Muscle Action Groups

Major muscle groups, and the agonists and antagonists for flexion and extension ❤️

Agonist/prime mover

main muscle for a movement

synergist

muscles that help the agonist by giving extra force or stabilizing a movement

fixator

muscles that stabilize bone while other things are moving

antagonist

muscle theat reverses/opposes the actions of the prime mover (relaxes when agonist is active or slightly retract to limit movement)

Flexor/flexion muscles are located on

anterior/front (except for femoral muscles)

Extension muscles are located on the

dorsal/back side (except femoral muscles)

Elbow flexion agonist

Brachialis

Elbow flexion antagonist

Triceps Brachii

Elbow extension agonist

Triceps Brachii

Elbow extension antagonist

brachialis

Knee extension agonist

quadriceps femoris group

knee extension antagonist

hamstring group

knee flexion agonist

hamstring group

knee flexion antagonist

quadriceps femoris group

hip flexion agonist

Iliopsoas (psoas major and iliacus)

hip flexion antagonist

gluteus maximus

hip extension agonist

gluteus maximus

hip extension antagonist

iliopsoas

shoulder flexion agonist

anterior deltoid

shoulder flexion antagonist

posterior deltoid

shoulder extension agonist

posterior deltoid

shoulder extension antagonist

anterior deltoid

shoulder abduction agonist

deltoid (middle fibers)

shoulder abduction antagonist

latissimus dorsi

shoulder adduction agonist

latissimus dorsi

shoulder adduction antagonist

deltoid (middle fibers)

ankle plantar flexion agonist

gastrocnemius, soleus

ankle plantar flexion antagonist

tibialis anterior

ankle dorsiflexion agonist

tibialis anterior

ankle dorsiflexion antagonist

gastrocnemius, soleus

Trunk flexion agonist

rectus abdominus

trunk flexion antagonist

erector spinae

trunk extension agonist

erector spinae

trunk extension antagonist

rectus abdominus