- 著者
- Yohei Tomaru Hiroshi Kamada Yuta Tsukagoshi Shogo Nakagawa Mio Onishi Kenta Tanaka Ryoko Takeuchi Yuki Mataki Shumpei Miyakawa Masashi Yamazaki
- 出版者
- THE JAPANESE ASSOCIATION OF RURAL MEDICINE
- 雑誌
- Journal of Rural Medicine (ISSN:1880487X)
- 巻号頁・発行日
- vol.14, no.2, pp.176-180, 2019 (Released:2019-11-20)
- 参考文献数
- 10
- 被引用文献数
- 2
Objectives: The purpose of this study was to evaluate the relationship between exercise time and musculoskeletal problems and to determine the appropriate amount of exercise for children in both lower- and higher-grade levels of elementary and junior high schools.Materials and Methods: Mark-sheet-type questionnaires were distributed to and collected from all elementary and junior high schools in two cities. We collected 22,494 questionnaires in total. The relationship between exercise time and musculoskeletal problems was analyzed. The χ2 test and multivariate logistic regression analysis were used for statistical analyses.Results: The mean exercise time in school, in addition to physical education time, was 3.1 hours per week. In 56% of the children, the exercise time was less than 2 hours per week, and in 13% of the children, the exercise time was more than 10 hours per week. Although the rate of sports injury increased with an increase in exercise time, the duration of one-leg stand (a test of balance and muscle strength) also increased with an increase in exercise time. The cut-off values for sports injuries in boys/girls were 2.9/2.9 hours, 4.0/2.9 hours, and 7.5/4.2 hours in lower grade elementary school, higher grade elementary school, and junior high school, respectively.Conclusions: Although an appropriate amount of exercise improves one’s physical health and ability, excessive exercise leads to musculoskeletal problems. Approximately 7 hours/week of exercise is recommended for junior high school students. In elementary school, the exercise time should be carefully decided as the musculoskeletal system of the students is still immature.
- 著者
- Yasushi Matsui Shoji Takayanagi Takuya Ohira Masahiro Watanabe Hiroki Murano Yasufumi Furuhata Shumpei Miyakawa
- 出版者
- The Society of Physical Therapy Science
- 雑誌
- Journal of Physical Therapy Science (ISSN:09155287)
- 巻号頁・発行日
- vol.31, no.1, pp.95-101, 2019 (Released:2019-01-29)
- 参考文献数
- 42
- 被引用文献数
- 3 7
[Purpose] The aim of this study was to determine whether the consumption of a leucine-enriched essential amino acid mixture (LEAA), which is known to increase protein synthesis in muscles, alleviates muscle damage and accelerates recovery by ameliorating muscle damage. [Participants and Methods] A double-blind, randomized crossover trial was conducted over a 5-week period. Ten untrained males (age, 23.0 ± 1.6 years) were asked to repeatedly flex and extend their elbows for 10 counts/set × 5 sets at full power while using a dynamometer. The participants took 3.6-g supplements (LEAA mixture or placebo) 3 times daily on day 0 and for the next 7 days. Changes in serum creatine phosphokinase (CPK) activity and myoglobin concentration as markers of muscle tissue damage were evaluated prior to and after exercise and on days 1, 2, 3, 5, and 7. [Results] The relative ratio of the changes in peak serum CPK activity measured on day 5 was significantly lower after taking LEAA than after taking the placebo. [Conclusion] LEAA consumption suppressed exercise-induced elevation of muscle damage markers in blood, which suggests that LEAA could attenuate muscle damage and aid muscle recovery.
- 著者
- Keita Suzuki Satoshi Nagai Ryo Ogaki Koichi Iwai Takuo Furukawa Shumpei Miyakawa Masahiro Takemura
- 出版者
- The Japanese Society of Physical Fitness and Sports Medicine
- 雑誌
- The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)
- 巻号頁・発行日
- vol.8, no.2, pp.79-88, 2019-03-25 (Released:2019-03-16)
- 参考文献数
- 28
- 被引用文献数
- 3
The purpose of this study was to clarify the tackling characteristics of tacklers relationship causing concussion based on match video records in the collegiate rugby union. Twenty-three tackling situations leading to concussion were identified based on injury data and video records. Additionally, 94 tackling situations in which concussion did not occur were extracted from the same matches. Overall, one hundred and seventeen tackling situations were analyzed in detail, and categorized into three tackle phases and outcomes. Logistic regression analysis was performed to clarify which tackling characteristics in the tackler relationship had a higher chance of concussion. The chance of concussion occurring to a tackler was significantly higher for collision tackle (odds ratio [OR] 84.00, 95% CI 8.27–853.11), making initial contact with tackler’s head/neck (OR 23.47, 95% CI 4.80–114.71), no arm usage by tackler (OR 3.54, 95% CI 1.23–10.20) and tackle break by ball-carrier (OR 5.76, 95% CI 1.67–19.85). Conversely, tacklers were significantly less likely to suffer concussion when the ball-carrier performed a side step before initial contact (OR 0.11, 95% CI 0.01–0.85). In conclusion, tackles leading to concussion were related to various factors in the time period before and after tackle as well as in the moment of tackle. The results of this study suggest that further research needs to be done, given the relationship between each tackling characteristic. Moreover, we consider that players and coaching staff should improve tackle skill safety by clarifying the common contributing factors to both suffering concussion and tackle performance.
- 著者
- Satoshi SHIBATA Masahiro TAKEMURA Shumpei MIYAKAWA
- 出版者
- Japanese Society of Physical Therapy
- 雑誌
- Physical Therapy Research (ISSN:21898448)
- 巻号頁・発行日
- vol.21, no.2, pp.44-52, 2018-12-20 (Released:2018-12-20)
- 参考文献数
- 44
- 被引用文献数
- 14
Background: Neurocognitive function may be a risk factor for anterior cruciate ligament (ACL) injury by changing neuromuscular control such as muscle activities. However, the effect of differences in neurocognitive function on biomechanics and neuromuscular control related to ACL injury risk is not clear. The purpose of this study was to examine the effect of differences in neurocognitive function on biomechanics and neuromuscular control during an unanticipated side-step cutting motion. Method: The subjects were 15 collegiate female athletes who were divided into two groups using the Symbol Digit Modalities Test (SDMT). The experimental task was an unanticipated side-step cutting motion from a 30 cm high box. We calculated joint angles and moments using a 3-dimensional motion analysis system from the dominant leg, and measured muscle activities using a surface electromyography. We calculated the co-contraction ratio (CCR) as relative muscle activity of the quadriceps to the hamstring. Results: As a result, subjects with a lower SDMT score had significantly increased quadriceps activity before and after ground contact and decreased CCR only after ground contact. Conclusion: In the lower SDMT score group, the quadriceps showed stronger muscle activity than the hamstring during an unanticipated side-step cutting motion. This dominant quadriceps muscle activity has been reported to increase the load on the ACL, and there was a possibility of increasing the risk of the ACL injury. Considering these factors, subjects with lower neurocognitive function could have a high risk of ACL injury due to alterations in muscle activities surrounding the knee.