Electromyographic assessment of quadriceps muscle group during knee extension with weighted boot
An electromyographic study was conducted using three superficial quadriceps muscles in a knee extension progressive resistance exercise from 90 degrees to 180 degrees with a weighted boot. Continuous recordings were taken on five females and five males in the pre- exercise position with the knee at 90 degrees, during the exercise, and in the post-exercise position. It was found that the greatest muscle action potentials were produced by the rectus femoris and that the vastus lateralis and vastus medialis exhibited similar action potentials throughout the exercise. All subjects demonstrated increased muscle action potentials within the exercise bout as the gravitational torque increased and between exercise bouts with additional weight increments. No amplitude in muscle action potentials were recorded from die muscles during the pre-exercise and post-exercise positions in which the leg was hanging freely with suspension weights up to 24.13 kilograms attached. This finding suggested viscoelastic connective tissues were supporting the downward gravitational force with the knee at 90 degrees. © 1972 The American College of Sports Medicine.
Medicine and Science in Sports
Jackson, Richard T. and Merrifield, H. H., "Electromyographic assessment of quadriceps muscle group during knee extension with weighted boot" (1972). Faculty Articles Indexed in Scopus. 2770.