表面筋電図法を用いた力の調節の評価法開発

A new strategy on evaluation of the force control, using the force rate and the amplitude of surface-electromyogram

要旨：道具の操作能力評価法の開発には，力の調節能力(追従能力と筋活動能力)を明らかにする必要がある，目的は，標的筋力追従課題を左右の手で行わせ，力と表面筋電位振幅(包絡線)との関係，異なる出力率間での力の調節，力の調節のうまさを明らかにすることである．方法は，右利きの女性健常成人16名に，等尺性収縮の示指外転力にて5秒間で目標値(10，20，40，60％MVC)に到る，異なる出力率にて標的を追従させた．結果，左右差は見られなかったが，力と筋電位は比例関係であり，異なる出力率間での力の調節は40％MVCまでと60％MVCでは異なる傾向を示した．以上の傾向より本評価方法にて力の調節能力を評価できる可能性が示唆された．

　The purpose of this study was to investigate the pursuit ability of force and the relationships between the force rate and the amplitude of a surface electromyogram for a new evaluation method of the force control, when using a tracking paradigm. In sixteen right handed females, the EMG was recorded from the first dorsal interosseus (FDI) muscle of both hands while subjects isometrically abducted the index finger against a force transducer. The subjects were asked to increase linearly the contraction with each hand at different force rates, i.e., from 0 to 10, 20, 40, and 60 %MVC levels, respectively, in 5 sec, pursuing a target force displayed on the CRT. For the linearly increasing (RAMP), the slope of the linear regression and the coefficient of determination were calculated for the normalized EMG and force level. Results were as follows; 1) the different force rates did not influence the pursuit ability and 2) the relationship's slope of the regression line between target load and %EMG were quasi linear. These findings suggest that this relationship might be valuable for the evaluation of the force control, if more data were to be collected. Further studies will be needed.