VERTEBRAL COLUMN 3 Flashcards
Thoracic region
Wedge shaped vertebrae = primary cause of thoracic kyphosis - ANTERIOR HEIGHT OF VB IS LESS THAN POSTERIOR WHICH GIVES A WEDGED SHAPED
Low disc: vertebral body height
Tall, coronal superior articular processes limit flexion - TALL AND VERTICAL IN CORONAL PLANE
Coupling of movements in the thoracic spine:
Upper thoracic: lateral flexion & ipsilateral rotation coupling
When the inferior articular process of the superior vertebrae slides inferiorly it also moves
posteriorly (like mid & lower Csp (C3-7))
Mid & lower thoracic: variable
Rotation refers to the direction that the anterior vertebral body turns toward
C3-7 SIMILAR TO THORACIC
Lumbar vertebral column
Flat superior & inferior ends of vertebral bodies
Almost sagittal orientation of zygapophysial joints
(curved anteriorly)
6. Mammillary process: Located on the superior articular process
1. Accessory process: Located on the dorsal, medial aspect of the transverse process
L1-4 PARALLEL VB
Lumbar vertebral column - 2
Almost sagittal orientation of zygapophysial joints favour movements in the sagittal plane (F/E)
Changes to coronal by L5 to help prevent forward slipping of L5 on S1
L4 TRANSITION STAGE
L5-SUP. ARTICULAR PROCESS IS NOW MAJORITY IN CORONAL PLANE
The lumbar lordosis
• 1. sacrum is tilted anteriorly • 2. L5/S1 iv disc is wedge shaped (taller anteriorly) • 3. L5 vertebra similarly wedge shaped • 4. superior vertebrae incline slightly backwards • 5. L1 aligned vertically over S1 Flexion of the lumbar spine = decrease of the lordosis
Iliolumbar ligament:
- Transverse processes of L5 to ilium
- Resists L5 slipping anteriorly off the sacrum
- Resists all directions of movement of L5 on the sacrum
Movements of the Lumbar vertebral column
FLEXION limited by:
FLEXION limited by: 1. impaction of articular processes 2. tension in: • Zygapophysial joint capsules • Supraspinous ligament • Interspinous ligament • Ligamentum flavum • Posterior annulus fibrosus 3. compression of: • Anterior annulus fibrosus
- flx - lifting inf. articular processes up = allows a bit of rotation b4 impact, therefore transfer load on ligaments, disc and AF
Movements of the Lumbar vertebral column
AXIAL ROTATION limited by:
AXIAL ROTATION limited by:
- Impaction of zygapophysial joints
- Tension in posterior ligaments
- Tension in annulus fibrosus
* more rotation range in flexion
Movements of the Lumbar vertebral column
EXTENSION limited by:
- impaction of spinous processes or inferior articular process with lamina below
- Tension in anterior AF
Scoliosis
“3D torsional deformity of the spine & trunk” lateral curvature + axial rotation + disturbance of sagittal curves structural (true) v’s functional (extrinsic cause) Structural: 80% idiopathic Classification: age of onset Cobb angle: 100; 300; 500 location of frontal plane deformity R thoracic scoliosis R rib hump Rotation of the vertebra moves the ribs
- flattening of lordosis or kyphosis
lft lat flexion = R lat rotation
Segmental muscles
Interspinales (Cx / Lx) / medial intertransversarii (Cx)
Small PCSA
Small moment arms
= small force production Proprioceptive function?
“all unisegmental muscles of the vertebral column have between 2 to 6 times the density of muscle spindles found in the longer polysegmental muscles”
Note
intertransversarii (lateral) are not intrinsic back muscles – they are innervated by ventral rami
transversospinales
attach to inferior transverse processes & superior spinous processes
Rotatores:
brevis & longus
most developed in Tx region but still very small PCSA = proprioceptive?
Multifidus:
more oblique alignment in Tx … better line of action for segmental rotation & lateral flexion than in lumbar region
most developed in lumbar spine
Semispinalis:
most developed in cervical & capitis regions
= main cervical extensors
(semispinalis thoracis spinous attachment C7 – T4)
Multifidus:
• View it as arising from the caudal edge of a lamina / spinous process
• 3 to 5 fascicles diverge inferiorly & attach to:
• superior articular process Cx
• base of transverse process Tx
• mammillary processes Lx, iliac crest & sacrum (depending on the region)
* fascicles diverge
* don’t consider as rotator
Action of multifidus: Acts over few segments
Lateral view:
• Vertical line of action & posterior position to axis = posterior sagittal rotation i.e. extension
(& maintains the lumbar lordosis)
= no translation results from contraction
