Muscle origin, insertion, action

Masseter

Origin- zygomatic arch

Insertion- angle of mandibles ramus

Action- elevates mandible

Sternocleidomastoid

Origin of clavicular head- sternal end of clavicle

Origin of sternal head- manubrium

Insertion- mastoid process

Action- flexion of neck

Pectoralis major

Origin- cartilage of ribs 2-6

Insertion- greater tubercle and bicipital groove

Action- flexion of shoulder

Serratus anterior

Origin- anterior ribs 1-9

Insertion- anterior surface of vertebral border of scapula

Action- protracts shoulder

Rectus abdominis

Origin- superior surface of pubis

Insertion- inferior surface of cartilage on ribs 5-7

Action- depresses ribs

Trapezius (upper, middle, lower)

Origin of upper fibers- occipital bone

Origin of middle fibers- spinous processes of T1-T3

Origin of lower fibers- spinous processes of T4-T12

Insertion- spine of scapula

Action of upper fibers- elevates scapula

Action of middle fibers- retracts scapula

Action of lower fibers- depresses scapula

Deltoid (anterior, middle, posterior)

Origin of anterior fibers- lateral part of clavicle

Origin of middle fibers- acromion process

Origin of posterior fibers- spine of scapula

Insertion- deltoid tuberosity

Action of ALL fibers- abduction of arm

Biceps brachii (long and short heads)

Origin of long head- supraglenoid tubercle

Origin of short head- coracoid process

Insertion- radial tuberosity

Action- flexion of elbow and shoulder

Triceps brachii (lateral, long, and medial)

Origin of lateral head- superior lateral margin of humerus

Origin of long head- infraglenoid tubercle

Origin of medial head- posterior surface of the humerus

Insertion- olecranon process

Action- extension of forearm

Tensor fascia latae

Origin- lateral surface of anterior superior iliac spine

Insertion- iliotibial tuberosity

Action- abduction of thigh

Rectus femoris

Origin- anterior inferior iliac spine

Insertion- tibial tuberosity

Action- extension of knee

Gluteus Maximus

Origin- iliac crest

Insertion- gluteal tuberosity of femur

Action- extension of knee

Tibialis anterior

Origin- lateral condyle and proximal shaft of tibia

Insertion- base of first metatarsal and lateral cuneiform

Action- dorsiflexion at ankle

Gastrocnemius (lateral and medial head)

Origin of lateral head- lateral condyle of femur

Origin of medial head- medial condyle of femur

Insertion- calcaneus via calcaneal tendon

Action- planar flexion

Soleus

Origin- head and proximal shaft of fibula

Insertion-calcaneus vis calcaneal tendon

Action- plantar flexion