Mental fatigue : a comprehensive exposition of the nature of mental fatigue, of the methods of its measurement and of their results, with special reference to the problems of instruction / by Max Offner ; translated from the German by Guy Montrose Whipple.
- Offner, Max, 1864-1932.
- Date:
- 1911
Licence: In copyright
Credit: Mental fatigue : a comprehensive exposition of the nature of mental fatigue, of the methods of its measurement and of their results, with special reference to the problems of instruction / by Max Offner ; translated from the German by Guy Montrose Whipple. Source: Wellcome Collection.
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![THE PHYSIOLOGICAL METHODS The dynamometer. The decrease of muscular force, more exactly, of “the work that can be done by the muscle under voluntary contraction” (Eulen- berg, 601), is a purely physiological Symptom not only of bodily, bnt also of mental fatigue, as we have already skown. J. Loeb (1886) seems to have been the first to investigate “muscular activity as a meas- ure of mental activity.” Soon afterwards (1890) A. Mosso published bis studies, “üeher die Gesetze der Ermüdung [“On the Laws of Fatigue”], and his well-known book, “La Fatica” (1891), translated into German in 1892 [and into English, “Fatigue,” 1904]. Up to that time the Collin dynamometer had been used for measuring muscular strength. This instrument consists of a steel oval, wliich, when gripped with the hand, indicates by a pointer the pressure in kilograms exerted by the hand. Ul- mann’s dynamometer is another form that can be used either for measuring pressure or traction. These measurements that are secured by the use of dynamometers possess, however, little accuracy, in especial because the subjects are by no means apt to exert in an equal degree all the muscles concerned, so that when fatigue arises they may easily shift the groups of muscles and introduce into the later meas- urements groups of muscles that had relatively little](https://iiif.wellcomecollection.org/image/b28129106_0035.jp2/full/800%2C/0/default.jpg)
