BIO 1016 Muscles (origin, insertion, action)

Frontalis

O- epicranial aponeurosis

I- skin of eyebrows

A- raise eyebrows

Occipitalis

O- occipital bone

I- epicranial aponeurosis

A- pull scalp backward (posteriorly)

Sternocleidomastoid

O- manubrium + clavicle

I- mastoid process of skull

A- flex the neck + rotate head

Pectoralis major

O- clavicle, sternum, costal cartilages 1-7

I- greater tubercle of humerus

A- adduct, flex, and medially rotate arm

Coracobrachialis

O- coracoid process of scapula

I- medial shaft of humerus

A- flex + abduct arm at the shoulder

Triceps brachii

O- scapula, medial + lateral head of humerus

I- olecranon of ulna

A- extend forearm

Supinator

O- lateral epicondyle of humerus + proximal ulna

I- lateral surface of radius

A- supinate the forearm

Pronator teres

O- medial epicondyle of humerus + coronoid process of ulna

I- lateral surface of radius

A- pronate the forearm

Gluteus maximus

O- ilium, sacrum, coccyx

I- gluteal tuberosity of femur, iliotibial tract

A- extend hip + laterally rotate thigh

Gluteus medius

O- ilium between anterior and posterior line

I- greater trochanter of femur

A- abduct (away from midline) and medially rotate thigh

Bicep femoris (lateral hamstring)

O- ischial tuberosity

I- head of fibula

A- flex knee

Semitendinosus (top of membranosus, sort of medial)

O- ischial tuberosity

I- proximal tibia

A- flex knee

Semimembranosus (deep to tendinosus, medial)

O- ischial tuberosity

I- medial tibia

A- flex knee

Rectus femoris

O- ilium

I- patella + tibial tuberosity

A- flex the hip + extend the knee

Vastus lateralis

O- greater trochanter of femur

I- patella + tibial tuberosity

A- extend the knee

Vastus medialis

O- intertrochanteric

I- patella + tibial tuberosity

A- extend the knee

Vastus intermedius (under rectus femoris)

O- anterior femur shaft

I- patella + tibial tuberosity

A- extend the knee

Gastrocnemius

O- medial and lateral condyles of femur

I- calcaneus through Achilles tendon

A- plantar flexion

Soleus (deep behind gastrocnemius)

O- proximal tibia + fibula

I- calcaneus (through Achilles tendon)

A- plantar flexion