Anatomy Muscle Locations and Actions

Achilles Tendon

Posterior ankle, plantarflexion of foot

biceps brachii

anterior upper arm, flexes forearm

biceps femoris

posterior thigh, flexes knee, extends thigh/hip

semitendinosus

posterior thigh, flexes knee, extends thigh/hip

semimembranosus

posterior thigh, flexes knee, extends thigh/hip

deltoid

shoulder, abducts arms

erector spinae

parallel to spine (both sides), extends trunk

Extensors

posterior hand, wrist, forearm extends fingers, wrist, forearm

External oblique

ventral/lateral abdominal tenses abdominal wall

flexors

anterior hand, wrist, forearm, flexes wrist, and fingers

Gastrocnemius

calf/posterior lower leg, plantarflexion and knee flexion.

Gluteus maximus

buttocks, extends hip

Gluteus medius

buttocks, deep to maximus abducts thigh, internally rotates hip

Gracilis

groin, inner thigh, adducts thigh

hamstrings

posterior thigh, flexes leg/knee, extends thigh/hip

Internal oblique

ventral/lateral abdominals, tenses abdominal wall

latissimus dorsi

lateral trunk, extends and adducts arms, medially rotates humerus

Masseter

jaw/chin, closes jaw

pectoralis major

chest, adducts arms and pulls arms across chest

pectoralis minor

chest, deep to major adducts arms and pulls arms across chest

Pronator

forearm, rotates forearm medially

quadriceps femoris

anterior thigh, extends knee, flexes hip

Rectus abdominis

ventral trunk, tenses abdominal wall, flexes vertebral column

Rectus femoris

anterior thigh, extends knee, flexes hip

vastus medialis

anterior thigh, extends knee, flexes hip

vastus lateralis

anterior thigh, extends knee, flexes hip

vastus intermedius

anterior thigh, extends knee, flexes hip

rhomboids

between scapula and spine, raises and adducts scapula

serratus anterior

dorsal/lateral trunk, pulls scapula anterior/inferior

soleus

posterior lower leg, plantarflexion of foot

Sternocleidomastoid

anterior neck, rotates head, pulls head lateral/inferior

teres major

posterior shoulder, extends and adducts arms, medially rotates humerus

Teres minor

posterior shoulder, laterally rotates humerus

Tibialis anterior

anterior lower leg, dorsiflexion and inversion

transversus abdominis

ventral/lateral abdom, tenses abdominal wall

Trapezius

posterior neck/shoulder, raises and rotates arms/scapula

triceps brachii

posterior upper arm, extends forearm