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Volume 43 (1994)
- Issue 6 Pages 473-
- Issue 5 Pages 325-
- Issue 4 Pages 241-
- Issue 3 Pages 201-
- Issue 2 Pages 145-
- Issue 1 Pages 1-
Volume 43, Issue 4
Displaying 1-10 of 10 articles from this issue
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TOSHIKAZU YOSHIKAWA, SHUNICHIRO NISHIMURA, MOTOHARU KONDO1994 Volume 43 Issue 4 Pages 241-246
Published: August 01, 1994
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (686K) -
SATORU KAWAI, HIROSHI KINOSHITA, KOMEI IKUTA1994 Volume 43 Issue 4 Pages 247-258
Published: August 01, 1994
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSA study was conducted to investigate the effects of object weight on the regulation of grip force during holding tasks using a precision grip. In addition, variations in grip force among individuals were examined. Using a force transducer-equipped grip apparatus, grip force, load force and the vertical position of the object were measured continuously while using load weights of 0.98N, 1.96N, and 2.94N under sandpaper grip surface conditions. From the recorded data, peak grip force, average static grip force, slip force, safety margin force (average static grip force-slip force), and time to stabilize the grip force from the peak grip force were evaluated.
It was found that both the slip force and safety margin force increased with object weight. The static friction coefficient, estimated from the slip force and load force, deviated from Amonton's law at a lower load force. The deviation was believed to be due to the influence of the viscoelastic nature of finger skin. An increase in safety margin force with object weight was considered to be related to the psychological reaction to the increased heaviness of the object. Indeed, in trials that included unexpected changes in object weight, the safety margin force was increased, which also seemed to be associated with the psychological reaction to uncertainty about the object's weight. A relatively large inter-subject variation was revealed for both the slip force and safety margin force.View full abstractDownload PDF (1520K) -
SOTOYUKI USUI, TSUTOMU NAKADA, RYOUSUKE OKANO, KEN-ICHI KATSUKI, KOZO ...1994 Volume 43 Issue 4 Pages 259-268
Published: August 01, 1994
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSRecently, interest has been forcused on the increasing incidence of bone fracture due to low bone mineral density (BMD) in some sportswomen. Therefore the present study attempted to elucidate important factors associated with an increase or decrease of BMD in sportswomen.
The results obtained were as follows;
(1) Ball games appeared to be the most desirable main sports. Also it appeared necessary to increase lean body mass (weight) by maintaining a higher activity of daily living (ADL) index.
(2) There were no clear nutritional factors that had a beneficial influence for increasing the BMD.
These results suggest that sufficient exercise, at least, is necessary in order to increase BMD.View full abstractDownload PDF (1174K) -
KENTARO KAWANAKA, MITSURU HIGUCHI, HAJIME OHMORI, SHIGERU KATSUTA1994 Volume 43 Issue 4 Pages 269-276
Published: August 01, 1994
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSIn this study, we investigated the possibility that GLUT4 protein concentration and mitochondrial enzyme activity is coregulated by muscle contractile activity. In the first experiment, male rats were trained by treadmill running or swimming for 3 wks and training effects in upper-and hind-limb muscle were investigated. Treadmill training program induced increases of 30% in citrate synthase activity, 51% in hexokinase activity, and 35% in GLUT4 protein concentration in hind-limb soleus muscles without causing training effects in upper-limb epitrochlearis muscles. On the other hand, swimming training program induced increases of 67% in citrate synthase activity, 139% in hexokinase activity, and 89% in GLUT4 protein concentration in epitrochlearis muscle without causing training effects in soleus muscles. These results suggest that muscle contractile activity which raises mitochondrial enzyme activity increases GLUT4 protein concentration in skeletal muscle. In a second set of experiment, we investigated relationship between muscle GLUT4 protein concentration and mitochondrial enzyme activity by use of the various type of rat muscles (soleus, plantaris, red gastrocnemius, white gastrocnemius, epitrochlearis and heart), which possese different contractile activity level. Significant correlation was observed between GLUT4 protein concentration and citrate synthase activity among different muscles (r=0.936) . They suggest that muscle GLUT4 protein concentration and mitochondrial enzyme activity level may be coregulated according to muscle contractile activity level.View full abstractDownload PDF (1770K) -
YOSHINORI OHTSUKA, NORIYUKI YABUNAKA, HIROYUKI FUJISAWA, HIRONOBU KAMI ...1994 Volume 43 Issue 4 Pages 277-282
Published: August 01, 1994
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe erythrocyte antioxidative defense system was investigated before and after a 12km run. The effect of exercise with a bicycle ergometer on this system was also examined one and seven days after the. 12km run. Five untrained healthy men, aged 18-21 years, participated in the present study. Plasma creatine kinase (CK) activity increased after running and reached a maximum on the next day (p<0.005) . Levels of the reduced form of glutathione (GSH) decreased by 24.6% after running (p<0.005), but by 7 days later the values recovered. Levels of lipid peroxides (LPO, expressed as thiobarbituric acid-reactive substances) fell slightly after running (13.4%, not significant), then showed a significant decrease on the next day (34.7%, p<0.005) and recovered by the seventh day. Neither glutathione peroxidase (GPX) nor glutathione reductase (GR) activities (with or without FAD) showed significant changes after the 12km run. Activities of catalase (CAT) were lowest after the exercise with a bicycle ergometer on the following day (p<0.05 vs. initial levels) . Levels of GSH, GPX, GR and LPO did not change after this exercise. The decreased level of GSH after the 12km run indicates the presence of oxidative stress, while moderate exercise with a bicycle ergometer does not affect the erythrocyte glutathione metabolism in untrained men. It is also suggested that catalase activity decreases after the repeated exercise.View full abstractDownload PDF (629K) -
SEIICHI NAKAI, TETSUYA YOSHIDA, AKIRA YORIMOTO, NAOKI OKAMOTO, TAKETOS ...1994 Volume 43 Issue 4 Pages 283-289
Published: August 01, 1994
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe relationship between environmental conditions and water balance during training for baseball and American football was analyzed. The environmental conditions were assessed in terms of WBGT (wet-bulb globe temperature) based on NDB (natural dry-bulb temperature), NWB (natural wet-bulb temperature) and GT (globe temperature), as WBGT=0.7NWB+0.2GT+0.1NDB,
During baseball training, a commercially available sports drink was provided ad libitum, whereas during American football training, the effect of free water intake was compared between tap-water and sports drink. The sweat rate and the amount of water consumption were significantly correlated with WBGT under each experimental condition. Body weight loss was 0.2% body wt./h during baseball training, whereas during American football training, body weight loss was 0.5%/h with tap-water and 0.4%/h with sports drink on average, revealing a significantly higher value for tap-water.
These results indicate that both sweat loss and water intake during exercise increase with WBGT, and that body weight loss is maintained at a fairly constant level during exercise with free water intake, although the loss is significantly higher when tap-water is provided.View full abstractDownload PDF (804K) -
TOMOYOSHI KOMIYAMA, TOSHIAKI FURUBAYASHI, KAZUTAKE KAWAI1994 Volume 43 Issue 4 Pages 290-299
Published: August 01, 1994
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSA study was conducted to investigate changes in the excitability of the ankle extensor and flexor motoneurons during voluntary contraction of the quadriceps femoris muscle (Quad) . For this purpose, we used a reaction time task and the H-reflex technique. Subjects lay in the prone position on a bed and performed isometric contraction of the Quad. The strength of the contraction force was about 30% of maximum.
In all subjects we observed strong facilitation of the soleus (Sol) H-reflex, which occurred from the EMG onset of vastus lateralis muscle (VL) . The pretibial muscle (TA) H-reflex was also facilitated at almost the same time as that seen in the Sol H-reflex in nine out of ten subjects. The peak of Sol and TA H-reflex facilitation appeared between 50 and 100 ms after the EMG onset of the VL, and then these facilitations gradually decreased. Weak but constant activities of the Sol and medial gastrocnemius muscle (MG) were observed on the full-wave rectified and averaged EMG record after 50 to 80 ms from the EMG onset of VL. No such EMG activity was observed in TA.
These results suggest that excitatory inputs including those of both descending and peripheral origin induced by voluntary contraction of Quad are responsible for facilitation of the ankle extensor and flexor motoneurons. In addition, removal of presynaptic inhibition of the Ia terminal of the motoneurons by descending motor command might explain the present results.View full abstractDownload PDF (1198K) -
MITSUGI MOTOYAMA, YOSHIYUKI SUNAMI, FUJIHISA KINOSHITA, TAKASHI IRIE, ...1994 Volume 43 Issue 4 Pages 300-308
Published: August 01, 1994
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSAfter a general clinical observation period of 3 months, men and women from 66-82 yr. of age with hypertension (n=10) were studied to assess the effects of long-term mild aerobic training and detraining on their blood pressure. Ten patients agreed to take part in aerobic training using a treadmill with the intensity at the lactate threshold (LT) for 30minutes 3-6 times a week for mean 17.1±9.8 months while the time course of changes in the resting blood pressure was monitored.
Following the training period the LT increased significantly by the end of the training period (P<0.001) . After 3months of training both the systolic and diastolic blood pressure decreased significantly (P<0.05, respectively) and both blood pressures stabilized at a significantly lower level throughout the remainder of the study. The mean blood pressure decreased significantly for 9 months (P<0.05) . Finally, the systolic, mean and diastolic blood pressure were found to have decreased significantly, by 9, 5, 11 mmHg, respectively by the end of the training period. (SBP and MBP: P<0.05, DBP: P<0.01, respectively) . One month after the training ended the systolic, mean and diastolic blood pressure all increased significantly (SBP and MBP: P<0.001, DBP: P<0.01, respectively) and approached the initial pre-training levels.
In conclusion, the antihypertensive effect of mild aerobic training at the LT was confirmed for older patients taking antihypertensive medications. However, the cessation of such training resulted in a quick return to pre-training levels.View full abstractDownload PDF (1082K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]1994 Volume 43 Issue 4 Pages 309-317
Published: August 01, 1994
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (4926K) -
1994 Volume 43 Issue 4 Pages 318-322
Published: August 01, 1994
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (754K)
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