[Assessment of musculoskeletal disorders using a questionnaire]. / Erfassung muskuloskeletaler Beschwerden mittels Fragebogen.

The standardized illustrated questionnaire on musculoskeletal disorders of the Japanese Committee on Occupational Cervico-branchial Disorders was translated into German. This questionnaire, composed of 37 items about the occurrence (never/seldom, occasionally, almost daily) of symptoms (pain, stiffness, fatigue) in twelve body regions, was used together with medical examinations (pressure points), and further information was gathered on the consumption of analgetics and medical visits prompted by musculoskeletal symptoms. The questionnaire's reliability and validity were tested in 644 persons from twelve occupational groups within the service sector. Factor analysis showed that symptoms can be grouped into four distinct regions of occurrence: neck/shoulder/area, back/low back, and both left and right upper extremities. Indices based on these regions are consistent (Cronbach alpha approximately 0.8). Palpation findings steadily increase with increasing index values. The consumption of medicaments and medical visits positively correlate with the indices. Consequently the questionnaire is judged to be a valid instrument for studying musculoskeletal disorders at the workplace.

Preferred VDT workstation settings, body posture and physical impairments.

In a field study an adjustable VDT workstation was given to each of the 68 operators for one week. The preferred settings, the body postures and subjective evaluations were assessed during normal working activities of the operators. The preferred ranges disclose the following figures: keyboard height (home row above floor) 71-87 cm, screen height (centre above floor) 92-116 cm, viewing angles (eye to screen centre) + 2 to -26 degrees, visual distance (eye to screen) 61-93 cm. There was practically no correlation between preferred settings and anthropometric data of body length or eye levels above floor. The study of body postures revealed that the great majority of operators tend to lean backwards with trunk inclinations between 97 degrees and 121 degrees (95% confidence interval). Some of the preferred settings strongly differ from those recommended in many brochures and standards. The physical complaints in the neck-shoulder and back area are diminished with the preferred settings.

[Studies on an adjustable video screen work station]. / Untersuchungen eines verstellbaren Bildschirmarbeitsplatzes.

An adjustable VDT workstation was studied under practical working conditions. The preferred settings of keyboard and screen were assessed in a vertical and horizontal plane. The great majority of operators preferred a backward leaning trunk posture which was associated with a lower incidence of physical complaints.

[Ergonomic design of alpha numeric keyboards]. / Ergonomische Gestaltung von alphanumerischen Tastaturen.

Split keyboards have been developed based on laboratory and field studies. They are characterized by a large forearm/hand support, an angle between the two half keyboards of 25 degrees, a frontal-, lateral inclination of 10 degrees and a hand-conforme key arrangement. These split keyboards reduce constrained postures in arms and hands. The keyboard can be operated with supported forearms. Work on a split keyboard is more comfortable and it was preferred by a large majority of the users.

[Load factors at visual display terminals (author's transl)]. / Belastungsfaktoren an Bildschirmarbeitsplätzen.

A medical examination and questionnaire in various office workplaces (N = 295) shows that in intensive work at visual display terminals rheumatic and asthenopic disorders are very frequent. Muscle pain and eye complaints are correlated. The incidence of eye disorders and visual acuity are related to lighting conditions (local and temporal oscillation of characters on the visual display) at the individual workplaces.

[Cervicobrachial occupational diseases in office workers]. / Arbeitsbedingte cervicobrachiale Beschwerden bei Büroarbeiten.

A comparison of Japanese and Swiss studies on keyboard operators in office work shows that objective and subjective symptoms of injuries in muscles and tendons of te cervicobrachial region are frequent in both countries. It is possible to demonstrate a clear relation between workplace dimensions, postures and impairments. We agree with the Japanese view, that the localised symptoms should be considered as a syndrome of Occupational Cervicobrachial Disorder.

[Eye stress from work with visual screens]. / Augenbelastung an Bildschirmarbeitsplätzen.

Four groups of office tasks were studied: Data entry terminals, conversational terminals, traditional office work and typing. Eye impairments are observed in every group of office employees, but the impairments are more frequent in VDU operators. The impairments persist during leisure time. High luminance contrasts between screen and source document are associated with an increase of eye troubles. Increased oscillating luminance of characters is associated with lower visual acuity, with a higher incidence of subjective and objective symptoms of eye irritation including more frequent use of eye drops.

[Posture and muscular fatigue during work with a book-keeping machine]. / Körperhaltung und Muskelermüdung bei Arbeiten an Buchungsmaschinen.

A survey on localized fatigue was carried out in 119 accounting machine operators. In 51 cases the dimensions of the working places and different characteristics of the body postures were measured. The incidence of localized fatigue symptoms was found to be related to the degree of ulnar deviation of the hand, to the angle of the elbow as well as to the angle of the head inclination.

Ergonomics of posture--review of various problems of standing and sitting posture.

Medical and ergonomic field studies indicate that bad standing and sitting postures are sometimes accompanied by pains in muscle and connective tissues of tendons, joint capsules and ligaments. There is evidence that such pains can become the symptoms of chronic diseases attributed to rheumatic disorders. Recent orthopaedic research revealed that inadequate standing and sitting postures provoke excessive increases of intradiscal pressure. These orthopaedic findings, together with ergonomic investigations on sitting behaviour and somatic troubles, provide good bases for the construction of rest chairs and work seats.