Spine & Pelvis Muscles

Front 1

Cremaster

Back 1

attachment- from the medial edge of the internal oblique to spermatic cord actions- elevation of testis innervation- genitofemoral nerve

Front 2

Diaphragm

Back 2

attachments- from xiphoid process, inner surface of the lower ribs & costal cartilages, medial & lateral arcuate ligaments & lumbar vertebrae via the crura to the central tendon actions- inspiration (negative thoracic pressure by inferior displacement) innervation- phrenic nerve C3-5

Front 3

External Oblique

Back 3

attachments- from lower 8 ribs to iliac crest & rectus sheath actions- flexion & rotation of the trunk, & compression of the abdominal cavity innervation- ventral rami (T5-6), T7-12

Front 4

Internal Oblique

Back 4

attachments- from thoracolumbar fascia to inguinal ligament, iliac crest & rectus sheath actions- flexion & rotation of the trunk, & compression of the abdominal cavity innervation- lower thoracic & L1 ventral rami T7-12, L1, iliohypogastric and ilioinguinal, ventral rami

Front 5

Quadratus Lomborum

Back 5

attachments- from 12th rib & transverse processes of L1-4 to iliolumbar ligament & iliac crest actions- extension & lateral flexion of the trunk, and fixes 12th rib during respiration innervation- Lumbar plexus ventral rami T12-L3

Front 6

Rectus Abdominus

Back 6

attachments- from xiphoid process & adjacent costal cartilages of ribs 5-7 to pubic crest & tubercle (symphysis) actions- flexion of trunk & compression of abdominal cavity innervation- lower thoracic ventral rami T5-12

Front 7

Transversus abdominis

Back 7

attachments- from lower six costal cartilages & thoracolumbar fascia to inguinal ligament, iliac crest & rectus sheath actions- compression of the abdominal cavity innervation- lower thoracic & L1 ventral rami T7-12, L1 iliohypogastric and ilioinguinal, ventral divisions

Front 8

Coccygeus

Back 8

attachments- from ischial spine & sacrospinous ligament to coccyx actions- supports & compresses

Front 9

Levator ani

Back 9

attachments- from pubic symphysis, obturator fascia & ischial spine to midline raphe & anococcygeal ligament actions- supports pelvic viscera, & compresses rectum & vagina innervation- pudendal nerve & S4

Front 10

Bulbospongiosus

Back 10

actions- in male empties urethra, maintains erection & contracts during ejaculation; in female constricts vaginal orifice & contributes to erection of clitoris innervation- perineal branch of pudendal nerve

Front 11

Ischiocavernosus

Back 11

actions- compresses crus during erection innervation- perineal branch of pudendal nerve

Front 12

Sphinctor ani externus

Back 12

actions- closes anal canal & fixes perineal body innervation- inferior rectal branch of pudendal nerve

Front 13

Sphincter urethrae

Back 13

attachments- surrounds urethra actions- compresses urethra innervation- perineal branch of pudendal nerve

Front 14

Erector spinae

Back 14

attachments- from TLF attached to the sacrum, iliac crest, spinous processes L5-T11, supraspinous lig., angles of ribs to costal angles (iliocostalis), ribs & transverse processes (longissimus), and spinous processes (spinalis) actions- extension & lateral flexion of the vertebral column innervation- dorsal rami of spinal nerves

Front 15

Semispinalis

Back 15

attachments- from transverse processes to distant superior spinous processes actions- extension & contralateral rotation of the vertebral column innervation- dorsal rami of spinal nerves

Front 16

Multifidus and rotatores

Back 16

attachments- from sacrum, posterior SI ligament, posterior iliac spine, transverse processes to more superior

Front 17

Rectus capitus posterior major

Back 17

attachments- from spinous process C2 to lateral aspect inferior nuchal line actions- extension and ipsilateral rotation innervation- suboccipital nerve

Front 18

Rectus capitus posterior minor

Back 18

attachments- from tubercle on posterior arch C1 to medial aspect inferior nuchal line action: extension innervation: suboccipital nerve

Front 19

Obliquus capitus inferior

Back 19

attachments: from spinous process of C2 to transverse process C1 action: ipsilateral rotation innervation: suboccipital nerve

Front 20

Obliquus capitus superior

Back 20

attachments: from transverse process of C1 to area between superior and inferior nuchal lines on occipital bones actions: extension and lateral flexion innervation: suboccipital nerve

Front 21

Splenius cervicis

Back 21

attachments: from spinous processes of T3-T6 to posterior tubercles of transverse processes of first 3 cervical vertebrae actions: extension, lateral flexion, ipsilateral rotation innervation: dorsal rami of spinal nerves

Front 22

Splenius capitis

Back 22

attachments: from ligamentum nuchae and spinous processes T4-C7 actions: extension, lateral flexion, ipsilateral rotation innervation: dorsal rami of spinal nerves

Front 23

Longus colli

Back 23

attachments: from anterior tubercles and bodies T3-C3 to anterior tubercles and bodies C6-C1 actions: flexion, lateral flexion, ipsilateral rotation innervation: ventral rami of spinal nerves (C2-7)

Front 24

Longus capitis

Back 24

attachments: from anterior tubercles C3-C6 to basilar portion occipital bone actions: flexion, ipsilateral rotation innervation: ventral rami of spinal nerves (C1-3)

Front 25

Rectus capitis anterior

Back 25

attachments: from transverse process and anterior surface C1 to basilar portion occipital bone actions: flexion innervation: ventral rami of spinal nerves (C1-2)

Front 26

Rectus capitis lateralis

Back 26

attachments: from transverse process C1 to jugular process occipital bone action: lateral flexion innervation: ventral rami of spinal nerves (C1-2)