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Zmiany w podejściu do ciężkości pracy i pracy przy komputerze

Jóźwiak Zbigniew

Promotor BHP

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2021

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nr 9

48--51

PL

Z jakimi zmianami borykają się praktycy z branży BHP w przypadku pomiaru wydatku energetycznego oraz pracy przy komputerze? W artykule omawiamy powyższe problemy i zastanawiamy się nad ich ergonomicznym rozwiązaniem.

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Effect of Different Types of Rest-Break Interventions on Neck and Shoulder Muscle Activity, Perceived Discomfort and Productivity in Symptomatic VDU Operators: A Randomized Controlled Trial

Nakphet N., Chaikumarn M., Janwantanakul P.

International Journal of Occupational Safety and Ergonomics

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2014

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Vol. 20, No. 2

339--353

EN

Objective. This study evaluated the effect of different types of activities during rest-break interventions on neck and shoulder muscle activity, muscle discomfort and productivity among symptomatic video display unit (VDU) operators performing prolonged computer terminal work. Study design and setting. Randomized controlled trial was used. Thirty symptomatic VDU operators were randomly assigned to 2 active break groups (stretching and dynamic movement) and a reference group. The subjects performed the same typing task for 60 min and received 3-min breaks after each 20 min of work. Root mean square and median frequency were calculated for neck and shoulder muscle activity. Muscle discomfort was measured with Borg’s CR-10 scale. Productivity was measured by counting words. Results. There were no significant differences between the types of activities during breaks on neck and shoulder muscle activity, muscle discomfort or productivity. However, there was a significant difference in the level of muscle discomfort over time. Conclusions. Three types of activity during breaks showed a favourable effect on neck and shoulder muscle activity and productivity, and a positive effect on muscle discomfort in symptomatic VDU operators.

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Postural and Muscular Responses While Viewing Different Heights of Screen

Lee T. H., Liu T. Y.

International Journal of Occupational Safety and Ergonomics

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2013

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Vol. 19, No. 2

251--258

EN

This study aimed to examine the effects of visual display terminal (VDT) viewing angle on human postural angle and muscular activity. The participants’ neck, thoracic bending, and trunk inclination angles; and the activity of sternocleidomastoid, trapezius, splenius capitis, and erector spinae at 5 viewing angles (+400, +200, 00, –200, and –400) of a VDT screen were collected for 1 min. This study showed that neck and thoracic bending angles increased with viewing angle, while viewing angle did not significantly affect trunk inclination angle. In addition, the activity of trapezius and erector spinae increased when viewing a higher or lower VDT screen height compared with viewing a horizontal VDT screen height; however, the activity of splenius capitis decreased with viewing angle.

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Reliability of a Questionnaire and an Ergonomic Checklist for Assessing Working Conditions and Health at Call Centres

Norman K., Alm H., Tornqvist E. W., Toomingas A.

International Journal of Occupational Safety and Ergonomics

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2006

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Vol. 12, No. 1

53--68

EN

Background. The purpose was to study the test-retest reliability and internal consistency of questions in a questionnaire concerning working conditions and health and the inter-rater reliability of observations and measurements according to an ergonomic checklist. Method. Fifty-seven operators participated in a retest questionnaire and 58 operators participated in an inter-observer test. Results. The questions had fair to good or higher reliability in 142 of the total of 312. Twenty-seven of the total of 44 variables in the ergonomic checklist were classified as having fair to good or higher reliability. Conclusions. About half of the questions had fair to good or higher reliability and can be recommended for further analyses. The majority of variables in the ergonomic checklist were classified as having fair to good or higher reliability. Low reliability does not necessarily indicate that the reliability of the test, per se, is low but may signify that the conditions measured vary over time or that the answers are aggregated in one part of the scale.

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Symptoms and Clinical Findings From the Musculoskeletal System Among Operators at a Call Centre in Sweden-A 10-Month Follow-Up Study

Toomingas A., Nilsson T., Hagberg M., Hagman M., Tornqvist E. W.

International Journal of Occupational Safety and Ergonomics

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2003

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Vol. 9, No. 4

405--418

EN

The musculoskeletal health among 57 operators at 1 call centre in Sweden was studied with 10 monthly follow-ups, parallel to a reference group of 1,226 professional computer users in other occupations. Operators at this call centre were more symptom-loaded than the other professional computer users in spite of their younger age and shorter exposure to computer work. Symptoms were long-lasting or recurrent. Muscle tenderness and nerve affections in the neck-shoulder region were the most common specific findings and diagnoses at medical examination of incident symptom cases. More extensive studies should be done on the working conditions and health status among call centre workers.

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Effect of Subjective and Objective Workload on Asthenopia at VDU Workplaces

Studeli T., Menozzi M.

International Journal of Occupational Safety and Ergonomics

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2003

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Vol. 9, No. 4

441--451

EN

An ergophthalmological tool has been developed to investigate effects of subjective and objective workload on work-related visual complaints (asthenopia). In field studies on different visual display unit (VDU) workplaces effects of objective and subjective workload, work intensity, and work breaks (5–9 min/hour) could be found. It could be shown that during the first hours of VDU work, asthenopic complaints have the tendency to follow effective workload. With increasing working time the effect of a general and visual fatigue overlaps other reported visual complaints in the majority of cases.

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Comparison Between the Strain Indicator HRV of a Head-Based Virtual Retinal Display and LC-Head Mounted Displays for Augmented Reality

Oehme O., Schmidt L., Luczak H.

International Journal of Occupational Safety and Ergonomics

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2003

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Vol. 9, No. 4

419--430

EN

Augmented Reality uses Head Mounted Displays (HMD) to overlay the real word with additional virtual information. Virtual Retinal Displays (VRD), a new display technology, no longer requires Liquid Crystal Displays (LCD). VRD technology addresses the retina directly with a single laser stream of pixels. There are no studies on the user’s informational strain in this new VRD technology. Various papers have shown that Heart Rate Variability (HRV) is a valid indicator for the user’s informational strain. An empirical test revealed no difference in the user’s HRV between VRD technology and LCD technology. Consequently, there seems to be a comparable user informational strain regarding the display types.

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Biomechanical Stresses in Computer-Aided Design and in Data Entry

Cail F., Aptel M.

International Journal of Occupational Safety and Ergonomics

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2003

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Vol. 9, No. 3

235--255

EN

A study of the risk factors of musculoskeletal disorders (MSDs) of the upper limbs was carried out on 2 populations, 1 performing a computer-aided design (CAD) task and the other performing a data entry task. A questionnaire on MSD complaints and working life was completed by a sample of each population. Biomechanical measurements of the forces, the angles, and the repetitiveness of movements of the upper limbs were carried out on some operators in each sample. It emerged that complaints of the upper limbs seem to be linked to the use of input devices. The grip forces exerted when using the keyboard and mouse were higher in CAD than in data entry.

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An Attempt at Preventing Asthenopia Among VDT Workers

Omori M., Watanabe T., Takai J., Takada H., Miyao M.

International Journal of Occupational Safety and Ergonomics

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2003

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Vol. 9, No. 4

453--462

EN

We report the results of 3 surveys of visual display terminal (VDT) users who took a minibreak during which they viewed a stereoscopic image of a repeating parallel pattern showing planets. The single image stereogram method employed is called Stretch Eye™, and we evaluated the effects of Stretch Eye™ on asthenopia. An accommodative relaxation of about 1 D was observed in participants while they were gazing at the image. The employees of 2 information technology companies were evaluated according to a visual analogue scale (VAS) for subjective symptoms of asthenopia and eyesight. The results showed that Stretch Eye™ was effective in easing visual fatigue due to VDT work and it improved eyesight under working conditions.

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A New Approach to the Mouse Arm Syndrome

Ullman J., Kangas N., Ullman P., Wartenberg F., Ericson M.

International Journal of Occupational Safety and Ergonomics

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2003

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Vol. 9, No. 4

463--477

EN

OBJECTIVES: The study validates a new computer mouse concept. The tested device is a small mouse with a pivoting pen-shaped handle. The hypothesis behind the design is the assumptions that the pen grip requires less static tension than the normal mouse grip and that fine-motor, high precision tasks normally are done with finger movements with forearm at rest. METHODS: Four muscles were monitored with electromyography (EMG) during work with a new mouse and with a traditional mouse. RESULTS: EMG activity was significant lower, in M. pronator teres - 46%, M. extensor digitorum - 46%, M. trapezius - 69%, and M. levator scapulae - 82%, during work with the new mouse as compared to the traditional mouse. CONCLUSION: Altering the design of the computer mouse can significantly reduce muscular tension.

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Computer Usage With Cold Hands; An Experiment With Pointing Devices

Blomkvist A. C., Gard G.

International Journal of Occupational Safety and Ergonomics

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2000

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Vol. 6, No. 4

429--450

EN

Computers are used in the outdoors and in connection with cold store work. Cold hand and fingers limit data input, as studied here. Six input devices; trackballs, pens, and a mouse were tested by 19 participants in a Fitts' target acquisition task with 2 target sizes under 2 experimental conditions; warm and cold right hand. Measures were acquisition times, number of errors, participant's preferences, and observed handling of the devices. Effects of device, target size, and cold were significant. Learning and attempts to improve handgrip were confirmed. Large enough targets, a thick pen, and a mouse make computer work practicable in the cold. Direct visual feedback, as with pen on template with target images, shortened acquisition times by half a second.