Muscles of Abdomen and Thorax; origin, insertion

transversus thoracis

O: Posterior surface of the body of the sternum, posterior surface of the xiphoid process, and the sternal ends of costal cartilages of the lower 3 or 4 true ribs Insertion: by slips into the lower borders and inner surfaces of the costal cartilages of ribs 2-6

Quadratus Lumborum

O: aponeurotic fibers from the iliolumbar ligament and the adjacent portion of iliac crest I: lower border of the last rib for about half its length and transverse processes of L01-L04

Scalenes

Origin: Anterior tubercles of the transverse processes of the 3rd, 4th, 5th, and 6th cervical vertebrae Insertion: Scalene tubercle on the inner border and upper surface of the 1st rib.

Rectus Abdominis

Origin: Crest of the pubis and pubic tubercle; front of the pubic symphysis Insertion: pubis, cartilages of 5th, 6th, and 7th ribs, xiphoid process

Transversus Abdominis

Origin: Lateral third of the inguinal ligament, inner lip of the iliac crest, inner surface of cartilages of the lower six ribs, lumbodorsal fascia, and interdigitating with the diaphragm Insertion: Ends in an aponeurosis. The upper three-fourths form the back of the rectus sheath and insert on the linea alba; the lower fourth forms the front of the rectus sheath and attaches to the pubis.

Internal Intercostals

Origin: Superior border of ribs 2-12 Insertion: Inferior border of ribs above 1-11

Semispinalis capitis

Origin: Tips of the transverse processes of the upper six or seven thoracic and the seventh cervical vertebrae and from the articular processes of the three cervical above this. Insertion: between the superior and inferior nuchal lines of the occipital bone

Serratus Anterior

Origin: Upper 8-9 ribs Insertion: Medial border of scapula

Diaphragm

Origin: Xiphoid process, cartilages of ribs 7-12, anterior surfaces of the lumbar vertebrae, crura of the upper two (left crus) and three (right crus) lumbar vertebrae Insertion: Central Tendon that blends with the anterior longitudinal ligament of the vertebral column

Internal Oblique

Origin: lateral half of the inguinal ligament, the middle lip of the iliac crest, and the lumbodorsal (thoracolumbar) fascia Insertion: pubis, inferior border of the lower 3-4 ribs, linea alba; the aponeurosis fuses with the external oblique to form the rectus sheath

External Oblique

Origin: sternum, external surfaces and inferior borders of the lower eight ribs (5-12) Insertion: Pubis, linea alba via an aponeurosis and the iliac crest

Multifidus

origin: Sacrum, posterior superior iliac spine, mammillary processes of lumbar vertebrae, transverse processes of the thoracic vertebrae, articular processes of cervical vertebrae C04-C07 insertion: spinous process 2-4 vertebrae superior to the origin

Semispinalis Cervicis

origin: Transverse processes T01-T06 insertion: spinous processes C02-C07

Semispinalis Thoracis

origin: Transverse processes of T06-T12 insertion: spinous process of C06-T04

Iliocostalis

origin: iliac crest and lateral portion of the common erector spinae tendon insertion: inferior borders of the angles of the lower six or seven ribs

External Intercostals

origin: lower border of ribs 1-11 insertion: upper border of ribs below 2-12

splenius capitis

origin: lower half of ligamentum nuchae ad spinous processes of seventh cervical vertebra through the upper three or four thoracic vertebrae (C07-T03) insertion: mastoid process temporal bone and occipital bone

Longissimus

origin: posterior surfaces of the transverse processes and accessory processes of the lumbar vertebrae insertion: the tips of the transverse processes of all the thoracic vertebrae,

Pectoralis Minor

origin: ribs 3-5 insertion: coracoid process of the scapula

Spinalis

origin: spinous process of 1st 2 lumbar and last 2 thoracic vertebrae insertion: spinous process of upper thoracic vertebrae (4-8), spinous process of vertebrae C02-C05

Splenius Cervicis

origin: spinous processes of T03-T06 insertion: transverse processes of C01-C03

Serratus Posterior Superior

origin: supraspinal ligament, the ligamentum nuchae and the spinous processes of the upper two (or three) thoracic vertebrae (T01-T03); the seventth cervical vertebra (C07) insertion: Upper borders of ribs 2-5

Serratus Posterior Inferior

origin: the supraspinal ligament; and the spinous processes of the upper two (or three) lumbar vertebrae (L01-L03), and the lower two thoracic vertebrae (T11, T12) insertion: lower borders of ribs 9-12

Intertransversarii

origin: transverse process of the vertebra insertion: adjacent vertebra; posterior tubercles of transverse processes; anterior tubercles of transverse processes

Rotatores

origin: transverse processes of each thoracic vertebrae insertion: spinous process of the vertebra above each respective origin