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- Feng, Y., et al.
(författare)
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Effects of arm support on shoulder and arm muscle activity during sedentary work
- 1997
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Ingår i: Ergonomics. - London, United Kingdom : Taylor & Francis. - 0014-0139 .- 1366-5847. ; 40:8, s. 834-848
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate different arm supports by comparing the activity of shoulder and arm muscles during various work tasks, with and without the lower arm supported. Twelve female subjects, aged between 23 and 37 years, were asked to perform three types of tasks: typing, simulated assembly work (in two different positions), and pipetting. The supports used were: fixed arm support (FIX), horizontal movable arm support (HOR), and spring-loaded arm support (SLA). During the experiments, the electromyograms (EMG) of four muscles were simultaneously recorded: m. deltoideus anterior and lateralis, m. trapezius pars descendens and m. extensor carpi radialis brevis. Normalization was made against maximum isometric contraction. The mean values of the normalized EMG levels showed a reduced EMG level of the shoulder muscles when using arm supports in all the tasks, and for all muscles but the wrist extensor, compared to the EMG levels without arm supports. The horizontal movable support was more effective in reducing the EMG levels of the shoulder muscles than other arm supports, in tasks at table height. Thus, it is possible to reduce muscle activity of the shoulder region by using arm supports. Further research is needed to make biomechanical calculations to compare the EMG level of these muscles using suspension and the effects of inclination of work task.
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| 2. |
- Feng, Y., et al.
(författare)
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Effects of arm suspension in simulated assembly line work : muscular activity and posture angles
- 1999
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Ingår i: Applied Ergonomics. - Oxon, United Kingdom : Elsevier. - 0003-6870 .- 1872-9126. ; 30:3, s. 247-253
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Tidskriftsartikel (refereegranskat)abstract
- The electromyogram and posture angles of the shoulder and arm were recorded during sitting manipulative work in three positions, with and without the forearm suspended by a balancer. A Selspot system was used to record movements. The results from 12 female subjects (mean age 29 yr) showed that the activity in deltoideus anterior decreased significantly by using a balancer. Lower mean values were also noted for deltoideus lateralis and the trapezius muscles. The neck inclination increased with higher work area position, but was independent of the use of a balancer.
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| 3. |
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| 4. |
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| 5. |
- Oohashi, T, et al.
(författare)
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Mouse ten-m/Odz is a new family of dimeric type II transmembrane proteins expressed in many tissues
- 1999
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Ingår i: Journal of Cell Biology. - 0021-9525. ; 145:3, s. 563-577
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Tidskriftsartikel (refereegranskat)abstract
- The Drosophila gene ten-m/odz is the only pair rule gene identified to date which is not a transcription factor. In an attempt to analyze the structure and the function of ten-m/odz in mouse, we isolated four murine ten-m cDNAs which code for proteins of 2,700-2, 800 amino acids. All four proteins (Ten-m1-4) lack signal peptides at the NH2 terminus, but contain a short hydrophobic domain characteristic of transmembrane proteins, 300-400 amino acids after the NH2 terminus. About 200 amino acids COOH-terminal to this hydrophobic region are eight consecutive EGF-like domains. Cell transfection, biochemical, and electronmicroscopic studies suggest that Ten-m1 is a dimeric type II transmembrane protein. Expression of fusion proteins composed of the NH2-terminal and hydrophobic domain of ten-m1 attached to the alkaline phosphatase reporter gene resulted in membrane-associated staining of the alkaline phosphatase. Electronmicroscopic and electrophoretic analysis of a secreted form of the extracellular domain of Ten-m1 showed that Ten-m1 is a disulfide-linked dimer and that the dimerization is mediated by EGF-like modules 2 and 5 which contain an odd number of cysteines. Northern blot and immunohistochemical analyses revealed widespread expression of mouse ten-m genes, with most prominent expression in brain. All four ten-m genes can be expressed in variously spliced mRNA isoforms. The extracellular domain of Ten-m1 fused to an alkaline phosphatase reporter bound to specific regions in many tissues which were partially overlapping with the Ten-m1 immunostaining. Far Western assays and electronmicroscopy demonstrated that Ten-m1 can bind to itself.
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