To investigate the neuro-muscular coordination of the Kendo Champions, we measured the tensions of blow with a wooden sword, bamboo sword and a split bamboo on the occasion of Menblow and hard blow (Suemonogiri) . Simultaneously we recorded the EMG of M. biceps brachii and triceps brachii of both arms, then the time elapsed between the starting of the motion of two limbs, each other four limbs, when subject felt to start them synchronusly. Our results are in the following. 1) The well trained Kendo Champion makes a blow by useing of M. triceps brachii more effectively, and at this moment M. biceps brachii is relaxed, after several repetitions, the same pattern of those EMG are obtained. On the contrary, the untrained subjects are tend to blow by using of M. triceps brachii uneffectively, at this moment biceps brachii is contracted very often and the different patterns of EMG are obtained as they act the same repetitive motions. 2) The difference of the blow energy between the well trained Kendo Champions and untrained subjects is larger than the difference between the tension of them. 3) In measurement of the time elapsed between the starting of the motion of two limbs, we couldn't succeeded to find the significant difference between the well trained and untrained group.
The effects of the inner diameter of respiratory valve on the pulmonary ventilation and oxygen uptake were studyed. Five healthy male subjects were asked to run on a treadmill with 8.6% slope. Each subject equiped a respiratory valve with five kinds of diameter (19mm, 24mm, 30mm, 34mm and two valves of 19mm) performed all-out running at a given speed at which he could run about 6 minutes. In all experiments, the inner diameter of the connective tubes in valve, stop cock and bag were 30mm. From the experiment, following results were obtained ; up to diameter of 30mm the larger the diameter of valve, the higher became the pulmonaly ventilation, accompanied with the increasing oxygen uptake. However, a large diameter of 34 mm did not produce further increase in ventilation. The difference in ventilation between 19mm and 30mm was found in such an intensive work that demanded over 5011/min. of ventilation and it increased related to the increment of work intensity. It is concluded that in studying the respiratory function during severe work, it is better to use respiratory valve as large as 30mm in diameter.
In order to compare the work efficiency in hypoxia with that in normal environment, given work was loaded to five healthy male subjects in a decompression chamber. Hyoxia was induced by decompression to a simulated altitude of 4, 000 meter, where the subjects walked on a treadmill with a slope of 5% at a speed of 80 m/min for 10 minutes. Oxygen consumption, expiratory volume, R. Q., respiratory rate, heart rate, oxygen pulse, and oxygen removal were measured before, during and after the work. Blood samples were taken to determine lactate value before and after the work. The results obtained and the conclusion are as follows ; 1) Vo2 at rest in the hypoxia was slightly less than that of the control, while the total oxygen consumed by the work was more in the hypoxia than the control value. 2) Making correction for anaerobic mechanism, effect of respiratory and circulatory acceleration, and decreased air density on oxygen consumption revieled that the true work efficiency in hypoxia was completely same as in the controle. 3) Respiratory quotient dropped in the early stage of the work, thereafter increased in the control, while it increased on work without initial drop in the hypoxia. Total extra CO2 eliminated by the work was significantly more than the control value.