ABSTRACT
The purpose of this study was to investigate the controllability of several pursuit movements of the arm muscles. Three subjects in a sitting position were studied for elbow flextion and extension. Three wave forms (sinusoidal, sawtooth and rectangular) on VDT were followed by the subjects, and 5 work loads were given at 0.3 Hz frequency.<BR>The following results were obtained.<BR>1. There was phasic delay in the order: sinusoidal (-10°), sawtooth (-15°), rectangular (-20°) .<BR>2. An overshoot phenomenon was observed for each wave form during the flexion phase at a work load under 10% of the maximum strength. At a work load of over 10% of the maximum strength, an undeshoot phenomenon was observed.<BR>3. With regrd to controllability, the error area increased in the order: sinusoidal (4-7%), sawtooth (6-12%), rectangular (15-25%) .<BR>4. There was a significantly smaller EMG output from antagonists during both the flexion and extension phases at workloads of 4 and 8 kg.
ABSTRACT
The purpose of this study was to clarify compensating element of motor control system on the leg, and to analyze the effect of the variation in various loads on pursuit movement in the exercise of flexion and extension of the leg. The subjects for this study were sixteen healthy males, from 22 years of to 64.<BR>As the means of the experiment, the pursuit movement of the leg was used and the sitting position was applied.<BR>The experiment conditions were dicided to sinu waves of 0.4 Hz of exercise rhythm and 1, 2, 4, and 8kg loads attached on the leg.<BR>The following results were obtaind.<BR>1. About amplitude ratio of pursuit movement, the optimal control was young ages (22-29 years) of extension, but middle and high ages were shown lower than command amplitude. When leg is flexed, the pursuit amplitude of all subjects were larger than command amplitude.<BR>2. About exercise rhythm, both flexion and extension, young ages were shown about 5-10 degree slower than that of command wave, but middle and high ages were shown both slow and quick on -15-20 degree.<BR>3. About error of between command and response waves, both young and middle ages were shown about 5-15cm<SUP>2</SUP>. The high ages were shown a value two times as much young and middle ages.
ABSTRACT
The purpose of this study is to clarify the characteristics of the short-term motor-memory and to analyze various loads effect of motor-retention in the exercise of flexion and extension of the fore-arm. As the means of analysis, correlation function between command and response waves was used efficiently and furthermore the electric computer system helped to investigate motor-retention. Many experimental conditions were decided to 0.1-0.8 Hz of one's exercise rhythm, 0-0.5 kg of loads attached to the fore-arm, and 3-6 cm of exercise displacement. Three healthy persons were employed as subjects.<BR>As the results of this study, following points were shown clearly.<BR>(1) After the fore-arm was exercised to the flexuous and extensional directions for 25 sec., response waves of motor-retention were recorded to Data-recorders for 60 sec Quantitative analysis of this motor-retention became effective by using the method of correlation function.<BR>(2) About exercise rhythm (frequency), the rapidity of fore-arm exercises in the retentive learning was 0.05 Hz slower than that of these exercises in the begining learning.<BR>(3) About the transfer gain of these exercises between command and response waves, two motor-gains of the retentive and begining learning were shown the same values only when these exercises were practised at experimental conditions of 0.8 Hz frequency and 0.5 kg load.<BR>(4) Motor-retention rate, that was calculated from error values of performance, was dropped down such as about 0.3 rate in proportion to the time elapsed of recollection and also to rhythm-slownes of the command frequency.<BR>(5) Optimal exercise displacement of the fore-arm was proved to the median of 6 and 3 cm in order to reappear the length memorized by the begining learning.<BR>(6) Discharged voltages of the integrated EMG in Flexor and Extensor C arpi Radialis were recorded lower at the time, when motor-retention was displayed rightly and exactly.<BR>(7) Sychological reminiscence and this motor-retention were shown quite opposite results in the learning points of reaction time, rhythm, strength and displacement, because the former was dependent upon the memory in the central nervous system (brain cortex), while the latter relied upon the memory in the peripheral-nervous system (receptor) .
ABSTRACT
Analytical method of correlation function and Fourier transformation has been applied for surface electromyogram. This study is to be aimed to investigate relation between motor-activities in isotonic muscular contractions and frequency in muscular electric discharge. By help of digital electrical computer, frequency characteristics in isotonic contraction of M. Biceps Brachii and M. Rectus Femoris have been calculated as Power Spectrum Density clearly and quantitatively.<BR>As the result of this study, following points were revealed.<BR>1) Fourier transformation was cleared up as the available method of physical fitness research in interpretation of surface electromyogram, on the assumption whose phenome-non was stationary in the process of statistical probability.<BR>2) Upon isotonic contraction, high and low frequency bands were divided distinctly among muscular discharge of surface electromyogram, that were about 20Hz and 75-90 Hz bands.<BR>3) In proportion to intensities of load and to alteration of movement velocity, high discharge frequency band showed changes of ranges of ±15Hz, but low discharge frequency band showed no change.<BR>4) In high discharge frequency band, density of Power Spectrum of M. Biceps Brachii was larger than that of M. Rectus Femoris, but on the other hand of low dis-charge frequency band, this Power Spectrum displayed no difference between both muscles.<BR>5) Comparing with two sorts of muscular contraction, that were isotonic and isometric, high discharge frequency band of the former was higher about 10Hz than that of the later.<BR>6) It was supposed that this low frequency band was dependent upon tonic Neuro Muscular Units and was corresponding to slow contraction of red-colored muscles.<BR>7) It was considered that this high frequency band depended on phasic N.M.U. and had connection with quick contraction of pale-colored muscles.
ABSTRACT
Analyses of correlation function and Fourier transformation are one of the important tools in the investigation of biological phenomena. Since the method of these analyses had been applied for interpretation of surface electromyogram, isometric muscular contractions had been estimated easily and accurately. Reliability and validity of measured values had been acquired by the assistance of the electro-computer and statistology. On the assumption that generated processes of surface electromyogram of arm and leg were 1) probabilistic 2) stationary and 3) Gaussian, power spectrums of probability density functions of measured values, were calculated in X-Y charts.<BR>As the results of the expeliment, following points were revealed.<BR>1. For the estimation of surface electromyogram upon muscular isometric contractions, these analytical methods should be applied for physical fitness researches with reliability and validity of the results.<BR>2. Upon the isometric muscular contraction, main discharge-frequency among surface electromyogram were existed in two bands of about 20 Hz and 90 Hz peaks.<BR>3. In proportion to intensities of load (Kg), magnitude of the agonist's discharge was increased in the frequency-band of 90 Hz, and that of the antagonist's discharge also was increased in the frequency-band of 20 Hz.<BR>4. According to these results, it was assumed that frequency-band of about 20 Hz would be corresponded with tonic muscular discharge and that of about 90 Hz would be equivalent to phasic muscular discharge.<BR>5. The longer time of muscular contractions sustained, the wider the frequency-band of about 90 Hz became on account of mixed and interfered discharges of neighboring muscle groups.