Study of the explosive strength of the rectus femoris muscle using electromyography.

The rectus femoris muscle was electromyographically studied in eleven individuals of the masculine sex. The objective was to study the action potential and the explosive strength of this particular muscle in the movement utilized to kick the field soccer ball and in other exercises of the orthostatic position. The following movements were analyzed: flexibility of the hip with the knee bent, flexibility and extension of the knee (completely crouched), flexibility of the hip with the knee extended, movement of the kick without contact with the ball and movement of the kick in contact with the ball. The results were: the rectus femoris muscle showed much stronger action potential in flexing the hip with the knee flexed more than 90 degrees; with the knee extended 60 to 90 degrees; in the movement extending the knee from a complete crouch and at the moment of the kick in contact with the ball. The action potential was strong in the movements flexing the knee (crouch) and in the initial movement of the kick.