The cause of shoulder disorders of juvenile baseball pitchers by analyzing shoulder girdle motion
| Project/Area Number |
17500445
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Sports science
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| Research Institution | Chukyo University |
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Principal Investigator |
SHIMIZU Takuya (2006) Chukyo University, School of Health and Sport Sciences, Professor, 体育学部, 教授 (60273223)
桜井 伸二 (2005) 中京大学, 体育学部, 教授 (20144173)
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| Co-Investigator(Kenkyū-buntansha) |
清水 卓也 中京大学, 体育学部, 教授 (60273223)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2006: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2005: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | landmark / magnetic sensor / DLT method / restriction of internal rotation / laxity / baseball shoulder / juvenile / baseball / 体表マーカー / 内旋制限 / 肩甲骨 / 上肢帯 / コッキング / 加速期 / 赤外線3次元動作解析装置 |
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| Research Abstract |
We measured the position of the anatomical landmarks of the scapular and humerus by use of an optical motion capture system at 25 selected positions (5 elevation planes and 5 elevation angles) of the upper arm and estimated changes of the scapulohumeral angle during the dynamic upperarm elevation by the regression equation, and compared with data obtained by use of an electromagnetic sensor which were set as standard values. The estimated scapular internal rotation and upward rotation values matched well with those measured by electromagnetic sensor when the humeral horizontal adduction angle was above 30°. A systematic error was observed between the estimated values and the data obtained from the electromagnetic sensor when the humeral adduction angle was less than 30°. The scapular tilt could not be estimated with accuracy. The present model can reasonably predict scapular upward rotation and internal rotation angles.
We had medical check on shoulders of forty juvenile baseball players (av. 12.3 years). External rotation of the first position of the dominant side was significantly greater than that of the non-dominant side. Nine players who had positive sulcus signs on either dominant or non-dominant side had significantly less internal rotation of the third position than the other players. Whereas the eighteen players who had positive posterior laxity on either dominant or non-dominant side didn't have significantly less internal rotation of the third position than the other players. Positive sulcus sign suggests inferior laxity. This means inferior laxity has different role on developing posterior tightness of the throwing shoulder from posterior laxity.
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Report
(3 results)
Research Products
(6 results)
