이기영(Kiyoung Lee) ; 장지훈(Jihoon Jang) ; 원종칠(Jongchil Won) ; 이근용(Keunyong Lee) ; 엄혁주(Hyokju Eum) ; 이상식(Sangsik Lee)
Despite of muscle group and posture variability; regression model to estimate endurance time have mainly developed by using the percentage of maximum voluntary contraction (%MVC). This paper presented two regression models by using the relative load intensity %MVC and the relative gravitational torque ratio %GTR (gravitational torque ratio) as a prediction variable for the biceps brachii muscle; and compared these models with the existing models. Sixty volunteers (30 females; 30 males) participated in this study; and performed isometric contraction exercises at 6 relative load intensities from 30% to 80% of MVC increasing by 10%; respectively; until their exhaustion to determine endurance times. Two regression models were induced from two relations between the measured endurance times and %MVC and between those and %GTR; and compared with the existing models by their correlation; determinant coefficients (r2) and mean square errors (MSE). The results demonstrated that the presented models were valid to estimate muscle endurance time by using %GTR of the biceps brachii muscle.