Japanese Journal of Physical Fitness and Sports Medicine
Online ISSN : 1881-4751
Print ISSN : 0039-906X
ISSN-L : 0039-906X
Volume 53, Issue 2
Displaying 1-10 of 10 articles from this issue
  • CHIKAKO HAYASHI, MIZUNE IKEDA, KATSUJI AIZAWA, FUMIE MURAI, NOBORU MES ...
    2004 Volume 53 Issue 2 Pages 197-203
    Published: April 01, 2004
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The purpose of this study was to evaluate the change in dynamic and static balance ability during the menstrual cycle among young women. The subjects were young healthy women (n=12, age 20.4±1.2 years) with regular exercise and a normal menstrual cycle. The menstrual cycle was divided into 5 phases : Menstrual, Follicular, Ovulatory, Early luteal and Late luteal. Measurements were taken using the dynamic balance test, static balance test and looseness test. The dynamic balance test did not change during the menstrual cycle. Length Time within the static balance test increased in the late luteal phase compared to other menstrual cycle phases. The deviation of the mean of X within the static balance test increased in the follicular and late luteal phase and decreased in the ovulatory phase. Also, the deviation of the mean of X increased in the follicular phase compared to the menstrual phase and decreased in the menstrual and early luteal phases compared to the follicular and ovulatory. Left arm upper of laxity in hand on the back test within looseness test increased in the menstrual and early luteal phases compared to other menstrual cycle phases. These results suggest that static balance ability changes during the menstrual cycle.
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  • YOSHIKI KAMIYAMA, TAKESHI KAWAGUCHI, AKIRA KANDA, SHINYA KUNO, TAKAHIK ...
    2004 Volume 53 Issue 2 Pages 205-209
    Published: April 01, 2004
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    In order to study the effect of muscle exercise on the medical expenditure of the elderly, a three-year exercise program focusing on muscle activity was performed by an intervention group. Individual yearly medical expenditures were collected by 20 participants of the exercise group aver aging 65.2 years of age and 23 control subjects averaging 68.4 years of age with National Health Insurance coverage. Yearly medical expenditures for the exercise group were significantly lower than those of the control group at one and two years after entry. The expenditures increased by 62.6% from 1997 to 1999 in the control group, whereas they increased by only 16.8% for the exer cise group. The results suggest the possibility of the effectiveness of muscle exercise on the reduction in medical expenditure among the elderly.
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  • TAKASHI ENDOH, MASASHI MITAMURA, TSUYOSHI NAKAJIMA, REI TAKAHASHI, TOM ...
    2004 Volume 53 Issue 2 Pages 211-220
    Published: April 01, 2004
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The present study investigated how resistance training affects behaviors related to central and peripheral fatigue during a sustained maximal voluntary contraction (MVC) . The subjects were well-trained (TR, n=8) and sedentary untrained (UT, n=6) males. The subjects were asked to repetitively perform 3 sets of MVC (elbow flexion) for 1 min with a rest interval of 1 min. Transcranial magnetic stimulation (TMS) was delivered to the contralateral motor cortex to evoke the motor evoked potential (MEP) and electromyographic (EMG) silent period (SP) after the MEP. Ratio of root mean square (RMS) of the EMG and elbow flexion force (RMS/F) was also calculated.
    The time course of the decrease in elbow flexion force that was standardized with respect to the maximal value obtained at the beginning of the first MVC was almost identical in both TR and UT. At the end of the task, the elbow flexion force decreased to around 30 % of the initial value in both groups. Decrease in voluntary activation (VA) estimated by the increment of the force after TMS was significantly larger in UT (77.3%) than in TR (88.2%) at the end of the task. Although the increase in MEP during the first set was significantly greater in UT than in TR, elongation of SP was significantly larger in UT than in TR. Increase in RMS/F, which is a manifestation of peripheral fatigue, was significantly larger in TR than in UT.
    These results suggest that decrease in MVC in UT and in TR is respectively more attributable to central and peripheral fatigue, and that inhibitory inputs to motor cortex were larger in UT than in TR. It is concluded that expression of central and peripheral fatigue is affected by resistance training.
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  • HIDENORI AKAHA, KAZUO AOKI, HIDETOSHI HOSHIKAWA
    2004 Volume 53 Issue 2 Pages 221-234
    Published: April 01, 2004
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The purpose of this study was to examine the effects of ankle plantar and dorsal flexion on the lower extremities' dynamics and crank torque in pedaling movements. Twelve males (6 cyclists and 6 non-cyclists) pedaled at the rate of 90 and 120 rpm for a power output of 200W. Subjects were divided into two groups according to the different ankle movement patterns in one crank rotation. The first group (Gr1) showed a one time plantar and dorsal flexion movement in one rotation. The second group (Gr2) showed two plantar and dorsal flexion movements in one rotation. It was assumed that the exertion of positive plantar flexor power in the upstroke phase could provide the difference of the ankle movement patterns. The following results were shown in Gr2 as compared with Grl. 1) The positive crank torque time ratio was extended due to dorsal flexor torque produced near the top dead center. 2) Continuous muscle contraction of the same muscle was avoided and reduction in a burden was brought about due to plantar flexion in the upstroke phase. 3) Reduction of hip extensor torque was shown. These results suggest that two dorsal and plantar flexion movements in one rotation in pedaling could be a more effective pattern in terms of muscle work.
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  • YUKIO TANAKA, KAZUMI EGUCHI, TAKASHI ITO, TAKASHI TAKEMIYA
    2004 Volume 53 Issue 2 Pages 235-244
    Published: April 01, 2004
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The purpose of this study was to investigate the differences and effects of positional loading (arm position change) and image loading in Budo (martial arts) competitors, mainly kendo (Japanese fencing) masters. The microcirculatory responses were measured by differential digital photoplethys-mography (ΔDPG) using the characteristics of Budo mental attitude, experience and skill as para-meters.
    The subjects were 7 kendo masters of the fifth grade or higher with mean experience of 29 years, 7 kendo athletes, 7 kyudo (Japanese archery) athletes, 5 karate athletes in university sports clubs and 9 middle-aged controls. Positional loading induced myogenic responses and image loading for examining sympathetic effects via the central nervous system on peripheral circulation were mea-sured in the subjects at rest in a sitting position. The following results were obtained
    The increase in the . ΔPG-P wave height in response to positional loading was markedly larger in the kendo masters. In particular, the increase when raising the right arm was significantly higher in the kendo masters than in the kyudo and karate athletes (P<0.05) . The decrease in the ΔDPG-P wave height when lowering the right arm was smallest in the kendo masters. There were differences in the peripheral vascular responses between kinds of Budo and levels of skill, which were induced by differences at the time of arm raising.
    The DPG-P wave height was significantly lower during stress imaging than before loading in all subjects. The effect of stress imaging was smallest in the kendo masters, and markedly large in the kyudo athletes (P<0.05) . During relaxation imaging, an increase in the ΔDPG-P wave height was observed in the kendo masters alone, and the occurrence of vascular dilation was confirmed.
    These results suggest that arteriolar responses of kendo masters are flexible and stable despite their long training period ; and the control and regulation of muscle vascular tone is well-maintained via the central nerve-sympathetic and myogenic coupling.
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  • DAISUKE SHIVA, HIROSHI AMAOKA, HIROMI MATSUZAKI, KAZUHIKO KIMURA, HIRO ...
    2004 Volume 53 Issue 2 Pages 245-254
    Published: April 01, 2004
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    To clarify the recovery patterns of spontaneous activity and liver damage after different stressors, female Fischer 344 rats were treated with Propionibacterium aches (P, aches) or water immersion stress before lipopolysaccharide (LPS) injection. They were then examined for wheel running activity, serum corticosterone concentration, serum alanine aminotransferase (ALT) activity, histological appearance of liver and plasma tumor necrosis factor alpha (TNF-a) concentration.
    The recovery in physical activity of P. aches-treated rats was faster than that of water immersion rats. One day after the stressors, serum corticosterone cancentration and ALT activity of P. acnes-treated rats were higher than that of water immersion rats. In addition, increases in serum ALT activity and plasma TNF- a, as well as massive necrosis of the liver in P. acnes-treated rats were observed seven days after stress treatment. The P. acnes-LPS rats also showed a reduction in survival rate after 24 hours. These results suggest that P. acnes stress causes serious inflammation when stimulated by LPS. Although rapid recovery in physical activity was not inhibited by P. acnes stress, it differed from the response of water immersion stress.
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  • TETSUJI KAKIYAMA, ATSURO KUSHIMA, AKIRA HIROTA
    2004 Volume 53 Issue 2 Pages 255-262
    Published: April 01, 2004
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    We carried out tests of visual functions and evaluated the effects of the correction of visual acuity on kinetic visual acuity (KVA) in 21 high school rugby players. KVA during sports activities was highly correlated with binocular vision (r=0.719, p<0.0001) and static visual acuity (SVA) (r =0.798, p<0.0001) . When binocular vision, SVA, and KVA during sports activities were compared after correction, they all significantly improved after correction (binocular vision: 0.78±0.39→1.46 ±0.26, p<0.0001 ; SVA : 0.86±0.48→1.31±0.25, p<0.01 ; KVA : 0.54±0.350.75±0.20, p <0.05) . Moreover, significant negative correlations were observed among binocular vision, SVA, and KVA and the percent improvement after correction (r=-0.755, r=-0.848, r=-0.829, respectively ; all p<0.001) . The percentage of KVA to SVA was 64.0±21.7% during sports activities and 59.1±16.7% after correction decreasing slightly with correction, though not significantly. Therefore, KVA, which plays an important role in sports activities, improved as SVA improved, and poor KVA is thought to improve to an adequate level by correction of visual acuity. However, the effect of a correction was smaller in KVA than in SVA, and KVA deteriorated with over-correction in some players. Further studies are needed concerning the criteria for correction to obtain good KVA and the relationship between correction and training.
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  • 2004 Volume 53 Issue 2 Pages 263-266
    Published: April 01, 2004
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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  • 2004 Volume 53 Issue 2 Pages 267-271
    Published: April 01, 2004
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    Download PDF (812K)
  • 2004 Volume 53 Issue 2 Pages 272-278
    Published: April 01, 2004
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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