per 100 persons. Neck pain and clinical abnormality has also been correlated with greater head rotation and inclination. Similarly, upper torso pain and severe stiffness has been reported by computer users who have high head rotation and keyboard height above elbow level. In addition, low back pain was reported at least once during the working day in female computer users, and the risk factor for low back pain, and pain exacerbation from prolonged sitting during computer use, was calculated as an odds ratio of 1.1–1.5. Back discomfort has been shown, with statistical significance, to be correlated with a downward viewing angle. However, the highest level of muscular activity was found in erect sitting with forward inclination of the body in visual display technology (VDT) workers, and increased stretching of passive structures in the back was caused by poor posture. Existing evidence suggests that the negative effects on muscular activities were due to the fact that different sitting postures during computer use led to different trunk muscle activation. Thoracic upright sitting increased co-activation of global back muscles, whereas lumbar-pelvic upright sitting increased coactivation of local muscle groups. Similarly, neck and shoulder muscles, particularly the descending aspect of the trapezius muscles, were distressed with additional effects on other muscles such as the longissimus capitis. It is likely that an increase in trapezius muscle activity is found when using a standard desk and workplace board (forearm support) compared to a standard desk, although this may be dependent on the elbow flexion angle. The dynamic and sustained contraction of the small muscles of the forearms and hands, and the shoulder, neck and back muscles, during word processor work may be one of the causative factors in neck and shoulder problems. It has been clearly demonstrated that the trapezius muscles engage in static contraction during keyboard work, and that fatigue of the shoulder muscles occurs rapidly during simple shoulder movement even when there is an application of mass on only one arm. Hand/arm symptoms in computer users were found to be mainly caused by poor non-neutral wrist Correspondence to: Pattariya Intolo, Faculty of Health Sciences, Srinakhawirot University, Origkharak, Nakhonnayoik 26120, Thailand. Email: pattariy@swu.ac.th

Wasteaminute.com: Notes on Office Work and Digital Distraction

Wasteaminute.com: Notes on Office Work and Digital Distraction

Does familiarity with computers affect computerized neuropsychological test performance?

The purpose of this study was to determine whether self-reported computer familiarity is related to performance on computerized neurocognitive testing. Participants were 130 healthy adults who self-reported whether their computer use was “some” (n = 65) or “frequent” (n = 65). The two groups were individually matched on age, education, sex, and race. All completed the CNS Vital Signs (Gualtieri & Johnson, 2006b) computerized neurocognitive battery. There were significant differences on 6 of the 23 scores, including scores derived from the Symbol–Digit Coding Test, Stroop Test, and the Shifting Attention Test. The two groups were also significantly different on the Psychomotor Speed (Cohen's d = 0.37), Reaction Time (d = 0.68), Complex Attention (d = 0.40), and Cognitive Flexibility (d = 0.64) domain scores. People with “frequent” computer use performed better than people with “some” computer use on some tests requiring rapid visual scanning and keyboard work.

Computer keyswitch force–displacement characteristics affect muscle activity patterns during index finger tapping

This study examined the effect of computer keyboard keyswitch design on muscle activity patterns during finger tapping. In a repeated-measures laboratory experiment, six participants tapped with their index fingers on five isolated keyswitch designs with varying force–displacement characteristics that provided pairwise comparisons for the design factors of (1) activation force (0.31 N vs. 0.59 N; 0.55 N vs. 0.93 N), (2) key travel (2.5 mm vs. 3.5 mm), and (3) shape of the force–displacement curve as realized through buckling-spring vs. rubber-dome switch designs. A load cell underneath the keyswitch measured vertical fingertip forces, and intramuscular fine wire EMG electrodes measured muscle activity patterns of two intrinsic (first lumbricalis, first dorsal interossei) and three extrinsic (flexor digitorum superficialis, flexor digitorum profundus, and extensor digitorum communis) index finger muscles. The amplitude of muscle activity for the first dorsal interossei increased 25.9% with larger activation forces, but not for the extrinsic muscles. The amplitude of muscle activity for the first lumbricalis and the duration of muscle activities for the first dorsal interossei and both extrinsic flexor muscles decreased up to 40.4% with longer key travel. The amplitude of muscle activity in the first dorsal interossei increased 36.6% and the duration of muscle activity for all muscles, except flexor digitorum profundus, decreased up to 49.1% with the buckling-spring design relative to the rubber-dome design. These findings suggest that simply changing the force–displacement characteristics of a keyswitch changes the dynamic loading of the muscles, especially in the intrinsic muscles, during keyboard work.

Incidence and suspected cause of work-related musculoskeletal disorders, United Kingdom, 1996–2001

Musculoskeletal conditions are the most common self-reported work-related disease, with high costs incurred from long-term disability. In the United Kingdom, occupational physicians and rheumatologists have been reporting new cases of work-related musculoskeletal disorders to voluntary surveillance schemes since 1996. To estimate population incidence rates for work-related musculoskeletal disorders reported by rheumatologists and occupational physicians by occupation and industry, in relation to tasks and movements suspected as causal. Estimated average annual incidence rates were calculated for nine main job categories and eight industrial groups; Labour Force Survey figures were used as the denominator for rheumatologists, and a special survey for the occupational physicians. These were then related to tasks and movements reported as causal. Between October 1997 and the end of 2001, an estimated 2,599 new cases/year were reported by rheumatologists, and from January 1996, 5,278 cases/year by occupational physicians. Average annual rates overall were 94 per million for rheumatologists and 1,643 per million for occupational physicians (a 17-fold difference). Jobs at highest risk for the upper limb were primarily clerical, craft-related and machine work. Tasks associated with upper limb disorders and with neck and back problems were predominantly keyboard work and heavy lifting, and in craft-related occupations with gripping or holding tools. Jobs at risk and the associate tasks were identified which should assist prevention, but the extent to which these factors were causal or aggravating previous injury requires further study. The much higher rates reported by occupational physicians reflect, in part, the type of industries they served.

A comparison of symptomatic and asymptomatic office workers performing monotonous keyboard work—1: Neck and shoulder muscle recruitment patterns

Work-related neck and upper limb disorders (WRNULD) are common problems among office workers who use computers intensively and maintain prolonged static postures. These disorders have often been attributed to result from sustained muscle activity in the neck–shoulder musculature. The present study examined whether symptomatic subjects exhibited the same muscle activity patterns as asymptomatic controls when they performed a prolonged computer task under the same conditions. Surface electromyography (EMG) of four major neck–shoulder muscles were compared between a Case Group ( n = 23 ) and a Control Group ( n = 20 ) of female office workers. The Case Group had higher activity in the right upper trapezius (UT) while the Control Group had more symmetrical muscle activity between left and right UT. The Case subjects could also be differentiated into “High Discomfort” and “Low Discomfort” sub-groups based on their discomfort scores. The High Discomfort Group had significantly higher right UT activity compared to the Low Discomfort and Control Groups. Results suggested that symptomatic individuals had altered muscle recruitment patterns that persisted throughout the sustained occupational task, while discomfort increased with time-at-task. These findings indicate that altered muscle recruitment patterns observed in the symptomatic subjects preceded the onset of task discomfort, and this finding may have important implications for the etiology of WRNULD.

A comparison of symptomatic and asymptomatic office workers performing monotonous keyboard work—2: Neck and shoulder kinematics

Prolonged static posture has been identified as a major risk factor for work-related neck and upper limb disorders (WRNULD) in computer users. Previous research has mainly examined working postures in healthy pain-free individuals. The present study examined whether symptomatic subjects exhibited the same kinematic patterns as asymptomatic controls during a prolonged computer task. In a Case–Control comparison, female office workers performed the same computer task using the same adjustable computer workstation for 1 h. Three-dimensional (3D) kinematics were measured in the head–neck, thorax and shoulder (upper arm) segments. Case Group subjects ( n = 21 ) displayed trends for increased head–neck flexion angles and greater ranges of movements than the Control Group ( n = 17 ). There were also small but significant differences between groups in side flexion and rotation angles of the head-neck region. The shoulder joints displayed significantly greater flexion and abduction angles on the right in both groups, although no group differences were observed. The increased neck flexion angles were associated with significantly higher activity in the upper trapezius muscle and with neck and shoulder discomfort. The individual differences in postural habits appeared to be independent of the physical environment. These results suggest motor control changes are associated with the presence of WRNULD.

An evaluation of voice recognition software for use in interview-based research: a research note

This small research project investigated whether it was feasible and beneficial to use voice recognition software to transcribe tape recordings of multiple voices. Two methods of use were trialed and it rapidly became clear that the ‘listen and repeat’ method was the leading contender. Through an iterative process, we developed guidelines to increase the usefulness of the software for research purposes, the main points of which are incorporated in this report. Our results suggest that voice recognition software has many advantages, and few disadvantages. It is of particular use for researchers for whom prolonged keyboard work is difficult or unsafe and for researchers with slow typing speeds, but any researcher may find it advantageous.

Risk factors for persistent elbow, forearm and hand pain among computer workers

This study examined the influence of work-related and personal factors on the prognosis of "severe" elbow, forearm, and wrist-hand pain among computer users. In a 1-year follow-up study of 6943 computer users, 673 (10%) participants reported "quite a lot" or more trouble due to elbow, forearm, or wrist-hand pain during the 12 months preceding the baseline questionnaire. Pain status (recovery versus persistence) at follow-up was examined in relation to computer work aspects and ergonomic, psychosocial, and personal factors by questionnaire. In addition, data on objectively recorded computer usage were available for 42% of the participants during the follow-up, measured by means of a program (WorkPaceRecorder) installed on their computers. During the follow-up, two-thirds of the baseline cases improved to some degree, but only one-third experienced substantial improvement. The prognosis was not influenced by mouse or keyboard work (time, speed, micropauses, and average activity periods) or ergonomic workplace conditions. Keyboard times, however, were very low. Pain in other regions was a predictor of persistent arm pain. Except for time pressure, female gender, and type-A behavior, the prognosis seemed independent of psychosocial workplace factors and personal factors. A few cases with severe pain were affected at a level which could be compared to clinical pain conditions. Our results do not support the hypothesis that computer work activity or ergonomic conditions influence the prognosis of severe arm pain. This result is somewhat surprising and should be tested in other studies. Pain in other regions implies a poorer prognosis for arm pain.

A New Keyboard Work by Giovanni Gabrieli and the Relevance of Its Compositional Technique

There is much evidence that our picture of Giovanni Gabrieli's output is incomplete, and the frequency with which new works have emerged in recent decades suggests that there is still scope for further discoveries. This article focuses on a new keyboard ricercar by Giovanni Gabrieli preserved in the Staatsbibliothek zu Berlin Preusischer Kulturbesitz. The composition, which has previously not been mentioned in the literature, ranks among the most eloquent and impressive of Gabrieli's keyboard works. Until recently, it was located in the binding of an eighteenth-century book. The sources of the work, and its provenance, compositional technique, and relationships to contemporary keyboard pieces are discussed.

Epidemiology of musculoskeletal disorders among computer users: lesson learned from the role of posture and keyboard use

Reports in the scientific literature and lay press have suggested that computer users are at increased risk of upper extremity musculoskeletal disorders (MSDs). Early studies often found elevated rates of MSD outcomes among keyboard users when compared to non-users. Attention soon focused on specific aspects of keyboard work that might be responsible for the observed rate increase. In this review, the epidemiological evidence examining associations between MSD outcomes and computer user posture and keyboard use intensity (hours of computer use per day or per week) are examined. Results of epidemiological studies of posture and MSD outcomes have not been entirely consistent. Reasons for the inconsistency in results include cross-sectional study design (with possible failure to assure that measured exposure preceded health effect), imprecision of posture measures used, and difficulties involved in analyzing multiple related variables. Despite the inconsistencies, it appears from the literature that posture is an independent risk factor of modest magnitude for MSDs among computer users. It appears that lowering the height of the keyboard to or below the height of the elbow and resting the arms on the desk surface or chair armrests is associated with reduced risk of neck and shoulder MSDs. Results of epidemiological studies examining computer use (hours keying per day or per week) are more consistent than those examining posture, although some inconsistency is observed. Reasons for the inconsistency include possible selective survival bias resulting from cross-sectional study design, differences in exposure categorization, and possible interaction with other exposure variables. Overall, the literature shows that daily or weekly hours of computer use is more consistently associated with hand and arm MSDs than with neck and shoulder MSDs.

Recurrent Hand/Wrist Problems and Organisation of Work Involving Keyboard Use, Physical Strain and Work-Related Mental Job Stress

Job design issues have been implicated in the development of work-related neck and upper limb musculoskeletal disorders. This paper describes the results from about 2000 computer users involved in a base-line of a prospective study in the UK. The data support the ecological model of musculoskeletal disorders proposed in 1996 by Steve Sauter and Naomi Swanson. A sense of physical strain from performing 4+ hours of keyboard work per day and perceiving the job to be mentally stressful mediates the exposure-effect relationship between keyboard work and recurrent hand/wrist problems. This study has implications for job design. It supports the recommendations that jobs involving computer work should limit typing to less than 4 hours a day and organisational factors should be addressed to avoid mental stress. In addition, feedback regarding the physical aspects of the job design (organisation of work and physical workstation layout) may further reduce risks.

Examination of and Intervention for a Patient With Chronic Lateral Elbow Pain With Signs of Nerve Entrapment

Lateral elbow pain has several causes, which can make diagnosis difficult. The purpose of this case report is to describe the examination of and the intervention for a patient with chronic lateral elbow pain who had signs of nerve entrapment. The patient was a 43-year-old woman who had right lateral elbow pain for about 4 months, which she attributed to extensive keyboard work on a computer. She had a reduction in joint passive range of motion during "neural tension testing," an examination procedure to detect nerve entrapment. This sign, in combination with other findings, suggested that the patient had a mild entrapment of the deep radial nerve (radial tunnel syndrome). The patient was treated 14 times over a 10-week period with "neural mobilization techniques," which are designed to free nerves for movement; ultrasound; strengthening exercises; and stretching. The patient had minimal symptoms at discharge, was pain-free, and had resumed all activities at a 4-month follow-up visit. Neural tension testing may be a useful examination procedure and mobilization may be useful for intervention for patients who have lateral elbow pain.