Muscles of the lower back and abdominal wall Flashcards
What are the main 3 spinal diseases that result in abnormal curvatures of the spine?
And what direction do they each curve in?
- Scoliosis; abnormal lateral curvature of the spine.
- Kyphosis; excessive posterior thoracic curvature.
- Lordosis; excessive anterior lumbar curvature.
There are 3 different layers that different Back muscles reside in, each layer is associated with different movements of the back.
What layers are there and what movements are they associated with?
- Deep layer; Associated with movements of the vertebral column.
- Intermediate layer; Associated with movements of the thoracic cage.
- Superficial layer; Associated with movements of the shoulder.
The deep layer of back muscles are further dived again into what 3 sub-layers?
- Superficial.
- Intermediate
- Deep.
What deep back muscles reside in the deep-superficial layer?
And what movements are they responsible for?
The pair of muscles are known as: Spinotraversales.
- Splenius capitis.
- Splenius cervicis.
They’re both responsible for movements of the head and neck.
What deep back muscles reside in the deep-intermediate layer?
And what movements are they responsible for?
These are bilateral muscles that lye either side of the spine. They’re ordered from most medial –> Lateral.
As a group they’re known as the erector spinae muscles, aka intrinsic back muscles.
- Spinalis
- Longissimus
- Iliocostalis
These muscles work unilaterally, to laterally flex the vertebral column, and bilaterally they extend the vertebral column and the head.
What innervates the Erector spinae muscles, aka intrinsic back muscles.
Innervated by posterior rami of spinal nerves.
What deep back muscles reside in the deep-deep layer?
And what movements are they responsible for?
They’re known as the Transversospinales muscles.
- Semispinalis; Bi-lateral, more lateral
- Multifidus; Bi-lateral, more medial,
- Rotatores; smaller muscles
Movements:
Semispinalis; Extends and rotates the head contralaterally.
Multifidus and rotatores: stabilise the vertebral column.
What innervates the Transversospinales muscles?
Innervated by posterior rami of spinal nerves.
What are the minor deep intrinsic muscles?
- Intertransversarii
- Interspinales
- Levatores costarum, attaches to C7 - T11 vertebrae, and the ribs.
What back muscles make up the Superficial layer?
- Trapezius.
- Levator scapulae.
- Latissimus dorsi.
- Rhomboid minor.
- Rhomboid major.
What back muscles make up the intermediate layer?
- Serratus posterior superior.
- Serratus posterior inferior.
What is the name of the facia that is throughout most of the posterior thoracic and abdomen?
Thoracolumbar facia
How many layers does the Thoracolumbar facia have?
3
What is the role of the Thoracolumbar facia?
- Stabilising and mobility of the region.
- Stabilise the pelvis
What muscles are present between the middle and posterior layer of the Thoracolumbar facia?
The deep muscles of the back.
What muscle is between the middle and anterior layer of the Thoracolumbar facia?
Quadratus lumborum
What are the movements of the vertebral column?
- Flexion.
- Extension.
- Lateral flexion.
- Rotation.
What limits the ROM of the vertebral column?
- The thickness, elasticity and compressibility of the intervertebral discs.
- The shape, orientation and articular capsules of the facet joints.
- The resistance of the back muscles and ligaments. e.g. Ligamenta flava.
Starting superiorly, what are the layers of the abdomen?
- Skin.
- Subcutaneous tissue/ superficial facia. Made of two layers the fatty layer and membranous layer.
- Muscular layer.
- Fascia transversalis.
- Parietal peritoneum.
What are the 3 paired (Bi-lateral) flat muscles of the anterior and lateral abdominal wall?
- External oblique: most superficial
- Internal oblique
- Transverse abdominis: Deepest
What is the 1 paired(Bi-lateral) strap muscle of the anterior abdominal wall?
Rectus abdominis.
What innervates the muscles of the anterior and lateral abdominal wall?
- Thoracoabdominal nerves (T7-T11).
- Subcostal nerve (T12).
- The lower parts of internal oblique and transverse abdominis muscles are also innervated by the branches of the lumbar plexus.
What is the function of the External oblique muscle?
- Contralateral rotation of the torso.
What is the function of the internal oblique?
- Bi-lateral contraction, compresses the abdomen.
- Unilateral contraction rotates the torso ipsilaterally.
What is the function of the Transverse abdominis?
- Compression of abdominal contents.
What is the function of the Rectus abdominis?
- Assist the flat muscles in compression of the abdominal viscera.
- Stabilises the pelvis during locomotion.
What is the small muscle below rectus abdominis?
- Pirimedalis (idk the spelling)
What is the function of Pirimedalis
- It facilitates in tensing the linea alba.
Reminder
LEARN THE DERMATOMES!!
What is Sciatica?
Compression/ irritation of the sciatic nerve.
What can cause Sciatica?
- Injury, disc herniation, spinal stenosis and spondylolisthesis.
What are the primary curvatures of the spine?
These curve anteriorly:
- Thoracic
- Sacrococcygeal
What are the secondary curvatures of the spine?
These curve posteriorly:
- Cervical
- Lumbar
