Hip Extension the agonist would be Glutues Maximus
gluteus maximus
Illiacus, psoas major, the rectus femoris
An agonist muscle is a muscle that plays a part in the extension of a muscle. The agonist muscles for a knee extension are the quadriceps and hamstrings.
Agonist(s) - Gluteus Maximus/Quadriceps FemorisSynergist(s) - Biceps Femoris (Hamstrings)Stabilizer(s) - Transversus AbdominisAntagonist(s) - Hip Flexors (Mainly the Iliopsoas)Movement(s) - Hip Extension/Knee ExtensionPlanes - Sagittal PlaneYour agonist(s) (when done properly i.e. sitting back/knees out) for a squat will be your glutes and quadriceps. Your synergist(s) will actually be your hamstrings as the biceps femorislong head assists greatly in hip extension. Your antagonist(opposing muscle) during a squat will be your Hip flexors i.e. Hip flexion.
prime mover (agonist)
Primer Mover (agonist)
The hamstring and gluteal (buttocks) muscles.
Rectus femoris+ anterior thigh; quadriceps+ extension of leg at knee Vastus lateralis+ lateral anterior thigh; quadriceps+ extension of leg at knee Vastus Medialis+ medial anterior thigh; quadriceps+ extension of leg at knee Vastus intermedius+ deep anterior thigh; quadriceps+ extension of leg at knee Sartorius (*) parallel strap-like muscle that crosses thigh flexion of knee forward Biceps femoris* posterior thigh; hamstring* flexion of leg at knee Semitendinosus* posterior thigh; hamstring* flexion of leg at knee Semimembranosus* posterior thigh; hamstring* flexion of leg at knee
yesabduct the thigh
Antagonist: lats Agonist: Abdominals
Flexor carpi
in the arm: bicep contracts (agonist) triceps relax (antagonist) in the leg: hamstrings contract (agonist) quadriceps relaxes (antagonist) remember the agonist is the muscle "agonising" to do the work - like pulling the joint.
The muscles used in the leg press exercise are your Quads primarily. Hamstring gets a good work out too.
Agonist - Pectoralis Major, Triceps Brachii Antagonist - Bicep Brachii, Latissimus Dorsi