Thoracolumbar

Question 1

How are the zygapophyseal joints in the thoracic region aligned?

Answer 1

Coronal Orientation
‘Tall’ superior articular process
60-80 degrees to transverse plane (more vertical than cervical)

Question 2

What movements do the z-joints in the thoracic region allow?

Answer 2

Axial rotation and lateral flexion

Question 3

How are z-joints in the lumbar region aligned?

Answer 3

90 degrees to transverse with a sagittal plane orientation

Question 4

What movements do the z-joints in the lumbar region allow?

Answer 4

Flexion-Extension

Not so much axial rotation as the more vertical z joints ‘block’ the rotation

Question 5

Explain the mechanism causing a pars interarticularis defect

Answer 5

Defect in between articulating Z joints – lamina of vertebrae (collar of scotty dog)

Caused by repetitive hyperextension and axial loading = too much force going through pars interarticularis (inferior facet is ramming into superior facet)

Defect = fracture/weakening of bone tissue (spondylolysis)

Question 6

What is spondylolysis

Answer 6

breakdown of bone tissue at pars interarticularis

Question 7

What is spondylolisthesis

Answer 7

forward translation of superior vertebrae relative to the inferior vertebrae

isthmic spondylolisthesis occurs as a result of a pars interarticularis defect

Question 8

What ligaments provide stability to the Lumbosacral junction?

Answer 8

iliolumbar and lumbosacral ligament

Question 9

What is the function of the iliolumbar ligament?

Answer 9

Primary restraint of L5 moving on S1

Question 10

What is the function of the lumbosacral ligament?

Answer 10

Resist lumbosacral extension and Contralateral flexion

Question 11

What structure is superficial to lumbar multifidus?

Answer 11

Erector Spinae aponeurosis

Question 12

What structure innervates lumbar multifidus?

Answer 12

Medial branch of lumbar dorsal rami

Question 13

Explain the lumbar lordosis

Answer 13

Anterior tilt of sacrum
L5/S1 inervertebral disc and L5 vertebra are wedged shape and taller anteriorly
L1-L4 posterior tilt

Question 14

What is FLEXION in the lumbar region limited by?

Answer 14

impact anterior part of articular processes

tension in:
Zygapophysial joint capsules
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Posterior annulus fibrosus

compression of: Anterior annulus fibrosus

Question 15

What is EXTENSION in the Lumbar region limited by?

Answer 15

compression of interspinous ligament

impaction of spinous processes or inferior articular process with lamina below*

Tension in anterior Annulus Fibrosus

Question 16

What is AXIAL ROTATION in the Lumbar region limited by?

Answer 16

Impact on z joints
Tension in posterior ligaments
Tension in annulus fibrosus

Question 17

What is LATERAL FLEXION in the Lumbar region limited by?

Answer 17

Ligamentum Flavum

Question 18

Explain the Anterior and Posterior shear forces on the lumbar spine

Answer 18

When lumbar spine flexes, the superior body weight exerts compressive and anterior shear force on the intervertebral joints.

Question 19

What are the PRIME EXTENSORS of the trunk?

Answer 19

Longissimus thoracis pars thoracis

iliocostalis lumborum pars thoracis

Question 20

Why are the Longissimus thoracis pars thoracis and

Iliocostalis lumborum pars thoracis PRIME EXTENSORS?

Answer 20

Vertical line of action
Large PCSA
Large posterior moment arm

Question 21

How is the external flexion moment, generated by gravity acting on the mass of the trunk, resisted during trunk flexion from anatomical position?

Answer 21

Trunk supported by erector spinae, posterior intervertebral disc, interspinous and supraspinous ligaments, fascia

Initial active tension in the erector spinae relaxes at 75%-85% of trunk flexion as the connective tissue components of the muscle and posterior intervertebral discs and ligaments are tensed

Sacral nutation limited by: sacrospinous, sacrotuberous,
sacroiliac ligaments

Hip F limited by tension in: hamstrings - biceps femoris,
semimembranosus, semitendinosus

Question 22

What are some characteristics of the Lumbar intervertebral disc?

Answer 22

More proportion of Nucleus Pulposus
Wedged
Taller anteriorly