Jan 18, 2013 - 11:48 AM
The agonist is the muscle that contracts to perform a movement and the antagonist has to relax and stretch in order for the movement to occur. For example let’s use a bicep curl, here your bicep is the agonist (the muscle contracting to perform a movement) and the antagonist would be your triceps (which has to relax and go into stretch in order for a movement to be produced.) If the antagonist doesn’t relax and allow for a stretch no movement will occur.
Jan 18, 2013 - 12:17 PM
Jan 18, 2013 - 12:59 PM
Synergist muscles work with the prime mover in order to produce the movement. They are smaller muscles that are around that main muscle, in a squat - (what is the agonist for one is the antagonist for the other as these movement mirror each other)
biceps femoris - Prime mover
semitendinosus - synergist
semimembraneosus - synergist.
Knee Extension -
rectus femoris - Prime mover
vastus medialis - synergist
vastus lateralis - synergist
vastus intermedius - synergist
Stabilizer muscles contract to keep you body in position, in a squat they would be muscles in your abdomen and lower back, etc.
below is from the live strong page. i dont have the book so this may help some
The clavicular, or upper, head of the pectoralis major is used during the military press. This muscle acts as a synergist of the anterior fibers of the deltoids to flex the upper arm and press the bar upward. The anterior deltoid and clavicular head of the pectoralis major can be targeted by using a narrow grip with your elbows facing forward.Triceps Brachii
The triceps brachii is a large, three-headed muscle located on the back of the upper arm. It is the prime arm extensor and works powerfully to extend your arm in the upward phase of the military press exercise.Trapezius
The trapezius is the most superficial muscle of the back. This muscle is responsible for the up and down movements of the shoulder blades throughout the exercise.Serratus Anterior
The serratus anterior lies beneath the pectoral muscles and works to rotate the shoulder blades laterally and upward as you press the barbell up and down during the military press exercise.