The antagonist muscle group during the seated leg extension exercise is which of the following?

During the seated leg extension exercise, the primary muscle group being worked is the quadriceps, which are responsible for extending the knee. The antagonist muscle group, which opposes the action of the quadriceps, is the hamstrings. As the quadriceps contract to extend the leg, the hamstrings must relax and lengthen to allow this motion to occur effectively. This relationship between agonist (the muscle performing the action) and antagonist (the muscle opposing that action) is fundamental to understanding how muscles work together during movements. The other muscle groups listed, such as the glutes and calves, do not directly oppose the action of knee extension in this specific exercise, making them not the proper antagonist for the seated leg extension.