手指最大肌力的力量變化速率與腦波之研究

本研究探討大腦神經活動對於手指進行最大收縮力量(maximal voluntary contraction，MVC)時，與三種不同力量變化速率下之關係。受試者為10名北部某大學學生，檢測無任何手部與腦部損傷，針對其手指的最大肌力進行三種不同力量速率的控制，要求受試者以右手食指分別依100、40、25(MVC/sec)的高、中、低三種力量變化率做最大力量的控制，各組均進行40次的施力，並要求減少力量曲線的誤差。受試者進行力量輸出同時戴上電極帽，透過多頻道腦波儀記錄蒐集三種不同力量變化率控制之腦波資料，分別就動作相關電位之準備期（動作前600至500ms）、開始期（動作前100ms至動作開始）、力量輸出前期（動作開始至500ms）與力量輸出後期（動作結束前500ms）四個成份分析。所得資料以平均數、二因子混合設計變異數分析（力量變化率與動作相關電位）進行統計考驗。結果發現在行為資料方面，力量曲線的誤差以高力量變化率最高，顯示力量控制的表現與力量變化速率的大小有關。腦波資料在四個不同動作的階段中，開始期與力量輸出前期對於力量變化率有顯著差異，顯示不同力量變化率與動作相關電位有高度的關係。就力量的速率而言，因動作的起始與結束過程中，力量輸出的加速度變化，與腦波資料呈現雙峰的現象不謀而合，表示大腦神經活動主要對於力量輸出時的速率高低變化有關。

關鍵字

手指；最大肌力；腦電波；力量變化率

並列摘要

This study discussed the cortical activation associated with the force outputs of index finger during maximal voluntary contraction (MVC) under different rate of force development. Subjects are 10 college students in Taiwan. All of them were right-handed with no history of neurological conditions or pathologies to either the hand or wrist. They were instructed to produce three different rates of force as accurate as possible to the MVC of index finger with high, middle and low rate of force development, 100 , 40 , 25 (MVC/Sec) respectively. They performed 40 trials for each task. We applied time-domain averaging of EEG single trials in order to extract four components of the movement-related cortical potentials (MRCP) preceding and accompanying force responses, which were the readiness potential (RP, -600 to -500 ms), motor potential (MP, -100 to 0 ms), first and second movement-monitoring potential (MMP1 & MMP2). The result found that the accuracy of the force trace was the highest in the high rate of force. It revealed that the accuracy of finger force contraction was related to rate of force development. In terms of EEG measures, we found a significant difference during MP and MMP1. Besides, the profiles of EEG showed a bimodal profile related to the acceleration of the initial and end of force contraction. It was coincided with the first derivative of force. It suggested that the cortical activation was a function of rate of force development during force production.

並列關鍵字

Finger ； Maximum voluntary contraction MVC ； Electroencephalogram EEG ； Rate of force development

參考文獻

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