Musculo Skeletal Anatomy - Week 4 - Osteology and muscles of the Lumbar Region Flashcards
What are the functions and movements of the lumbar vertebrae:
Functions:
* Weight bearing of the upper body
Movements:
Flexion and extension, some lateral
flexion, limited/restricted rotation
List the bony landmarks of the lumbar vertebrae.
Vertebral body:
Large and wide, kidney shaped.
Vertebral foramen:
Triangular, larger then thoracic vertebrae, smaller then cervical region.
Laminae:
Strong, broad and short in morphology.
Transverse process:
Long and slender.
Mammilary process:
located on the posterior aspect of the superior articular facet.
Spinous process:
Short and blunt, hatchet shaped.
Superior and inferior articular process:
- Superior facet face medially
- Inferior facet face laterally.
List the joints of the lumbar vertebrae.
Intervertebral joint
Facet joints
- J or C curved
Functions:
* Protect from anterior shear, rotation,
and flexion
- Produces spinal motions including
coupling movements - Minimally restricts extension and side
bending
List the muscles in the Lumbar region.
- Quadratus lumborum
- Erector Spinae group
- Abdominal muscles
- Accessory muscles
(Transversospinalis group and intertransversarii)
Where is the Quadratus Lumborum located and what are its functions?
Location:
Run diagonally from the rib and spine inferiorly and
laterally towards iliac crest.
Functions:
* Laterally flexes the trunk
* Extend the trunk when both contract
* Stabilizes the 12th rib during breathing
Where is the Erector spinae group located and what are its functions?
Location:
Extend on either side of the vertebral column, between the base of the cranium superiorly and pelvis.
Function:
* Important role in lumbar stabilization
by providing compressive forces along
the spine
* Assist with trunk extension, spine
stability and leg speed enhancement
* Stabilize the spinal curvatures
List the three muscles that make up the erector spinae group.
Iliocostal muscle:
- Iliocostalis colli (cervical region)
- Iliocostalis thoracis
(thoracic region)
- Iliocostalis lumborum (lumbar region)
Longissimus muscle:
- It is divided into three parts (capitis, cervicis,
thoracis).
Spinalis muscle:
- Thoracic part attaches to the Spinous processes
of the upper lumbar vertebra (L1, L2).
List the main muscle in the transversospinalis group for the lumbar region. Where is it located? What is its function?
List the other two muscles apart of this group.
Multifidus
Location:
Multifidus lumborum attaches to
the mammillary processes
extending superiorly to the
Spinous process of vertebrae two- five levels above.
Functions:
Very important muscles for
stabilizing and contralateral
rotation of the spine.
Other muscles apart of this group:
Rotares
Semispinalis
List the two Intertransversarii muscles and where they are located.
Lateral intertransversarii lumborum
Location:
Attachments between the
transverse and accessory processes of L1-L4 and the transverse process of the succeeding vertebra.
Medial intertransversarii lumborum:
Location:
Extend between the accessory processes
of each vertebra L1-L4 to the anterior
tubercle of the transverse process of the
vertebra below.
What are the movements/biomechanics of the lumbar spine?
Flexion
* Superior vertebra will anterior tilt
and forward gliding will occur
* Facet joints open up
Extension
* Superior vertebra will tilt and glide
posteriorly
* Facet joints close
Flexion
is resisted by:
* Joint capsule ~39%
* Supraspinous / interspinous
ligaments ~ 19%
* Ligamentum flavum ~ 13%
* IVD ~29%
Extension
is resisted by
* Structures anterior to the fulcrum to
be elongated (i.e. ALL, etc.)
* Ability of IVD to compression
* Joint capsule tension
* Passive tension of Psoas major
