Japanese Journal of Physical Fitness and Sports Medicine
Online ISSN : 1881-4751
Print ISSN : 0039-906X
ISSN-L : 0039-906X
Volume 63, Issue 2
Displaying 1-6 of 6 articles from this issue
Review
  • Satoshi Kurihara, Masato Suzuki, Hiroshi Kiyota
    2014 Volume 63 Issue 2 Pages 247-257
    Published: April 01, 2014
    Released on J-STAGE: March 20, 2014
    JOURNAL FREE ACCESS
    Kanehiro Takaki, the founder of The Jikei University School of Medicine suggested that a nutritional factor was important for preventing beri-beri, which was a common disease in the Meiji era in Japan and Southeast Asia. He improved the rations fed to crews of the Imperial Japanese Navy to include wheat and meat. The rations he devised effectively prevented beri-beri. Some 30 years later, vitamin B1 was discovered, and a deficiency of vitamin B1 was found to be the cause of beri-beri. Takaki believed that nutrition and exercise were important for keeping our bodies fit. He often gave lectures on how people could keep fit to prevent diseases. Thus, his activities are considered to be the beginning of preventive medicine in Japan. The contributions of Takaki to the physical fitness of the Japanese people have been continued by the graduates of The Jikei University School of Medicine. Some of the graduates became professors of The Jikei University School of Medicine and Tokyo University of Education (now, Tsukuba University). Thus, both universities have the common basis and tradition for research and education in the fields of physical fitness and sports medicine, and have collaborated with each other in these fields. In this article, we provide a brief overview of the history of the development of research regarding physical fitness and sports medicine in Japan. We discuss the contribution of various persons including our graduates, to the health and physical fitness of the Japanese people.
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Original
  • Mami Yanagawa, Yoshiyasu Higuchi, Takeshi Matsubara, Makoto Numata, Ki ...
    2014 Volume 63 Issue 2 Pages 259-267
    Published: April 01, 2014
    Released on J-STAGE: March 20, 2014
    JOURNAL FREE ACCESS
    Evidence suggests that sports activity can induce site-specific changes in bone mineral content (BMC) in athletes. Therefore, the first purpose of this study was to create a standard value for BMC (SVBMC) that is independent of body size and physical exercise effect. The second purpose was to examine usefulness for the SVBMC. In creating the SVBMC, we recruited non-customer subjects who engaged in regular exercise but did not have site-specific changes to their bony structure. We studied 285 females (34.0±6.5 years) that were currently active, free from hormone treatment, and were not taking medication for any condition. Furthermore, all female subjects reported having a normal menstrual cycle. Bone area (BA), BMC and areal bone mineral density (aBMD) were measured by dual-energy X-ray absorption. Measurements of almost the complete skeleton, with the exception of the head, were taken (herein referred to as sub-total). This included scans of the entire spinal column, all 12 ribs, pelvis, full legs and arms. An allometry formula that relates BMC and BA was applied to determine the SVBMC. To exclude the effect of body size, calculations were determined using the perpendicular distance from the data of each individual to that determined by allometry regression. Finally, the mean and standard deviation of the distance were converted into T-scores. In examination of reliability for the SVBMC, we calculated the SVBMC for three customer females who engaged in regular exercise. We found a significantly positive relationship between SVBMC and weight/BMI. This correlation was weaker than the relationship between SVBMC and BMC, as expected, or the relationship between SVBMC and aBMD, with the exception of SVBMC in the pelvis. In conclusion, this study suggests that SVBMC is less affected by body size than by BMC or aBMD and the SVBMC was provided highly useful in case study.
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  • Hayato Ohnuma, Yuichi Hirano, Masanobu Tachi
    2014 Volume 63 Issue 2 Pages 269-278
    Published: April 01, 2014
    Released on J-STAGE: March 20, 2014
    JOURNAL FREE ACCESS
    The purpose of this study was to clarify the changes of left and right leg movement on curved path during the latter half of 400m sprint. Subjects were 8 male university sprinters (age 20.0 ± 1.2, height 1.75 ± 0.07m, weight 64.7 ± 6.2kg, personal best for 400m 50.98 ± 2.36sec). The subjects performed 400m sprint with maximal effort on the 1st lane in outdoor track. Trials were recorded and analyzed by two-dimensional motion analysis method focusing on 160-360m section during 400m sprint. This section was divided into five 40m phases (In straight , Beginning of curve, Center of curve, End of curve, and Out straight). The kinematics parameters were averaged for each phase and compared between the phases and between the left and right legs. The running velocity and the step frequency decreased significantly after the Center of curve in both legs. The stance time and the flight time increased significantly after the Center of curve in left leg and the right leg, respectively. Although, the step length of the left leg decreased significantly after the End of curve, the right leg showed no significant difference. Also, the stance distance of the left leg decreased significantly after the End of curve. Form these results, the present study demonstrated that the changes of movement and the factors affecting the decline in running velocity are different between left and right legs on curved path during the latter half of 400m sprint.
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  • Gou Hayata, Takeshi Miyakawa
    2014 Volume 63 Issue 2 Pages 279-285
    Published: April 01, 2014
    Released on J-STAGE: March 20, 2014
    JOURNAL FREE ACCESS
    The purpose of this study is to show the kinetic effect on the stop-jump movement in wearing overlap length change of the knee joint supporter. Ten young health males volunteered as subjects for this study. Three-dimensional videographic and ground reaction force data in a stop-jump task were collected in three conditions. Overlap length of supporter, peak ground reaction force, peak knee flexion angle, peak knee extension torque at landing, peak jump height, peak jump velocity at takeoff were compared among conditions: high pressure condition, middle pressure condition and no supporter. The high pressure condition significantly increased peak knee flexion angle and peak knee extension torque at landing. It is considered that the high pressure condition enlarged the knee joint angle and the knee joint extension torque in stop task because the rigidity of the supporter increased. On the other hand, it was suggested that the pressure change of wearing the knee joint supporter don’t affect jump performance.
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