2004 Fiscal Year Final Research Report Summary
Changes in circulatory dynamics of upper extremity and saccadic reaction time during neck flexion
| Project/Area Number |
14580050
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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 |
体育学
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| Research Institution | Osaka City University |
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Principal Investigator |
WATANABE Hitoshi Osaka City University, Institute for Health and Sport Sciences, Associate Professor, 体育学研究室, 助教授 (50167160)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIWARA Katsuo Kanazawa University, Department of Human Movement and Health, Graduate School of Medical Science, Professor, 大学院・医学系研究科, 教授 (60190089)
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| Project Period (FY) |
2002 – 2004
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| Keywords | Neck flexion0 / Saccadic reaction time / Near-infrared spectroscopy / Muscle oxygenation / Vasodilatation / Muscle sympathetic nerve activity / Circulatory dynamics / Brain activation |
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| Research Abstract |
The present study investigated changes in circulatory dynamics of upper extremity muscles during a task involving maintaining neck flexion and during the neck flexion task accompanied with an eye movement reaction task. Neck flexion angles were randomly set at 0°, 10° and 20°. Muscle oxygenation in the biceps brachii and triceps brachii, skin blood flow over the muscles, electrocardiograms, blood pressure and cardiac output were measured during both tasks. Furthermore, muscle sympathetic nerve activity (MSNA) was recorded from peroneal nerve during the neck flexion. During the neck flexion task, oxygenation in muscles increased significantly with angle of neck flexion. Oxygenation in muscles tended to be larger in the neck flexion task with the eye movement reaction task than in the neck flexion task alone. A significant difference between tasks was found at 20° flexion. Furthermore, skin blood flow over the biceps brachii tended to be smaller under the combined task than under the neck flexion task alone. A significant difference between tasks was found at 20° flexion. No significant task effects were found in electrocardiograms, blood pressure or cardiac output. Blood flow within upper extremity muscles was clearly increased while maintaining neck flexion. Blood flow increased more when the neck-flexion task accompanied the eye movement reaction task. MSNA was tendency to decrease during neck flexion. This suggests that brain activation associated with maintaining neck flexion influences the vasomotor center in the medulla oblongata controlling circulatory responses, leading to vasodilatation in muscles. Furthermore, additional brain activation appears to offer synergistic effects during the combined neck flexion and eye movement reaction tasks, and reduction of skin blood flow by skin vasoconstriction might be related to increased blood flow in addition to vasodilatation in muscles.
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