The present experiments were performed to investigate changes of EMG reaction time with upperarm muscles. The reaction time in electromyogram of the elbow flexor (EMG-Reaction Time) was measured during quick isometric contractions with maintaining muscle force (the fraction of maximal voluntary contraction, MVC). Subjects, responding to audio stimulus (AS) and turning on electricity on skin stmulus (SS) presented about 2 sec to 4 sec after a verbal warning, and then responding his biceps brachii muscle as fast as possible in following contractive conditions : 0%MVC, 20%MVC, 40%MVC, 60%MVC and 80%MVC. Mean EMG-RTS were calculated from 10 to 20 trials. Compared to 60%MVC condition, EMG-RTS of 0% MVC were longer in both stimulus conditions. EMG-RTs and fractions of %MVC were correlated significant inverse between both AS and SS conditions. On the other hand, RT of SS condition was shown to be particularly shorter than that of AS condition with increasing % MVC. The EMG-RT should be influenced by the increase of muscle activities according to % MVC. Therfore, these results suggest that the motor cortex and/or other central location and the motoneuron pools may be excited due to enhancement of peripheral somatosentory activities.

抄録全体を表示

This research was conducted with the purpose of comparing the clothing of adult males by dividing the subjects into a student group and a father group. The subjects for the survey were male students of Tokyo Gakugei University (18-20 years of age), and their fathers (44-57 years of age). The occupation of the father was limited to the wage-eamer only. The survey was conducted in the middle of each month during the period from May 1981 to January 1982. From the results of the survey, the following conclusions were obtained : l. The total weight of the clothing decreased from the spring to the summer, while it increased from the autumn to the winter. Although the weight of the upper garment varied by the season, no variation of the weight of the lower garment due to the season was noted. 2. A high correlation was observed between the environmental temperature and the weight of the clothing. 3. Among the various kinds of clothing, underpants had the highest difference of wear rates between the student group and the father group. The wear rate of underpants by the fathers was high, whereas by the students was low. The students seldom wore underpants. 4. As a whole both groups wore short coats and short sleeve with the neck open during the summer. 5. For trousers, the students preferred to wear jeans throughout the year. 6. The wear patterns of the males by the season were considerably uniform as compared with those of females.

抄録全体を表示

Colored thermograpy was used to observe skin temperature distribution over the upper half of body during bicycle exercise in cool environment. Skin temperature began to fall immediately at the onset of exercise. Increased work loads produced a proportional reduction in skin temperature.

抄録全体を表示

We have developed a method that estimated breath-by-breath alveolar gas exchange by a compensation for changes in lung gas stores in studying respiratory transients during exercise. Inspiratory and expiratory flow signals were recorded with separate pneumotachographs. CO₂ and O₂ gas fractions were measured at the mouth continuously. A data acquisition program consisted of A/D conversion of the respiratory signals and calculation of alveolar gas exchange variables. The correction for breath-by-breath changes in lung gas stores was applied to the total gas exchange which was obtained by subtracting expired from inspired gas volume. Incomplete or abnormal breath-by-breath dada were automatically inspected and edited either by combining with the previous or following incomplete companion breaths. The breath-by-breath variation in the gas exchange at the mouth was larger than the alveolar gas exchange, particularly in the transient state. The variation was attributed to the invalidity of the steady state gas uptake equations which assumed constant end-expiratory lung volume over a single respiratory cycle. However, during the steady state, the gas exchange at the mouth averaged to the same value as the alveolar gas exchange. The breath-by-breath analysis of alveolar gas exchange enables the investigator to study the transient and non -steady state responses to exercise.

抄録全体を表示