ABSTRACT
To examine the variation in the knee extension force and the integrated electromyogram from rectus femoris, medial vastus and lateral vastus muscles with the knee joint angle in growing children, measurements were conducted in 61 school boys aged from 7 to 12 years old. Anthropometric measurements were also done on the body height, the lower limb length, and so on. Results obtained were as follows.<BR>1) Ratio of the lower limb length comparing with the body height increased with the grade.<BR>2) Maximal force at each joint angle in each grade was shifted peak from 70°to 90°with the grade.<BR>3) The pattern of the integrated surface electromyogram from rectus femoris, medial vastus or lateral vastus muscle at each joint angle was the same in all of the grade. The integrated electromyogram at the maximal voluntary contraction was maximal at 45°of the knee joint angle in the rectus femoris muscle, at 110°in the medial vastus and at 90°in the lateral vastus muscle.
ABSTRACT
In order to examine the personal space perception, measurements were conducted on both elbows in 14 men and 46 women. Each subject, with his (or her) eyes closed and with his upper arm fixed horizontally, was instructed to stop the vertical and horizontal swing motion of his lower arm at the point he considered to be the middle of the range of possible motion on the front and side of plane at his shoulder, and this was repeated ten times. In various conditions, similar measurements were also done to study factors affecting the personal space perception in 14 men.<BR>Mean values of bisected angles in percentage against range of motion were deviated from the middle points in the direction of the elbow extension, although there were large differences between the individuals. The deviation was smallest in the vertical. side of plane, and was larger in the horizontal plane than that in the vertical plane. The deviation was not so much affected by the various conditions.<BR>It was suggested that the gain of the personal space perception is higher in the elbow extension than in the elbow flexion and its difference is larger in the horizontal plane than in vertical plane of the human elbow joint.
ABSTRACT
To examine the personal space perception, measurements were conducted on both arms in 227 young men and women. Each subject, with his eyes closed, was instructed to stop the horizontal swing motion of his arm at the point he considered to be the middle of the range of possible motion on the horizontal plane, and this was repeated ten times.<BR>Mean values of bisected angles were deviated from the middle points in the direction of the horizontal adduction, although there were large differences between the individuals. The deviation was larger in the right arms than that in the left, and it increased with the increasing range of motion of the horizontal abduction.<BR>It was suggested that the gain of the personal space perception is higher in front of the body than in the side on the horizontal plane of the human shoulder.
ABSTRACT
Intragastric pressure at gastric empty state was measured by radio capsule method during various exercises in three human subjects. The E. I. L. Type. 70. pressure sensitive radio capsule of England make was used in this experiment.<BR>1) The empty intragastric pressure at rest was 30.0-33.0 cmH<SUB>2</SUB>O and the gastric peristalsis was 2-3 sec. in frequency and less than 3 cmH<SUB>2</SUB>O in amplitude.<BR>2) The resting gastric peristalsis was disappeared immediately after the onset of deep respiration or exercise. The pressure raised to maximum 76.0 cmH<SUB>2</SUB>O at the end of deep abdominal inspiration.<BR>3) The intragastric temperature raised during various exercises and increasing grade was showed in Table of the text.
ABSTRACT
Heart rate and R-R intervals of ECG during sleep were examined in healthy young men. Heart rate per minute were gradually decreased when the subject fell asleep. Whole through one night sleep data there were two typical heart rate variation patterns, namely stable stage and fluctuating stage. Sleep stages determined by EEG, EOG and EMG of chin corresponded with these two patterns; slow wave stage (Stage III/IV) showed the stable pattern, REM Stage and Stage I showed the fluctuating pattern, Stage II both patterns. The fluctuating pattern showed higher heart rate level.<BR>Further studies computed R-R intervals and its variations of ECG revealed 4 typical patterns on the variations, and well corresponded with sleep patterns determined by the above methods. R-R interval varied from 1.39 to 0.67 sec during sleep. R-R interval variation befor onset of sleep showed lightly rythmical periodicity (20-40 sec) and small fluctuation (0.1 sec) (awaking pattern) . R-R intervals after onset of sleep extended gradually, fluctuating midly (0.1 sec) and did not show any periodicity (transient pattern) . R-R interval reached its maximum level then. At slow wave stage (S-III/IV) R-R interval showed mild fluctuation as the transient strage, and did not show any periodicity (stable pattern) . At REM stage and S-I it showed large fluctuation (more than 0.2 sec) and significant periodicity (10-30 sec) . At S-2 if the stage was in the course of deepening the sleep, it showed stable pattern and if it was in the course of lightening the sleep it showed fluctuating pattern.
ABSTRACT
In this study, the relationships between the contractile properties of human motor units and their discharge patterns, characteristics of recruitment and others were examined. Action potentials of single human motor units in<I> m, extensor digiterum</I>were detected by use of an inserted electrode. Tension curves of single motor units were recorded under the conditions that tension in finger extension was gradually increased, and that the subject relaxed his muscle as soon as he observed a sweep on a Braun tube triggered by the action potential of a single motor unit. About 100 twitch tension curves were summed up to obtain the average tension curve of a single motor unit. The τ-S diagrams were obtained from the mean discharge intervals (τ) of motor units at various sustained tensions and their standard deviations (S) . The λ values were also obtained from the relation F<SUB>th</SUB> (-T<SUB>1</SUB>G) =ρG<SUP>λ</SUP>.<BR>It was observed that the contraction time of the twitch tension curve of single human motor unit in a muscle was nearly proportional to τs (the τ values at a constant S value) . We presume that the regularity of discharging of motor unit affects the contraction speed in human muscle, because the motor unit with more regular discharging has longer contraction time of twitch.
ABSTRACT
It had been proposed by Kurata that relative threshold value F<SUB>th</SUB> of single motor units depends on the gradient G (kg/sec) of the tension increase of muscle in such a manner as<BR>F<SUB>th</SUB> (≡T.G) =ρG<SUP>λ</SUP><BR>Here T<SUB>1</SUB> is the time interval from the onset of EMG to the moment of recruitment of a motor unit and ρ is a proportional constant. The motor unit with a <I>positive/negative</I> value of λ is characterized to be <I>static/phasic</I>.<BR>Morimoto and Hasegawa reported that the above relation also holds for the relaxation period, provided that Ftn and G are replaced by the tension at the moment of silence and the absolute value of G, respectively. In this case, the motor unit with a <I>positive/ negative</I> value of λ is characterized to be <I>phasic/static</I>.<BR>In order to investigate the characteristics of motor units during relaxation period under the influence of pre-relaxation states, such as the increase of tension up to 4kg at the gradient of 0.5kg/sec and the state sustained at 4.0kg for 30sec. Single motor units of <I>m, vastus medialis</I> were studied by the same method as that of Morimoto and Hasegawa.<BR>The following results were obtained;<BR>1) Both at contraction and relaxation periods, the above relation was confirmed.<BR>2) The motor unit with characteristics of recruitment modes was influenced by the pre-relaxation state, but its tendency was not definite. These results suggest that <I>phasic/static</I> characteristics of motor units are not stationary but fluctuate depending on the pre-relaxation states.