Peak torque and electromyographic responses during fatiguing concentric muscle actions with eyes-open versus...

This study compared peak torque and electromyographic (EMG) mean frequency responses during fatiguing muscle actions with eyes-open vs eyes-closed. On four separate days, 21 men (M age = 23 yr.) performed 100 repeated maximal concentric muscle actions of the forearm flexors with eyes-open, eyes-closed, eyes-closed for first 50 muscle actions, and eyes-closed for the last 50 muscle actions while surface EMG signals were collected from the biceps brachii. The data were examined with seven separate repeated measures analyses of variance. There were no mean differences among the conditions for initial, average, and final peak torque, percent decline, the linear slope coefficient for the decline in peak torque, as well as the linear slope coefficient and y-intercept for the normalized EMG mean frequency vs repetition number relationships. These findings indicate performance during fatiguing muscle actions is not influenced by whether participants have their eyes open or closed throughout testing.