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Volume 49 (2000)
- Issue 6 Pages 621-
- Issue 5 Pages 543-
- Issue 4 Pages 459-
- Issue 3 Pages 355-
- Issue 2 Pages 225-
- Issue 1 Pages 1-
Volume 49, Issue 2
Displaying 1-13 of 13 articles from this issue
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DAISUKE MASUDA, RYUUJI NOHARA2000 Volume 49 Issue 2 Pages 225-236
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
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SHINICHI DEMURA, SUSUMU SATO, JINZABURO MATSUZAWA, YOHEI NODA, HISAYOS ...2000 Volume 49 Issue 2 Pages 237-246
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study was to propose useful ADLs (activities of daily living) and scales to estimate ADL ability on community older people from the viewpoints of aging, physical fitness level, and interrelationship among ADL. The survey constructing of 15 ADL items and physical fitness test of Ministry of Education, Science and Culture were carried out on 458 older people. Each ADL item was constructed with 3 level scales.
As the results of this study, the following 12 ADLs were proposed as useful ADL items; in the locomotion domain, jumping across a ditch, walking, running, up and down stairs, and transfer; in the manipulation domain, taking bedding in and out, buttoning a shirt; in stability domain, standing in the bus or train, dressing while standing (trousers), standing on one foot with eyes open; in the posture-change domain, sitting up, standing up from the floor. These items were significantly related to age and physical fitness elements contributed largely to achievement of each ADL. Since significant high correlation was found between the index using 12 ADL items and that using 15 items, it is considered that the 12 items scale can account for the variance corresponded enough to that of 15 items scale, and that the new index is practical and simple.
In further research, it will be required to examine validity of each ADL item and index by using more large sample, and to clarify the relation to various factors influenced to ADL ability level.View full abstractDownload PDF (1326K) -
SHUICHI MACHIDA, KEIZO KOBAYASHI, MITSUO NARUSAWA2000 Volume 49 Issue 2 Pages 247-255
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSWe examined the effect of running training on regional cardiac myosin isozyme composition in rats. Male Sprague-Dawley strain rats (4 weeks old) were used, and divided into two groups: sedentary control (C) and trained (T) groups. The T group was trained by treadmill running (40 m/min, 1h/day, 5 days/week, for 12 weeks) . At 16 weeks old, their hearts were excised. The left ventricle was separated into the subendocardium (Endo) and subepicardium (Epi) by dissecting the ventricle at the mid-wall. The ventricular myosin isozymes were examined by electrophoresis on pyrophosphate gel under non-dissociating conditions. The results showed the following: 1) The relative heart weight of the T group was significantly higher than the C group. 2) Left ventricular myosin isozyme composition showed a region-specific distribution in the C rats, and the proportion of V3 myosin or β-myosin heavy chain in the Endo was significantly higher than that of the Epi. However, the training had no effect on the cardiac myosin isozyme in either portion. 3) The activity of citrate synthase did not show transmural gradient in the ventricle of C animals. Training had no effect on the activities of either portion. 4) The activity of lactate dehydrogenase (LDH) showed transmural gradient in the ventricle of C rats. Training-induced changes in the activity of LDH were found in both portions, therefore, training abolished the transmural gradient in the activity of LDH, suggesting a corresponding redistribution of the myocardial work load.
These results indicate that running training might induce the redistribution of the myocardial work load, whereas the stimulation apparently has no effect on the regional distribution of cardiac myosin isozyme composition.View full abstractDownload PDF (1116K) -
SAKURA TANAKA2000 Volume 49 Issue 2 Pages 257-266
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSIt is well known that the successive H-reflexes, evoked by stimulation of constant intensity, show considerable variability. To investigate physiological factors affecting this H-reflex variability, we elicited the successive soleus H-reflexes by stimulating the post-tibial nerve at a constant strength during the standing and supine position. Comparison between the soleus H-reflex amplitudes, recorded from 7 subjects showed that the variability of H-reflexes on standing were greater than those in the supine position. Then, spectral analysis was used to evaluate the degree of the H-reflex variability and the effect of autonomic activation. The total power (TP) value of the H-reflex on standing (0.2961±0.0618 mV⋅mV) was significantly greater (p<0.001) than that in a supine position (0.0565±0.0080mV⋅mV), which may indicate that the soleus H-reflexes while standing have a large variability. Such variation of the H-reflex may be explained by a change in the soleus motoneuron activity. The values of peak power frequency (PPF) obtained from the soleus H-reflex while both standing and supine, were about 0.17Hz. This would suggest that variations in H-reflexes were influenced by respiration. The electrocardiogram (ECG) and respiration curves were recorded simultaneously when successive soleus H-reflexes were evoked. Variations of RR interval obtained from ECG recordings were analyzed as well as H-reflex variations and the TP values in the supine position (1254.4676±150.3057 msec⋅msec) were significantly (p<0.001) larger than those while standing (566.0482±60.4576 msec⋅msec) . Furthermore, we examined the relationship between the variability of H-reflex and RR interval. There were significant correlations between the H-reflex and RR interval when standing in TP (r= -0.3886, p=0.0254) and PPF (r=0.5042, p=0.0028) values. Besides, the amplitudes of H-reflex while standing that evoked during both the inspiratory and expiratory period were increased. This increase in H-reflex might be due to the effect of postural elements of the respiratory impulse. These results indicated that the variability of soleus H-reflexes at standing might imply autonomic activation and descending effects from central nervous system depending on postural control.View full abstractDownload PDF (1222K) -
SACHIYO AKIYAMA, YOSHIAKI NISHIHIRA, ARIHIRO HATTA, MASAKI FUMOTO, TAK ...2000 Volume 49 Issue 2 Pages 267-276
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSElectrophysiologic effects of physical exercise were investigated by comparing a training group and non-training group. ERPs were recorded by oddball paradigm using auditory stimuli as well as count and reaction tasks. EMG-RT was recorded during the reaction task. No reliable exercise effects on N100 amplitudes or latencies were observed. Concerning P300 amplitudes, no significant difference between the training group and non-training group was seen although P300 latencies of the training group were significantly shorter than those of the non-training group in the count task. Moreover, EMG-RT of the training group was significantly shorter than that of the non-training group.
These findings suggest that the long-term physical exercise improved the efficiency of informa-tion processing and superior cognitive function in the brain.View full abstractDownload PDF (1131K) -
TAKASHI KOJIMA2000 Volume 49 Issue 2 Pages 277-284
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study was to determine whether aging influences sex-related differences in plasmin and plasmin-inhibiting activities in rats. We measured plasmin activity and plasmininhibiting activity in 5-, 12-, 45-, and 60-week-old male and female rats; and we also examined the effects of a gonadectomy and sex hormone treatments in adult male and female rats. The present study showed that the plasmin activity was higher in male rats than in females in all four age groups, which confirmed our previous findings. However, there was no significant sex-related difference in plasmin-inhibiting activity among the four age groups. An increase in age induced a decrease in plasmin activity and plasmin-inhibiting activity in both male and female rats. An ovariectomy significantly boosted plasmin and plasmin-inhibiting activity in female rats. Estradiol treatment induced a decrease in plasmin activity of orchiectomized male and ovariectomized female rats, and the plasmininhibiting activity of ovariectomized female rats. However, an orchiectomy slightly boosted plasmininhibiting activity in male rats. Testosterone treatment, on the other hand, did not significantly influence plasmin activity and plasmin-inhibiting activity in orchiectomized male and ovariectomized female rats.
It is suggested that estrogen regulates the system of plasmin and plasmin-inhibiting activities in rats, and a decrease of the plasmin and plasmin-inhibiting activities in aged rats is one of the reasons for more frequent thrombotic formation in aged rats.View full abstractDownload PDF (1020K) -
TOSHIAKI WASAKA, YOSHIAKI NISHIHIRA, HIDEO ARAKI2000 Volume 49 Issue 2 Pages 285-293
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe somatosensory evoked potential (SEP) is attenuated (gating) and the spinal motoneuron pool is facilitated before and during movement. However, the relationship between these changes has not been elucidated. In the present study, the SEP and the evoked electromyogram were simultaneously recorded during a discriminative reaction task in seven healthy subjects. Electrical stimulation applied to the posterior tibial nerve in the popliteal fossa was used as a response signal. The experimental condition were: 1) full relaxation and no response to either right or left stimulation (Control) ; 2) no response to right stimulation and quick contraction of right ankle with left stimulation (L-R) ; 3) no response to left stimulation and quick contraction of right ankle with right stimulation (R-R) . Right and left legs were randomly stimulated under each condition. The H-response gains of the right leg with movement were significantly facilitated compared to the left leg without movement in L-R and R-R conditions. The results indicated that movement enhanced the motoneuron excitability regardless of sensory concentration. In the L-R condition, N 40 at Cz evoked by left operative stimulation that produced right leg movement was significantly increased. However, in the R-R condition, it was significantly attenuated when it was recorded by right operative stimulation that produced right leg movement. These results indicated that concentration on the operative stimulation enhanced the N 40 gain and it reflected the concentration on sensory information, but simultaneously induced the movement, and its gain was strongly controlled by the motor system.View full abstractDownload PDF (1233K) -
—MEASURED BY A CERVICAL EXTENSION MACHINE—KAORU TSUYAMA, KOUICHI NAKAZATO, HITONE FUJISHIRO, HIROYUKI NAKAJIMA2000 Volume 49 Issue 2 Pages 295-305
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study is to evaluate and compare isometric cervical extension strength (extension strength) of college American football players belonging to different level leagues at the eight cervical positions measured by a cervical extension machine (Medx Inc.) and give some suggestions for preventing neck injuries. The subjects were American football players at N University (n=41) belonging to the first-level league and at G University (n=32) belonging to the third-level league. The findings were as follows.
1. The isometric cervical extension strength/body weight of players at N University was sig-nificantly higher than that of G University at 72°, 54°and 36° (a neutral cervical position) .
2. The extension strength/body weight of the linemen at N University was significantly higher at 108°, 54°and 36°than that of the linemen at G University. While there were no significant differences between universities in the eight cervical positions of back players herein referred to as‘backs’.
In conclusion, it was shown that there were significant differences in the extension strength and the extension strength/body weight between teams of different levels. The differences tended to be larger between the linemen than between the backs. Therefore, it was suggested that the evaluation of neck muscle strength was important for preventing neck injuries especially caused by a mismatch of players at different performance levels.View full abstractDownload PDF (1137K) -
TAKESHI KANEDA, YOSHIAKI NISHIHIRA, ARIHIRO HATTA, MASAKI FUMOTO, MASA ...2000 Volume 49 Issue 2 Pages 307-314
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSWe examined here, changes in event-related potentials (ERPs) in eighteen children from 7 to 12 years and twelve adults. In addition to ERPs, we examined changes of EMG-RT. Subjects performed an auditory target discrimination task, in which 1000 Hz tones (target) and 2000 Hz tones (standard) were randomly presented with probabilities of 0.2 and 0.8.
We found P300 as most consistent component of ERPs since childhood. P300 latency and EMG-RT in children was significantly prolonged than in adults (p<0.01) . P300 amplitude in children was significantly larger than in adults (p<0.05) . We concluded that both stimulus evaluation time and response selection time in children are more prolonged than that in adults, although ERPs is confirmed in children.View full abstractDownload PDF (868K) -
HIROSHI YAMADA, TOMOHIRO KIZUKA, TADASHI MASUDA, TORU KIRYU, MORIHIKO ...2000 Volume 49 Issue 2 Pages 315-328
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study is to examine the validity of muscle fatigue evaluation using maximum voluntary torque (MVT), and to identify the dependence of individual's tolerance for fatigue on the capacity to exert MVT. In 14 young male subjects (10 regular exercisers and 4 sedentary), MVT was measured during isometric knee extension, and voluntary activation (VA), which reflects motor unit activation, was evaluated using the twitch interpolation technique. In addition, the maximum endurance time (ET) was measured, and behavior of the mean power frequency (MPF) and the average rectified value (ARV) of surface EMGs from the vastus lateralis muscle were analyzed during constant force isometric contractions of 60% MVT (short-duration fatigue task; SDF task) and 20% MVT (long-duration fatigue task; LDF task) . Correlations were examined among these five variables.
The results were as follows:
1) Subjects were divided into a high voluntary activation group (HVA group) and a low voluntary activation group (LVA group) . Four sedentary subjects were included in the latter group.
2) MVT was significantly larger in the HVA group than in the LVA group (p<0.01) . A significant positive correlation (r=0.72) was found between MVT and VA (p<0.01) .
3) A significant negative correlation (r=-0.71) was found between MVT and endurance time (ET) for the LDF task (p<0.01) . The ET was significantly longer in the LVA group than in the HVA group (p<0.01) .
4) The MPF of voluntary EMG decreased consistently, as ARV increased during isometric contraction in both tasks (p<0.01), indicating the development of fatigue in the muscle. The final change of MPF relative to the initial value was significantly greater in the SDF task than in the LDF task (p<0.05) .
5) A significant correlation (r=-0.83) was seen between the relative change in MPF and ARV in the SDF task (p<0.01) .
6) For the SDF task, the final change of MPF and ARV relative to the initial value was significantly greater in the LVA group than in the HVA group (p<0.05) .
These results indicate that tolerance for local muscle fatigue usually evaluated as maximum endurance time, may depend on individual differences in VA, the VA, in turn, depending on adapta-tion to exercise, and that there appears to exist a corresponding adaptative strategy of the neuromuscular system during fatiguing contractions. Usefulness of our procedure using the twitch interpolation technique in evaluating muscle fatigue was also suggested.View full abstractDownload PDF (3059K) -
2000 Volume 49 Issue 2 Pages 329-335
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
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2000 Volume 49 Issue 2 Pages 336-344
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
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2000 Volume 49 Issue 2 Pages 345-352
Published: April 01, 2000
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (1212K)
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