[Studies on physiological changes due to prolonged standing posture (author's transl)].
In relation to static work, an experiment has been made with intention to examine the influence of maintaining standing posture for a long time on human body. The results are as follows: 1) Fluctuation waves of the body weight were classified into two types: type A, a higher amplitude with slow waves, and type B, a lower amplitude with rapid waves. 2) Spectrum analysis on the fluctuation waves of the body weight indicated that type A showed a gradual lowering in relative power in proportion to the wave frequency with the lapse of time, but type B showed a peak in power at around 10 Hz and it increased with the lapse ot time. 3) Action potentials from the left and right gastrocnemium muscles decreased almost simultaneously with the lapse of time in type A with a significant correlation between the left and right, while in type B there was no certain relation between the left and right as well as with the lapse of time. 4) The body weight tended to concentrate on the heel of the dominant foot with the lapse of time. 5) The brain alpha waves increased with the lapse of time, accompanying with a periodical change. 6) In the relationship between the brain alpha waves and the action potential from the gastrocnemius muscle, there was the same cycle at about 1.5 Hz and no change was seen with the lapse of time. 7) There was no significant change in the function of maintaining concentration (TAF). These results suggest that: 1) Besides the reflex mechanism existed as physiological tremor through the stretch reflex loop in maintaining a standing posture, there is a regulation mechanism working to keep balance of the body through the visual organ. 2) The standing posture itself is not always a big stress factor to human body. 3) On the stress by monotonous work, it is necessary to analyse the physiological and psychological load on human body.
D000293:Adolescent; D000328:Adult; D001288:Attention; D001835:Body Weight; D004569:Electroencephalography; D004576:Electromyography; D006801:Humans; D008297:Male; D010507:Periodicity; D011187:Posture; D013997:Time Factors; D014937:Work