@article{oai:nsg.repo.nii.ac.jp:00004101,
 author = {岩部, 達也 and 大西, 秀明 and 久保, 雅義 and 古川, 勝弥 and 桐本, 光 and Iwabe, Tatsuya and Onishi, Hideaki and Kubo, Masayoshi and Furukawa, Katsuya and Kirimoto, Hikari},
 issue = {1},
 journal = {理学療法学, 0289-3770},
 month = {Feb},
 note = {application/pdf, 論文(Article), 【目的】筋疲労課題中における筋力,筋活動および大脳皮質感覚運動野領域の活動の時間的変化を明らかにすることである。【対象および方法】対象は健常男性成人7名とした。筋疲労課題は,最大収縮の50%(50%MVC)での右手指把持300秒間持続と,最大収縮(100%MVC)での右手指把持120秒間持続の2条件とした。両条件において,120秒間の安静の後に課題を遂行し,課題終了後300秒間の安静時間を設けた。安静時および課題遂行中の大脳皮質酸素化ヘモグロビン変化量(⊿oxyHb)を近赤外分光イメージング装置(fNIRS)を用いて計測した。また,把持力および筋電図を併せて記録した。【結果】両条件下において,把持開始後直ちに⊿oxyHbの増加がみられたが,50%MVCでは把持力および筋活動の低下の後に時間をおいて⊿oxyHbの緩やかな減少が認められ,100%MVCでは,把持力および筋活動が低下しているにも関わらず課題終了間近まで⊿oxyHbの増加が認められた。両条件における⊿oxyHbの減衰率は,筋電図の減衰率に比べ少なかった。【結論】負荷量の異なる疲労課題において,筋活動が低下しているにも関わらず,感覚運動野領域の活動は最大収縮条件で増加し続け,最大下収縮条件では増加後に低下することが明らかとなった。, Purpose: We investigated the relationships of changes among muscle forces, muscle activities and sensorimotor cortical activity during exhaustive task. Subject and Method: Seven male healthy subjects participated in this experiment. Subjects performed handgrip task with maximul voluntary contraction (100%MVC) for 120s and with 50% maximal contraction (50%MVC) for 300s. The rest period was given berore (120s) and after (300s) the task. The cerebral cortex oxy-hemoglobin concentration change (⊿oxyHb) was measured by Near-infrared spectroscopy (NIRS) from the beginning of the first rest period to end of the second rest period. Muscle force and electromyogram were also measured in the same period. Result: In both conditions, ⊿oxyHb in sensorimotor cortex exhibited steady increases in initial part of the handgrip task. In 50%MVC condition, the decrease of ⊿oxyHb was preceded by the decrease in muscle force and muscle activity. However, In 100%MVC condition, the decrease of ⊿oxyHb was observed only at the end of the hand grip task. In both conditions, reduction rates of Purpose: We investigated the relationships of changes among muscle forces, muscle activities and sensorimotor cortical activity during exhaustive task. Subject and Method: Seven male healthy subjects participated in this experiment. Subjects performed handgrip task with maximul voluntary contraction (100%MVC) for 120s and with 50% maximal contraction (50%MVC) for 300s. The rest period was given berore (120s) and after (300s) the task. The cerebral cortex oxy-hemoglobin concentration change (⊿oxyHb) was measured by Near-infrared spectroscopy (NIRS) from the beginning of the first rest period to end of the second rest period. Muscle force and electromyogram were also measured in the same period. Result: In both conditions, ⊿oxyHb in sensorimotor cortex exhibited steady increases in initial part of the handgrip task. In 50%MVC condition, the decrease of ⊿oxyHb was preceded by the decrease in muscle force and muscle activity. However, In 100%MVC condition, the decrease of ⊿oxyHb was observed only at the end of the hand grip task. In both conditions, reduction rates of ⊿oxyHb were less than that of the muscle activities. Conclusion: This study demonstrated that in 100%MVC condition, sensorimotor cortical activity keeps increasing even though muscle activity starts decreasing due to fatigue. However, in 50%MVC condition, decrease in senserimotor cortical activity is observed significantly later then the occurrence of the in muscle activity.⊿oxyHb were less than that of the muscle activities. Conclusion: This study demonstrated that in 100%MVC condition, sensorimotor cortical activity keeps increasing even though muscle activity starts decreasing due to fatigue. However, in 50%MVC condition, decrease in senserimotor cortical activity is observed significantly later then the occurrence of the in muscle activity.},
 pages = {35--40},
 title = {筋疲労課題中における大脳皮質感覚運動野領域のヘモグロビン濃度変化について : 近赤外分光イメージング装置による検討},
 volume = {37},
 year = {2010}
}