Tetsuo Katsuura
Biographic Data
| ID | 4292227 |
|---|---|
| NAME | Tetsuo Katsuura |
| GIVEN NAMES | Tetsuo |
| FAMILY NAME | Katsuura |
| SIGNATURE | KATSUURA T |
| AFFILIATIONS | Chiba University |
| ORCID | 0000-0002-7105-0887 |
| VERIFIED | Yes |
| TOTAL WORKS | 32 |
| TOTAL CITATIONS | 12 |
| WORKS AS AUTHOR | 32 |
| WORKS AS EDITOR | 0 |
| FIRST PUBLICATION YEAR | 1975 |
| LATEST PUBLICATION YEAR | 2020 |
| H-INDEX | 2 |
What is the significance of the traditional pinching mode of holding chopsticks
Background The purpose of this study was to clarify the influence of manipulation mode of chopsticks on the learning process, using assessment of task performance and electromyography, and to understand the significance of the traditional manipulation mode from the viewpoint of physiological anthropology. Previous studies have described two modes of manipulating chopsticks, the traditional pincers-pinching mode and the scissors-pinching mode. Met…
The core interthreshold zone during exposure to red and blue light
BACKGROUND: This study tested the hypothesis that the core interthreshold zone (CIZ) changes during exposure to red or blue light via the non-visual pathway, because it is known that light intensity affects the central nervous system. We conducted a series of human experiments with 5 or 10 male subjects in each experiment. METHODS: The air temperature in the climatic chamber was maintained at 20 to 24°C. The subjects wore suits perfused with 25°C…
Sustaining biological welfare for our future through consistent science
Physiological anthropology presently covers a very broad range of human knowledge and engineering technologies. This study reviews scientific inconsistencies within a variety of areas: sitting posture; negative air ions; oxygen inhalation; alpha brain waves induced by music and ultrasound; 1/f fluctuations; the evaluation of feelings using surface electroencephalography; Kansei; universal design; and anti-stress issues. We found that the inconsis…
Effects of blue pulsed light on human physiological functions and subjective evaluation
BACKGROUND: It has been assumed that light with a higher irradiance of pulsed blue light has a much greater influence than that of light with a lower irradiance of steady blue light, although they have the same multiplication value of irradiance and duration. We examined the non-visual physiological effects of blue pulsed light, and determined whether it is sensed visually as being blue. FINDINGS: Seven young male volunteers participated in the s…
The Effect of Season and Light Intensity on the Core Interthreshold Zone
The hypothesis tested in the present study is a seasonal difference in the core interthreshold zone (CIZ), as we suggested in an earlier study that individual awareness of heat may change the CIZ due to thermoregulatory behavior. A series of human experiments were carried out in a climatic chamber in January and August of 2009 and January of 2010. The air temperature in the chamber was controlled at 20-24°C. Subjects wore a water-perfused suit th…
Effects of Parametric Speaker Sound on Physiological Functions during Mental Task
In recent years, parametric speakers have been used in various circumstances. However, nothing has yet been demonstrated about the safety of parametric speakers for the human body. Therefore, we studied their effects on physiological functions. Nine male subjects participated in this study. They completed three consecutive sessions: a 20-min quiet period as a baseline, a 45-min mental task period with a general speaker or a parametric speaker, an…
The Reproducibility of Cardiovascular Response to a Mental Task
The present study investigated the reproducibility of cardiovascular responses by presenting a mental task to eight healthy subjects four times at intervals of one year and of several days. Subjects performed a mental subtraction task at the same time of day and under the same conditions. For each experiment day, systolic and diastolic blood pressure (SBP and DBP), mean arterial pressure (MAP), cardiac output (CO), heart rate (HR), stroke volume …
Changes of Muscular Load with Aging in the Motion of Pulling up Disposable Diapers
To elucidate how aging affects the muscular load required for pulling up pants-style disposable diapers, and why some elderly people cannot pull up the rear of their disposable diapers well, we evaluated the electromyogram (EMG) of 8 young subjects (21.5+/-1.5 years) and 7 elderly subjects (71.6+/-6.1 years). EMG was measured for four muscles--biceps brachii, deltoid, brachioradialis, and flexor carpi ulnaris. We evaluated the muscular load durin…
Relationship between Muscular Strength and Deflection Characteristics of the Center of Foot Pressure During Landing after Crossover Stepping in the Elderly
This study aimed to investigate the relationship between the muscular strength of the lower extremity in a load side and the characteristics of center of foot pressure (COP) during landing after crossover stepping in the elderly. The study population comprised 8 elderly subjects (average age, 75.8+/-8.0 years) and 9 young individuals (average age, 21.6+/-2.5 years). Using a separation-type force plate, we measured the deflection characteristics o…
Time-of-day-dependent Effects of Monochromatic Light Exposure on Human Cognitive Function
Light elicits non-visual effects on a wide range of biological functions and behavior. These effects are mediated by a melanopsin-based photoreceptor system that is very sensitive to blue light (440-480 nm) relative to the three-cone visual photopic system. The aim of the current study was to assess the time-of-day-dependent effects of two different wavelength monochromatic lights at 458 nm and 550 nm on human cognitive function. We conducted an …
Individual Variability in the Core Interthreshold Zone as Related to Body Physique, Somatotype, and Physical Constitution
For evaluating the effect of body physique, somatotype, and physical constitution on individual variability in the core interthreshold zone (CIZ), data from 22 healthy young Japanese male subjects were examined. The experiment was carried out in a climatic chamber in which air temperature was maintained at 20-24 degrees C. The subjects' body physique and the maximum work load were measured. Somatotype was predicted from the Heath-Carter Somatotyp…
Comparison of an Accelerometer and a Condenser Microphone for Mechanomyographic Signals during Measurement of Agonist and Antagonist Muscles in Sustained Isometric Muscle Contractions
The purpose of this study was to investigate the influence of the force tremor (FT) on mechanomyographic (MMG) signals recorded by a condenser microphone (MIC) and an accelerometer (ACC) during measurement of agonist and antagonist muscles in sustained isometric contractions. Surface electromyographic (EMG) signals and MMG signals by MIC (MMG-MIC) and ACC (MMG-ACC) were recorded simultaneously on biceps brachii (BB) and triceps brachii (TB). Foll…
Influence of Force Tremor on Mechanomyographic Signals Recorded with an Accelerometer and a Condenser Microphone during Measurement of Agonist and Antagonist Muscles in Voluntary Submaximal Isometric …
The purpose of this study was to investigate the influence of force tremor (FT) on the mechanomyogram (MMG) recorded by a condenser microphone (MIC) and an accelerometer (ACC) for the measurement of agonist and antagonist muscles during submaximal isometric contractions. Following determination of the isometric maximum voluntary contraction (MVC), 10 male subjects were asked to perform elbow flexion and extension at 20%, 40%, 60%, and 80% MVC. Su…
The Relation between the Changes of Postural Achievement, Lower Limb Muscle Activities, and Balance Stability in Three Different Deep-squatting Postures
Deep squatting places a burden on the lower limb muscles and influences postural balance. We attempted to determine the effects of postural changes on the rectus femoris, tibialis anterior, gastrocnemius, soleus, and extensor digitorum brevis muscles during squatting in 8 healthy male subjects. Three squatting conditions were involved: full squatting (FS), tiptoe squatting (TT), and tiptoe squatting on a 15 degrees slope (TTS), performed randomly…
Use of Frequency Domain Analysis of Skin Conductance for Evaluation of Mental Workload
A specially designed mental task was performed by 16 subjects for frequency domain analysis of skin conductance (SC) to evaluate mental workload. The task was to memorize target letters, detect them within a 4 x 4 alphabet arrangement, and answer whether the number of targets contained in the arrangement corresponded to a randomly displayed number. As the number of target letters increased, the score for the card-sort NASA Task Load Index (CSTLX)…
Effects of Monochromatic Light on Time Sense for Short Intervals
We examined the effects of monochromatic light on the time sense and the central nervous system. Nine young adult volunteers participated in this study. They were exposed to red-light and blue-light environments (illuminance was kept at 310 lx). We evaluated the time sense by time-production tests of 90 s and 180 s and measured the P300 event-related potentials during an auditory oddball task. The 90-s time intervals produced by subjects in the t…
Individual Variability in the Peripheral and Core Interthreshold Zones
The purpose of the study was to investigate the degree of subject variability in the peripheral and core temperature thresholds of the onset of shivering and sweating. Nine healthy young male subjects participated in three trials. In the first two trials, wearing only shorts, they were exposed to air temperatures of 5 degrees C and 40 degrees C until the onset of shivering and sweating, respectively. In the second experiment, subjects wore a wate…
The Effect of Aging on the Backward Stepping Reaction as Estimated from the Velocity of Center of Foot Pressure and Muscular Strength
By estimating the deflection velocity from the center of foot pressure (COP), this study aims to prove that the characteristics of the backward stepping reaction in the elderly are related to the strength of the antigravity muscles. The participants in this study were 10 elderly (average age 75.6+/-7.6 years) and 13 young (average age 22.0+/-2.6 years) subjects. Using force plate analysis, we measured the shift in the deflection velocity (V-RMS) …
Comparison of Stress Responses between Mental Tasks and White Noise Exposure
The purpose of this study was to compare the cardiovascular responses to different types of mental stress. Ten healthy males performed a mental arithmetic task (MA) on one day and were exposed to white noise (WN, 80dB) on another day. Both the MA and the WN were composed of four 5-min consecutive periods with a 3-min rest between them. On each day, the systolic and diastolic blood pressure (SBP and DBP), mean arterial pressure (MAP), cardiac outp…
Different Types of Circulatory Responses to Mental Tasks
The present study investigated the circulatory responses to two mental tasks. Forty males and females performed a mental subtraction task and a color-word task. During each task, the systolic and diastolic blood pressure, mean arterial pressure, heart rate, stroke volume, cardiac output, and total peripheral resistance were measured as cardiovascular indices for a 5-min baseline, a 5-min task period, and a 10-min recovery period. As for the resul…
Effects of Object Color Stimuli on Human Brain Activities in Perception and Attention Referred to EEG Alpha Band Response
This study was designed to investigate the physiological effects of color in terms of blood pressure and the results of electroencephalogram (EEG) as subjects looked at the sheets of paper of various colors. A questionnaire was also used to assess psychological effects. Three colors (red, green, blue) were shown to each subject in randomized order. The various colors showed distinctly different effects on the mean power of the alpha band, theta b…
The Influence of Taste Stimuli and Illumination on Electrogastrogram Measurements
An electrogastrogram (EGG) is considered to be an index to the autonomic nervous system of the digestive organs. In the present study, we attempted to clarify whether or not an EGG can be used to evaluate the influence of illumination, and what kinds of effect taste stimuli and illumination have on the autonomic nervous system. In this study, we used the ratio of the normal wave component of the EGG (EGG-NR: 2-4.5 cpm power/1-10 cpm power) and th…
Diurnal Changes of ERP Response to Sound Stimuli of Varying Frequency in Morning-type and Evening-type Subjects
In order to study the cognitive function rhythm related to the auditory frequency system for people who prefer to be active in the morning and at night, we conducted an experiment during morning (09:00), evening (17:00) and late-night (01:00) periods. On the basis of a morningness/eveningness questionnaire, six moderately morning-type subjects (M-types) and seven evening-type subjects (E-types) were selected. Diurnal variation of event-related po…
Exposure to Bright Light Modifies HRV Responses to Mental Tasks during Nocturnal Sleep Deprivation
This study was intended to determine the effects of continuous bright light exposure on cardiovascular responses, particularly heart rate variability (HRV), at rest and during performance of mental tasks with acute nocturnal sleep deprivation. Eight healthy male subjects stayed awake from 21.00 to 04.30 hours under bright (BL, 2800 lux) or dim (DL, 120 lux) light conditions. During sleep deprivation, mental tasks (Stroop color-word conflict test:…
Cardiac Output of 10- to 11-year-old Children during Exercise under Different Ambient Temperatures
Cardiac output (Q) was measured by the CO2 rebreathing method in 10 boys and 9 girls. They performed cycle ergometer exercises at 300 and 450kgm/min in ambient temperatures kept at 20, 30, and 40°C. For a given oxygen uptake (Vo2), stroke volume (SV) tended to be reduced and heart rate (HR) increased in a 40°C environment in both sexes. Accordingly, Q at 40°C was maintained at a level similar to that in cooler conditions. A lower HR and a higher …
Effects of Object Color Stimuli on Human Brain Activities in Perception and Attention Referred to EEG Alpha Band Response
This study was designed to investigate the physiological effects of color in terms of blood pressure and the results of electroencephalogram (EEG) as subjects looked at the sheets of paper of various colors. A questionnaire was also used to assess psychological effects. Three colors (red, green, blue) were shown to each subject in randomized order. The various colors showed distinctly different effects on the mean power of the alpha band, theta b…
The Influence of Taste Stimuli and Illumination on Electrogastrogram Measurements
An electrogastrogram (EGG) is considered to be an index to the autonomic nervous system of the digestive organs. In the present study, we attempted to clarify whether or not an EGG can be used to evaluate the influence of illumination, and what kinds of effect taste stimuli and illumination have on the autonomic nervous system. In this study, we used the ratio of the normal wave component of the EGG (EGG-NR: 2-4.5 cpm power/1-10 cpm power) and th…
The Effect of Season and Light Intensity on the Core Interthreshold Zone
The hypothesis tested in the present study is a seasonal difference in the core interthreshold zone (CIZ), as we suggested in an earlier study that individual awareness of heat may change the CIZ due to thermoregulatory behavior. A series of human experiments were carried out in a climatic chamber in January and August of 2009 and January of 2010. The air temperature in the chamber was controlled at 20-24°C. Subjects wore a water-perfused suit th…
Effects of Parametric Speaker Sound on Physiological Functions during Mental Task
In recent years, parametric speakers have been used in various circumstances. However, nothing has yet been demonstrated about the safety of parametric speakers for the human body. Therefore, we studied their effects on physiological functions. Nine male subjects participated in this study. They completed three consecutive sessions: a 20-min quiet period as a baseline, a 45-min mental task period with a general speaker or a parametric speaker, an…
Time-of-day-dependent Effects of Monochromatic Light Exposure on Human Cognitive Function
Light elicits non-visual effects on a wide range of biological functions and behavior. These effects are mediated by a melanopsin-based photoreceptor system that is very sensitive to blue light (440-480 nm) relative to the three-cone visual photopic system. The aim of the current study was to assess the time-of-day-dependent effects of two different wavelength monochromatic lights at 458 nm and 550 nm on human cognitive function. We conducted an …
Individual Variability in the Core Interthreshold Zone as Related to Body Physique, Somatotype, and Physical Constitution
For evaluating the effect of body physique, somatotype, and physical constitution on individual variability in the core interthreshold zone (CIZ), data from 22 healthy young Japanese male subjects were examined. The experiment was carried out in a climatic chamber in which air temperature was maintained at 20-24 degrees C. The subjects' body physique and the maximum work load were measured. Somatotype was predicted from the Heath-Carter Somatotyp…
Effects of Monochromatic Light on Time Sense for Short Intervals
We examined the effects of monochromatic light on the time sense and the central nervous system. Nine young adult volunteers participated in this study. They were exposed to red-light and blue-light environments (illuminance was kept at 310 lx). We evaluated the time sense by time-production tests of 90 s and 180 s and measured the P300 event-related potentials during an auditory oddball task. The 90-s time intervals produced by subjects in the t…
Individual Variability in the Peripheral and Core Interthreshold Zones
The purpose of the study was to investigate the degree of subject variability in the peripheral and core temperature thresholds of the onset of shivering and sweating. Nine healthy young male subjects participated in three trials. In the first two trials, wearing only shorts, they were exposed to air temperatures of 5 degrees C and 40 degrees C until the onset of shivering and sweating, respectively. In the second experiment, subjects wore a wate…
Diurnal Changes of ERP Response to Sound Stimuli of Varying Frequency in Morning-type and Evening-type Subjects
In order to study the cognitive function rhythm related to the auditory frequency system for people who prefer to be active in the morning and at night, we conducted an experiment during morning (09:00), evening (17:00) and late-night (01:00) periods. On the basis of a morningness/eveningness questionnaire, six moderately morning-type subjects (M-types) and seven evening-type subjects (E-types) were selected. Diurnal variation of event-related po…
Exposure to Bright Light Modifies HRV Responses to Mental Tasks during Nocturnal Sleep Deprivation
This study was intended to determine the effects of continuous bright light exposure on cardiovascular responses, particularly heart rate variability (HRV), at rest and during performance of mental tasks with acute nocturnal sleep deprivation. Eight healthy male subjects stayed awake from 21.00 to 04.30 hours under bright (BL, 2800 lux) or dim (DL, 120 lux) light conditions. During sleep deprivation, mental tasks (Stroop color-word conflict test:…
Mean Skin Temperature. Comparison of the formulas calculating it, combined effect on it of air temperature and muscular work, and a nomogram for estimating it from the heart rate and oxygen intake
A number of studies on weighting and unweighting formulas for calculating mean skin temperature are reviewed. From the view point of simplicity of experimental technique and calculation in field studies, a four-p int mean based on a system devised by Ramanathan (1964) is noted especially.The present authors concluded from a review of many previous studies concerning mean skin temperasure during muscular works that increases in cutaneous venous to…
Effects of Increased Ambient Pressure on Cardiopulmonary Functions during Isometric Elbow Flexion
Eight young male subjects, 21-25 years of age, were studied during isometric elbow flexion at each of 1.0, 1.5, 2.0, 2.5 and 3.0 atm abs ambient pressure to observe the effects of increased ambient pressure on pulmonary ventilation, carbon dioxide output, ratio of carbon dioxide annexing, oxygen uptake, ratio of oxygen removal and heart rate.The analysis of variance for each of these items showed that pulmonary ventilation, carbon dioxide output …
Heart Rate as an Index of Oxygen Intake
The purpose of this study is to investigate the relibaility and validity of prediction of the oxygen intake during works on the basis of heart rate at work.During four kinds of standard treadmill walking of 3.6km/h with a slope varying from o to 15 degrees and four kinds of standard bicycle ergometer work of o to 900kgm/min, the oxygen intake and heart rate were measured on four young adult males(Table1).For the whole subjects and for each indivi…
Effect of Posture on Cardiac Output under Different Air Temperature Conditions
Cardiac output during rest in seven postures was determined by a CO2 rebreathing method in 12 male students under the air temperature conditions of 20°C, 30°C, and 40°C. The mixed venous C02 pressure was calculated from the rise of the CO2 percent in a rubber bag during rebreathing. Arterial C02 pressure was assumed to be the same as in end-tidal air. CO2 output was measured by the Douglas bag technique. Fick's equation was used for calculation o…
Alterations of Cardiac Output, Stroke Volume, and Heart Rate during 3 Hours of Exercise in Different Ambient Temperatures
The alterations of cardiovascular responeses during 3 hours of treadmill walking in five thermal conditions, 20, 25, 30, 35, and 40°C, were studied in eight normal young men. Cardiac output (determined with the CO2 rebreathing method), heart rate, oxygen uptake, rectal temperature, and mean skin temperature were measured at 10th minute, 1st hour, 2nd hour, and 3rd hour of exercise. Cardiac output in the 40°C showed a tendency to be higher than in…
Relationships between subcutaneous fat and increase in body temperature during exercise in a warm environment
The relationships between increase in rectal temperature and subcutaneous fat were studied during exercise in 10 male Japanese, aged 18 to 31 years old. The skinfold thicknesses were measured at six sites, i.e., triceps, chest, abdomen, iliac, subscapula, and thigh. Mean skinfold thickness (MSF), body density, body fat %, lean body mass (LBM), and body surface area(BSA) were calculated by the prediction equations. The subjects dressed only shorts…
Cardiac Output of 10- to 11-year-old Children during Exercise under Different Ambient Temperatures
Cardiac output (Q) was measured by the CO2 rebreathing method in 10 boys and 9 girls. They performed cycle ergometer exercises at 300 and 450kgm/min in ambient temperatures kept at 20, 30, and 40°C. For a given oxygen uptake (Vo2), stroke volume (SV) tended to be reduced and heart rate (HR) increased in a 40°C environment in both sexes. Accordingly, Q at 40°C was maintained at a level similar to that in cooler conditions. A lower HR and a higher …
Comparison of Cardiac Output during Work with Arms or Legs at Equal Work Loads
The effects of arm work and leg work on cardiac output (Q) and some other physiological parameters were studied in ten Japanese males. The subjects performed the work using arms or legs in a sitting position, with equal work loads of 150, 300, and 450kgm/min. Oxygen uptake (Vo2) and heart rate (HR) during arm work were significantly (P<0.01) higher than those during leg work at the loads of 300 and 450 kgm/min. With the increase of work loads, st…
Diurnal Changes of ERP Response to Sound Stimuli of Varying Frequency in Morning-type and Evening-type Subjects
In order to study the cognitive function rhythm related to the auditory frequency system for people who prefer to be active in the morning and at night, we conducted an experiment during morning (09:00), evening (17:00) and late-night (01:00) periods. On the basis of a morningness/eveningness questionnaire, six moderately morning-type subjects (M-types) and seven evening-type subjects (E-types) were selected. Diurnal variation of event-related po…
Exposure to Bright Light Modifies HRV Responses to Mental Tasks during Nocturnal Sleep Deprivation
This study was intended to determine the effects of continuous bright light exposure on cardiovascular responses, particularly heart rate variability (HRV), at rest and during performance of mental tasks with acute nocturnal sleep deprivation. Eight healthy male subjects stayed awake from 21.00 to 04.30 hours under bright (BL, 2800 lux) or dim (DL, 120 lux) light conditions. During sleep deprivation, mental tasks (Stroop color-word conflict test:…
Effects of Monochromatic Light on Time Sense for Short Intervals
We examined the effects of monochromatic light on the time sense and the central nervous system. Nine young adult volunteers participated in this study. They were exposed to red-light and blue-light environments (illuminance was kept at 310 lx). We evaluated the time sense by time-production tests of 90 s and 180 s and measured the P300 event-related potentials during an auditory oddball task. The 90-s time intervals produced by subjects in the t…
Individual Variability in the Peripheral and Core Interthreshold Zones
The purpose of the study was to investigate the degree of subject variability in the peripheral and core temperature thresholds of the onset of shivering and sweating. Nine healthy young male subjects participated in three trials. In the first two trials, wearing only shorts, they were exposed to air temperatures of 5 degrees C and 40 degrees C until the onset of shivering and sweating, respectively. In the second experiment, subjects wore a wate…
The Effect of Aging on the Backward Stepping Reaction as Estimated from the Velocity of Center of Foot Pressure and Muscular Strength
By estimating the deflection velocity from the center of foot pressure (COP), this study aims to prove that the characteristics of the backward stepping reaction in the elderly are related to the strength of the antigravity muscles. The participants in this study were 10 elderly (average age 75.6+/-7.6 years) and 13 young (average age 22.0+/-2.6 years) subjects. Using force plate analysis, we measured the shift in the deflection velocity (V-RMS) …
Comparison of Stress Responses between Mental Tasks and White Noise Exposure
The purpose of this study was to compare the cardiovascular responses to different types of mental stress. Ten healthy males performed a mental arithmetic task (MA) on one day and were exposed to white noise (WN, 80dB) on another day. Both the MA and the WN were composed of four 5-min consecutive periods with a 3-min rest between them. On each day, the systolic and diastolic blood pressure (SBP and DBP), mean arterial pressure (MAP), cardiac outp…
Different Types of Circulatory Responses to Mental Tasks
The present study investigated the circulatory responses to two mental tasks. Forty males and females performed a mental subtraction task and a color-word task. During each task, the systolic and diastolic blood pressure, mean arterial pressure, heart rate, stroke volume, cardiac output, and total peripheral resistance were measured as cardiovascular indices for a 5-min baseline, a 5-min task period, and a 10-min recovery period. As for the resul…
Effects of Object Color Stimuli on Human Brain Activities in Perception and Attention Referred to EEG Alpha Band Response
This study was designed to investigate the physiological effects of color in terms of blood pressure and the results of electroencephalogram (EEG) as subjects looked at the sheets of paper of various colors. A questionnaire was also used to assess psychological effects. Three colors (red, green, blue) were shown to each subject in randomized order. The various colors showed distinctly different effects on the mean power of the alpha band, theta b…
The Influence of Taste Stimuli and Illumination on Electrogastrogram Measurements
An electrogastrogram (EGG) is considered to be an index to the autonomic nervous system of the digestive organs. In the present study, we attempted to clarify whether or not an EGG can be used to evaluate the influence of illumination, and what kinds of effect taste stimuli and illumination have on the autonomic nervous system. In this study, we used the ratio of the normal wave component of the EGG (EGG-NR: 2-4.5 cpm power/1-10 cpm power) and th…
Comparison of an Accelerometer and a Condenser Microphone for Mechanomyographic Signals during Measurement of Agonist and Antagonist Muscles in Sustained Isometric Muscle Contractions
The purpose of this study was to investigate the influence of the force tremor (FT) on mechanomyographic (MMG) signals recorded by a condenser microphone (MIC) and an accelerometer (ACC) during measurement of agonist and antagonist muscles in sustained isometric contractions. Surface electromyographic (EMG) signals and MMG signals by MIC (MMG-MIC) and ACC (MMG-ACC) were recorded simultaneously on biceps brachii (BB) and triceps brachii (TB). Foll…
Influence of Force Tremor on Mechanomyographic Signals Recorded with an Accelerometer and a Condenser Microphone during Measurement of Agonist and Antagonist Muscles in Voluntary Submaximal Isometric …
The purpose of this study was to investigate the influence of force tremor (FT) on the mechanomyogram (MMG) recorded by a condenser microphone (MIC) and an accelerometer (ACC) for the measurement of agonist and antagonist muscles during submaximal isometric contractions. Following determination of the isometric maximum voluntary contraction (MVC), 10 male subjects were asked to perform elbow flexion and extension at 20%, 40%, 60%, and 80% MVC. Su…
The Relation between the Changes of Postural Achievement, Lower Limb Muscle Activities, and Balance Stability in Three Different Deep-squatting Postures
Deep squatting places a burden on the lower limb muscles and influences postural balance. We attempted to determine the effects of postural changes on the rectus femoris, tibialis anterior, gastrocnemius, soleus, and extensor digitorum brevis muscles during squatting in 8 healthy male subjects. Three squatting conditions were involved: full squatting (FS), tiptoe squatting (TT), and tiptoe squatting on a 15 degrees slope (TTS), performed randomly…
Use of Frequency Domain Analysis of Skin Conductance for Evaluation of Mental Workload
A specially designed mental task was performed by 16 subjects for frequency domain analysis of skin conductance (SC) to evaluate mental workload. The task was to memorize target letters, detect them within a 4 x 4 alphabet arrangement, and answer whether the number of targets contained in the arrangement corresponded to a randomly displayed number. As the number of target letters increased, the score for the card-sort NASA Task Load Index (CSTLX)…
Relationship between Muscular Strength and Deflection Characteristics of the Center of Foot Pressure During Landing after Crossover Stepping in the Elderly
This study aimed to investigate the relationship between the muscular strength of the lower extremity in a load side and the characteristics of center of foot pressure (COP) during landing after crossover stepping in the elderly. The study population comprised 8 elderly subjects (average age, 75.8+/-8.0 years) and 9 young individuals (average age, 21.6+/-2.5 years). Using a separation-type force plate, we measured the deflection characteristics o…
Time-of-day-dependent Effects of Monochromatic Light Exposure on Human Cognitive Function
Light elicits non-visual effects on a wide range of biological functions and behavior. These effects are mediated by a melanopsin-based photoreceptor system that is very sensitive to blue light (440-480 nm) relative to the three-cone visual photopic system. The aim of the current study was to assess the time-of-day-dependent effects of two different wavelength monochromatic lights at 458 nm and 550 nm on human cognitive function. We conducted an …
Individual Variability in the Core Interthreshold Zone as Related to Body Physique, Somatotype, and Physical Constitution
For evaluating the effect of body physique, somatotype, and physical constitution on individual variability in the core interthreshold zone (CIZ), data from 22 healthy young Japanese male subjects were examined. The experiment was carried out in a climatic chamber in which air temperature was maintained at 20-24 degrees C. The subjects' body physique and the maximum work load were measured. Somatotype was predicted from the Heath-Carter Somatotyp…
The Reproducibility of Cardiovascular Response to a Mental Task
The present study investigated the reproducibility of cardiovascular responses by presenting a mental task to eight healthy subjects four times at intervals of one year and of several days. Subjects performed a mental subtraction task at the same time of day and under the same conditions. For each experiment day, systolic and diastolic blood pressure (SBP and DBP), mean arterial pressure (MAP), cardiac output (CO), heart rate (HR), stroke volume …
Medicine (28 works) · Internal Medicine (18 works) · Psychology (13 works) · Physics (12 works) · Heart rate (11 works) · Blood pressure (9 works) · Chemistry (9 works) · Thermoregulation and physiological responses (9 works) · Biology (8 works) · Cardiology (8 works)