muscles; origins, insertions, and actions

temporalis origin

temporal fossa

temporalis insertion

coronoid process

temporalis action

elevates/retracts the mandible

sternocleidomastoid origin

superior anterior manubrium; medial clavicle

sternocleidomastoid insertion

mastoid process, lateral part of the superior nuchal line

sternocleidomastoid action

bend neck forward, rotation of head

rectus abdominus origin

pubis

rectus abdominus insertion

xiphoid process, costal cartilage 5-7

rectus abdominus action

flexion of trunk, breathing

iliopsoas origin

transverse process of L1-L5, iliac crest

iliopsoas insertion

greater trochanter of femur

iliopsoas action

flexion of thigh

pectoralis major origin

anterior, medial clavicle; sternum and costal cartilage 1-6

pectoralis major insertion

intertubercular groove

pectoralis major action

arm adduction, internal rotation

latissimus dorsi origin

spinous process of T7-12, posterior iliac crest, ribs 9-12, inferior angle of scapula

latissimus dorsi insertion

intertubercular groove

latissimus dorsi action

arm adduction

deltoid origin

lateral clavicle, acromion process, spine of the scapula

deltoid insertion

deltoid tuberosity of humerus

deltoid action

arm abduction

biceps brachii origin

coracoid process of the scapula, superglenoid tubercle

biceps brachii insertion

radial tuberosity

biceps brachii action

flexion and supination of the forearm

triceps brachii origin

infraglenoid tubercle, posterior humerus

triceps brachii insertion

olecranon process of the ulna

triceps brachii action

extension and adduction of the forearm

extensor digitorum origin

lateral epicondyle of the humerus

extensor digitorum insertion

digits 2-5

extensor digitorum action

finger extension 2-5

flexor digitorum superficialis origin

medial epicondyle of the humerus, coronoid process of the ulna, proximal anterior radius

flexor digitorum superficialis insertion

middle phalanges 2-5

flexor digitorum superficialis action

flexion of the fingers

gluteus maximus origin

lateral posterior surface of the sacrum and coccyx, posterior ilium

gluteus maximus insertion

gluteal tuberosity of the femur

gluteus maximus action

thigh extension, external rotation

rectus femoris origin

anterior inferior iliac spine

rectus femoris insertion

tibial tuberosity

rectus femoris action

thigh flexion, leg extension

biceps femoris origin

ischial tuberosity

biceps femoris insertion

lateral head of fibula

biceps femoris action

thigh extension, thigh external rotation, leg flexion and external rotation

gastrocnemius origin

lateral condyle of the femur

gastrocnemius insertion

posterior calcanus (achilles tendon)

gastrocnemius action

plantar flexion

tibialis anterior origin

lateral surface of the tibia

tibialis anterior insertion

medial cuneiform, base of metatarsal 1

tibial anterior action

foot dorsiflexion, inversion

supraspinatus origin

supraspinous fossa of the scapula

supraspinatus insertion

greater tubercle of the humerus

supraspinatus action

arm abduction

infraspinatus origin

infraspinous process of the scapula

infraspinatus insertion

greater tubercle of the humerus

infraspinatus action

arm external rotation

teres minor origin

lateral border of scapula

teres minor insertion

greater tubercle of humerus

teres minor action

arm external rotation, adduction

subscapularis origin

subscapular fossa of the scapula

subscapularis insertion

lesser tubercle of the humerus

subscapularis action

arm internal rotation