PT793- Lumbar Spine

External Oblique

O: external surfaces 5th-12th ribs

I: linea alba, pubic tubercle, anterior iliac crest

A: compress and support abdominal viscera, flex and rotate trunk

In: thoraco-abdominal nerve and subcostal nerve

Internal oblique

O: Thoracolumbar fascia, anterior iliac crest, CT deep to inguinal ligament

I: inferior borders of ribs 10-12, linea alba, pecten pubis via conjoint tendon

A:compress and support abdominal viscera, flex and rotate trunk

In: thoraco-abdominal nerve and first lumbar nerve

rectus abdominus

O:pubic symphysis and crest

I: xiphoid process, 5th and 7th costal cartilages

A: flex trunk, compress abdominal viscera, stabilize and control tilt of pelvis

In: thoraco-abdominal nerve

transversus abdominus

O:internal surface costal cartilages 7-12, thoracolumbar fascia, iliac crest, CT deep to inguinal ligament

I:linea alba, pubic crest, pecten pubis via conjoint tendon

A: compress and support abdominal viscera

In: thoraco-abdominal nerve and 1st lumbar nerve

Erector Spinae Muscles

O: broad tendon from posterior iliac crest, posterior sacrum, sacro-iliac ligaments, supraspinous ligament, sacral and inferior lumbar spinous processes

I: Iliocostalis: angles of lower ribs and cervical transverse processes

longissimus: b/w tubercles and angles of ribs, cervical and thoracic transverse processes, mastoid process

spinalis: upper thoracic spinous processes, cranium

A: acting bilaterally- extend vertebral column and head, eccentric control when back is flexed

Acting unilaterally- laterally flex vertebral column

In: posterior rami of spinal nerves

Multifidi

O:sacrum, iliac spine, transverse processes

I: spinous processes 2-4 segments superior

A: extension, stabilizes vertebrae during local movements of the vertebral column

In: posterior rami of spinal nerves

Rotatores

O: transverse processes of vertebrae

I: junction of transverse processes and lamina of vertebrae 1-2 segments superior

A: extension, stabilize vertebrae, assist with local extension and rotatory movements of the VC

In: posterior rami of spinal nerves

Semispinalis

O: transverse processes of vertebrae

I: occipital bone and spinous process of thoracic and cervical vertebrae 4-6 segments superior

A: extension and contralateral rotation of the head and thoracic/cervical regions of the VC

In: posterior rami of spinal nerves

action of interspinale

aid extension and rotation of the vertebral column

action of intertransversarii

aids in lateral flexion of the vertebral column, acts bilaterally to stabilize

levetores costarum

O: tips of transverse processes of vertebrae

I: between angles and tubercles of ribs

A: elevate ribs to assist respiration, assist with lateral flexion of the VC

In: posterior rami of spinal nerves C8-T11

Quadratus Lumborum

O: medial inferior border of ribs and lumbar transverse processes

I: iliolumbar ligament and internal lip of iliac crest

A: extends and laterally flexes VC, fixes 12th rib during inspiration

In: anterior branches T12 and L1-4 nerves

Psoas Major

O: lumbar transverse processes, sides of vertebral bodies and intervening IV discs

I: lesser trochanter of femur by strong tendon

A: flex thigh, laterally flex VC, laterally balance trunk, flex trunk in sitting

In: anterior rami of lumbar nerves L1, L2, L3