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Biomedical subjects

W Rohmert

Publications and source records attributed to W Rohmert.

At least 19 recordsLinked to original sources
PubMed1992

Ergonomic research study on aircraft luggage handling.

In this study, the lifting and carrying of freight and luggage at a large German airport is classified by typical conditions of performance. These manual load handling tasks take place in height-restricted workplaces. Different methods for an ergonomic evaluation of these tasks are used. The results of the epidemiological, physiological, and biomechanical studies indicated a strain bottleneck during loading tasks in aircraft holds. Therefore, an additional laboratory study was done, in order to analyse the influence of work weight and weight of work object on heart rate, subjective RPE, and number of work objects handled. As a result of the study, the airport has developed a special lifting and carrying training for the aircraft handlers which aims to reduce strain on the postural and locomotor apparatus by an appropriate technique of work. The training programme consists of theoretical instruction by a company doctor and practical exercises under the supervision of a specially-trained sports teacher.

Accidents, Occupational↗
PubMed1990

Ergonomic evaluation of a wheelchair for transfer of disabled passengers at a large airport.

Transferring disabled passengers to the aircraft, both arriving and departing, is one passenger service at a big airport. We use different ergonomic research methods (registration of heart rate, AET job analysis as well as a standardized questionnaire) to evaluate the present wheelchair design. Due to e.g. the high wheelchair backrest, the forces needed to handle the chair and other facts, the current wheelchair causes a strain bottleneck. The results of the AET analysis and the rating of the perceived exertion confirm this finding. A redesigned wheelchair based on ergonomic principles, which reduces stress on the employees and offers more comfort to disabled passengers, is presented.

Aviation↗
PubMed1989

Effects of vibration on arm and shoulder muscles in three body postures.

The electromyographic responses of arm and shoulder muscles to vibrations were studied in three postures similar to the postures of drilling in a ceiling, drilling in a wall and drilling in a floor. This experiment was performed within the defined parameters of: vibrational frequency at 30 Hz, acceleration level 40 m.s-2 (rms), pushing force expressed as percentage maximal voluntary contraction, and gripping force which was set at 100 N. The exposure time for each test was 5 min. The general findings from these three body postures show that all the examined muscles were affected by exposure to vibration. The EMG index increased as follows: trapezius muscle 39% (p less than 0.05), lower-arm flexor muscles 23% (p less than 0.05), infraspinatus muscle 14% (p less than 0.05), lower-arm extensor muscles 14% (p less than 0.1) and biceps muscle 6% (p less than 0.1). The muscle most affected by vibration was found to be the trapezius muscle. It should be taken into consideration that vibration can be a contributing factor in neck/shoulder disorders among power handtool operators. The general conclusion from this study is that changes in working posture give different transmissions of vibration in the upper extremities. It seems as if the prime movers and muscles with an increased muscle length or increased degree of contraction are most affected by vibration.

Adult↗
PubMed1984

[Objectivity, validity and reliability of determination of recovery times following exhaustion trials in heavy dynamic muscle work from time series of heart rate].

Records of heart rate after 152 experiments with exhaustion of three male subjects were rated by three experts to determine the end of the recovery phase. Inter-rater-reliability of recovery times vary between 0.87-0.97 according to the method of calculation. An algorithm for the identification of the end of recovery is developed by approximation of the expert-ratings. The corresponding rater-reliability of the algorithm is 0.9. A stepwise multiple regression shows, that most of the variance of recovery times is explained by heart rate at the end of the working phase (63.8%) and by the conditions of the rest phase (18.9%), whereas the stress conditions in the working phase, as type (10.6%), level (20%) and duration (0%) of stressors are concerned, have less explanatory value. These results differ from the literature. The differences are discussed with respect to different criteria for "fatigue" and "recovery".

Adult↗
PubMed1983

[Development of demands with increasing technology in text processing].

Text-processing task demands are inquired about by means of an Ergonomic Job Description Questionnaire. The tasks are related to 5 steps of technologies and demands are documented for each of the technologies. With increasing technology demands on visual perception and work organisation dominate, while some demands on energetic work and environmental conditions decrease.

Computers↗
PubMed1983

[Tremor reaction to mental and emotional stress].

Reactions of tremor before and after stress were registered with a new method. Reactions with informatory-mental stress (adding tests with increasing time pressure) can only be interpreted by considering performance. Reactions with informatory-emotional stress (University examination; tasks in a central TV control room) are task specific when tremor is inter-individually normalized.

Fingers↗
PubMed1983

[Quantitative analysis of superposition of environmental task requirements].

Requirements for 1486 tasks have been registered with an Ergonomic Job Description Questionnaire (EJDQ). Frequencies of high and extremely high scaled environmental task requirements are analysed, related to branches, tasks and sex. The frequencies of superpositions are analysed for dominating requirements. Priorities for ergonomic research may be defined with the method presented.

Ergonomics↗
PubMed1983

Keyboard design through physiological strain measurements.

The physiologically tolerable range of positions for the joints of the upper extremities have been investigated for typing tasks by recording the myoelectric activities of the involved muscles. For long-term typing tasks a split keyboard is recommended allocating a key field to each hand. The fields should be rotated against each other in the horizontal plane and inclined laterally.

Journal Article↗
PubMed1982

[Ergonomic strain measurement in text processing].

Text processing task demands are analysed by using an Ergonomic Job Description Questionnaire. The tasks are classified by cluster analysis. Tasks out of each cluster are examined with respect to performance and physiological strain by 8-h measurements. These reactions are assessed in terms of tolerance limits and the distribution of demands is discussed for non-tolerable work conditions.

Female↗
PubMed1982

[An optimized filter band analyzer for quantification of localized muscle fatigue].

A filter bank analyzer is described which determines the central frequency of the electromyographic signal as a characteristic value and exhibits it continuously. In contrast with previous methods, this analyzer needs only a narrow frequency band and few filters to obtain exact quantitative results. The filter bank parameters are determined by adapting them to the amplitude spectra of electromyograms during fatiguing dynamic muscle work. Six parallel band-pass filters transmit the expected average spectral function, with minimized differences in the frequency range from 18 Hz to 140 Hz. The systematic error of the center frequency amounts to less than 0.5%, when using precision filters with high roll-off. An example compares the shift of center frequency method with the fatigue index of myoelectrical activity.

Electromyography↗