The data obtained from 106 7th grade boys and 224 8th grade boys were analyzed in terms of the inter-relationships among the results of various test items. The conclusions obtained from the analysis were summarized as follow :
1) No difference associated with the grade level was observed in the performances of side-step test, and chinning.
2) The group classified as heavy group in term of the body weight demonstrated a superior performances in dash shorter than 400 meters, whe reas the group classified as light-weight group did better in distance run of 1500 meters and 2000 meters.
3) The performances in distance-run longer than 1500 meters correlated higher with the performances in 100-meter dash rather than the scores of step test or the measures of lung capacity.
4) The negative correlation between the distance of broad jump and the time of 25-meter dash was higher in 8th grade boys than it was in 7th grade boys than it was in 7th grade boys.
5) For the 8th grade boys, the group 50-55 kg of body weight performed best in back strength and vertical jump, whereas the group 45-50 kg. body weight perfo-rmed best in chinning and elbow flexion strength. In these tests, the said two grou-ps ranked at the peak, and the performances decrease in both directions of larger and smaller body weight.

Electrocardiographic studies were made on 676 excellent, well-trained atheletes.
The values of voltage and interval of each deflection were compared with normal value for the Japanese reported by Ueda et al. and were analysed statistically.
The results obtained were as follows:
1) R-R intervals were longer in atheletes than in untrained controls. Sinus bradycardia was markedly observed in atheletes in their twenties.
2) P-Q interval showed no difference between the atheletes and controls in a younger than twenty years group while that was more increased in the former than the latter in an older than 20 years group. Abnormal P-Q prolongation i. e. over 0.2 sec. was more frequent in excellent atheletes than non-excellent atheletes in a younger than 20 years group.
3) QTc (corrected QT, measured QT/√R-R) proved considerably large in atheletes especially those of a 15-19 year old group.
4) There was observed a trend of delay of the ventricular activation time (V. A. T.) in the right precordial lead, but no delay in the left precordial lead.
5) The duration of P-deflection showed a trend of enlargement in an older than 20 years group unlike in a younger group. The duration of P-deflection increased generally as age advanced. The same trend was also observed for P/PQ segment (Macruz' index) .
These findings might suggest the presence of left atrial enlargement, but they revealed neither left axis deviation in frontal plane nor mitral configuration of the P wave. They constituted a difficult problem explain.
6) R-deflection in the left precordial lead generally showed high voltage and especially in a younger group. In many of the atheletes studied SV₁ + RV₅ and RV₅ corresponded to Sokolow & Lyon's criteria for left ventricular hypertrophy (SV₁ + RV₅≥35mm, RV₅≥26mm), but those atheletes were without left axis deviation in frontal plane. In many of the atheletes R-deflection in the right precordial lead showed high voltage with a considerably correspondence to Sokolow & Lyon's criteria for right ventricular hypertrophy (R/S V₁>1. 0, RV₁≥7mm), and these atheletes revealed delayed V. A. T. in the right precordial lead.
The physiological right bundle branch block (Reindell) was also commonly observed, thus there was suggested the presence of right ventricular hypertrophy or overloading, but no right axis deviation was encountered.
It was assumed that a hard training might effect the right ventricle if not prod-uced a pathological ventricular hypertrophy
7) Atheletes in their twenties and thirties showed high voltage in T-deflection especially in V5, but they revealed almost the same T/R ratio as controls.
8) Abnormal ECG findings wree higher in an excellent group than a non-exce-llent group or an under-trained group.

In order to invesigate the changes in volitional muscular strength associated to the human growth, the five repetitive measures of maximal grip strength and the abilities of lifting the barbells in “curl” and “press” were examined.
1) Considerable differences associated to sex and age were observed in the decrement rate of the repeated grip strength. As the greatest rate of decrement was recorded for the ages from 14 to 23 years, it was considered that this decrement was due to the variation in the integrating mechanism of the contractile forces involving the nervous system or the fatigue of this mechanism, rather than the fatigue of the muscle itself.
2) The difference in ability of “press” between the two sexes became greater in accrodance with the advance in age. However, the improvement in the ability showed a linear increment both for the boys and girls, and there observed no particular stage in the course of development.
3) Up until age of 10 years, there was no difference in the ability of “curl”, which is associated to the sex, and the increment was linear. After the age of 11 years, the increment was accelerated both for the boys and girls. The ability in “curl” approached to that of “press” in boys, whereas, the ability in “curl” in the case of the girls exeeded that of “press.” The static muscular strength of the girls seemed to be considerably greater than the level assumed by the popular belief.
4) From the observations of the upper arm position in the “press” motion, the muscular development seemed to proceed from the trunk to the extremities. In this connection, the age around 8 or 9 years can be regarded as the period during which the muscular development is completed in some extent.
5) Among the boys younger than the age of 10 years, a great number of the boys failed to maintain their elbows at the right angle for a period of 5 seconds, after they “curl” the weight in the position. It was speculated that the balance between the “active” strength and the “passive” strength in muscles is established some time around the age of 10 years.

A certain inhibitory effect upon the function of deep sensory mechanism of the muscle seems to be associated with the improvement of muscular strength resulted from an intensive training. At the basic weight around 1.0-3.5kg., a trained person shows : (1) a decrement in the ability of identifying different weights held in both hands ; and (2) a decrement in the ability of gradgin the half-way strength of the maximum grip strength. Even after the repeated five trials, these subjects could not approach the half-way strength in their self-grading muscular strength.
When the maximum exertion was repeated five times in the measures of grip strength or leg extension, the performance in the fifth trial is usually considerably worse than that in the first trial. This decrement rate varies considerably in accordance with the difference in the training method. As the mechanism of muscular exertion is habituated to labor, the decrement rate becomes smaller. In this measurement, the muscular ability in single maximum exertion is the concern ranther than the fatigue of the muscle.
The contact dimension of the foot to the ground decreases with the movement of the lower legs. By measuring this dimension, the amount of the milking action in the muscles may be estimated. There is no correlation between the amount of the milking action and the muscular strength in the static contraction.

High ranking Japanese weightlifters in Tokyo Olympics and high ranking adults and high school students in the 20th Japan National Athletic Meeting were chosen for the subjects. We made research about them for many patterns of movements of the Olympic three lifts which seemed to be the most reasonable way in analyzing the movements of the lifters, by comparing the results which were gotten by the 16 mm 64 frames side filming method with their official records and lifting marks. This led to the following conclusion :
1) At the begining of the clean, dead-lift, for the press the excellent lifters accelerate the bar at a higher speed, but the increase of speed after the begining is not so much. The Olympic lifters pull up the bar bending more forward, at a knee level. But excessive forword bending makes many lifters fail to clean weell.
2) Exellent lifters bigin pressing at a high speed by vigorous extension of their body, Less-trained lifters can not use vigorous extension of their body because of presing forward, or comming down the bar again, and bending the kenee joints.
3) In the snatch excellent lifters pull up the bar at a higber speed to the knees, but they at a speed of lower acceleration from the knees. Even if they are excellent lifters, they often fail to snach in the case of pulling with over-acceleration at that point. It is inportant also in the snatch to use effectively the power of lower ports of the body.
4) It is evident from the loci of the bar that, if the bar travells upward vertically, or near vertically, squat-style lifters need to jump back properly In the case they do not jump back the for moves back and forth excessively, many lifters fail to snatch if they jump back too much.
5) In the clean for the jerk an increasing acceleration in dead lift phase during clean is necessary to become a successful lifter. It is necessary to concentrate the power of the lower parts of the body as much as possible to accelerate on the bar to a knee level. From the knee level exce lent lifters pull the bar by using the pulling power of shoulders more aectively. The barbell falling down from the dead point must be held moderately not to fall down at a high speed.
6) If lifters overstrain the shoulder muscle groups and arms at the starting of the jerk and can not dip their body well in accordance weith dropp ing movement of the bar, they will fail to jerk.
7) The dropping speed of the bar at the first step of the jerk must be marked more carefully at the second phase than at the first phase. Many who make it increase more at the second phase will fail to jerk.
8) The bar of the excellent jerker goes up with very high speed at the begining. But of the speed of the bar after that there is no diffrence between lifters.

In grip strength a subject being ordered to show one-third, one-second and twothird of his own maximum value after checking his maximum, the value he shows is not always the same as the ordered value. The Discrepancy Index was determined by the grade of the difference between the ordered value mentioned above and the value showed actually.
For 2117 subjects composed of both sexes our experiment was performed.
1) The possibility of training effect for one-third and two-third of their own maximum value existed but little for one-second.
2) Up to 16 years of age the training effect increased with their physical development, but after 17 years remarkable change of their grading ability was not found.
3) There existed no relation between the experimental results of one-third value and two-third, between the left hands and the right, and between the Discrepancy Index of pre-training and post-training.
4) The larger maximum value of grip strength became, the smaller the Discrepancy Index was. Sometimes in the individuals who have larger maximum value, the more training effect was recognized.
5) The champions of weight-lifting, Kendo and volleyball showed better results than those of the control groups.

In this report the roentgenograms of the corpus vertebrae, the disci intervertebrales of those having the good flexibility and poor flexibility were observed. Particularly the actions of the connected muscles, when the maximum trunk-flexion and extension were taken, were compared between two groups, and the factors that were supposed to have produced the difference of the trunk flexibility between the individuals were discussed.
Results are in summary as follows ;
The shrinking and extension appear in the disci intervertebrales when the maximum flexion and extension were taken. For the trunk flexion in then rear side of the disci intervertebrales, for the trunke xtension in the front side, for the left side-ward bend in the right side, and for the right side-ward bend in the left side of one, that is, in the extension of the disci intervertebrales at the opposite side to bending the differences were observed. Moreover they were appeared in the disci intervertebrales of the vertebrae lumbales remarkably, and in the group of poor flexibillty the extension of the disci intervertebrales was appeared less than in the group of good flexibility.

With 22 patients hospitalized in the Rehabilitation Center of Okayama Prefecture the oxygen metabolism of physical hanlicapped was investigated. These subjects were composed of 8 cases of poliomyelitis, 4 cases of cerbral palsy and others. The results are briefly summarized in the following :
1. In general the basic metabolism is at the lower limit of the normal level.
2. Generally speaking, the relative metabolic rate (RMR) is high in the gait of those handicapped with lower extremeties, and this is especially so in cerbral palsy.
3. The reason of a markedly low RMR in poliomyelitis when using the affected limbs for work lies in the fact that the patient is not working diligently.
4. The labor index (RMR × minutes) per day proved to be 400-1, 300.
5. The total calory consumption per day was between 1, 100 and 2, 400 Calories, and in the four cases whose calory consumption exceeded over 2, 200 Calories of the diet given, they were supplementing themselves with the food of their own choice.

The purpose of this study is to inquire histologically when red muscle fibers and white muscle fibers are differenciated and how they develope, considering from sex difference.
Wistar-strain rats of the same venter were used in this experiment. The animals of both sexes were killed at the interval of five days, from birth to 25 days. Two groups of male and female rats of 70 days old after birth were used as control groups.
M. tibialis ant. was removed and then fixed in 10% formalin for approximately two weeks. As staining, alchohol solution of Sudan black B was used.
The results are as follows :
1) Sex difference in rats' body weight was started to appear about 15 days after birth.
2) Differentiation of red muscle fibers and white muscle fibers in M. tibialis ant. was recognized about 15 days after birth in male and female rats.
3) The entire area of cross section of M. tibialis ant. is increasing during the development of rats' body as a whole. No apparent tendency on sex difference was found till 25 days after birth. On 70 days after birth the entire area of cross section in male has about 1.5 times the size of female.
4) No increase of number in M. tibialis ant. was recognized during the development of rats' body as a whole and no sex difference in number of muscle fibers.
5) The area of cross section per fiber and the average diameter of fibers are increasing during the growth of rats' body. No sex difference of those in red and white muscle fibers was found till 25 days after birth but, on 70 days after birth, it became clear. The rate of hypertrophy of white muscle fibers is greater than that of red muscle fibers.
6) Ratio of the entire area of muscle fibers to the intercelluler space in M. tibi-alis ant. is increasing during the development of rats' body.
7) No difference of area of cross section per fiber in peripheral and innermost regions was found till about 15 days after birth. On 70 days after birth the red muscle fibers in peripheral have 1.4 times the size of those in innermost, and the white muscle fibers 1.3 times.

It is supposed that, through considering the former results comprehensively, for promoting the flexibility, it is important to make the unfoldness of the extension sides of the disci intervertebrales large, and also it is needed to develop the muscular strength and the elasticity of extensor-muscle. Then, taking these factors into account, the gymnastic training that the author designed was given to the subjects. And the experimental study was tried to test whether such training develops the flexibility or not.
A. Statistical results ;
1. By giving the gymnastic training every day for about more than two weeks, the flexibility (trunk flexion, extension, side-ward bend) are developed.that is;
a. The amount of development of flexibility in the traine1 group was significant statistically but not significant in the control group, at significance level 0.05.
b. The mean of the trained group after training for two weeks was higher than that of the control group. The difference between the two means were significant statistically at significance level 0.05
c. In the trained group after training all the subjects have showed the development of flexibility but only 40% of subjects showed its development in the control group.
B. Electromyographical results ;
a. The electromyographic discharge of post-training has showed more increase remarkably than the EMG of pre-training. Furthermore, it was observed powerful and thick
b. In the EMG of post-training, the joining of new secondary movers and the pause of the antagonist discharge were come out. And then the coordination among the connected muscles for flexibility and the intensification of function of the connected muscles were observed in the EMG after the gymnastic training.