1997 Fiscal Year Final Research Report Summary
Effect of pedaling speed and load on EMG activity of biarticular muscles in thigh portion
| Project/Area Number |
07680138
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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 | Juntendo University |
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Principal Investigator |
KATAMOTO Shizuo Juntendo University Shool of Health and Sports Science, Associate Professor, スポーツ健康科学部, 助教授 (50053343)
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| Project Period (FY) |
1995 – 1997
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| Keywords | power output / strength type and speed type / pedaling / EMG / two joint muscle |
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| Research Abstract |
The purpose of this study was to examine the effect of pedaling speed and load on EMG activity of biarticular muscles in thigh portion, and to clariy the characteristics of EMG activity in relation to "strength type" and "speed type" of power output. Eleven collegiate men were asked to perform bicycle ergometer exercise at power outputs of 2.5, 3.5, 4.5, 5.5 and 6.5W/kg by constant pedaling speed (60rpm) and various pedaling speed (50, 70, 90, 110 and 130rpm) . During each pedaling exercise, surface EMG activities were recorded from right M.vastus lateralis, rectus femoris, biceps femoris caput breve and biceps femoris caput longum, The subjects were also asked to perform 4 supramaximal pedaling exercsie at loads of 5, 7.5, 10, and 12.5% of their body weight for 8sec to measure their maximal anaerobic power output and then they were classified into strength type or speed type group in relation to their power output characteristics. By increasing pedaling speed and load, IEMG/sec in all muscles studied were increased linealy. IEMG/W kg^<-1> of single articular muscles was decreased with incresing pedaling torque, but that of biarticular muscles was unchanged. On the other hand, increase of pedaling speed induced the decrease of IEMG/W kg^<-1> in biarticular muscles and no change in IEMG activities of sigle articular muscles. However, these tendency found in EMG activities were dependent on the type for power output. In speed type group, it was showed that IEMG/W kg^<-1> in M.rectus femoris and biceps femoris caput breve were decreased with increasing pedaling speed. From these results, it was suggested that by increasing pedaling speed, activity of biarticular muscles of thigh portion could be inhibited, and activities of rectus femoris and biceps femoris caput breve woud be responsible for development of speed type for anaerobic power output.
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