Vertebral Column III

Question 1

what is the primary cause of thoracic kyphosis?

Answer 1

bc of the wedge shaped vertebrae

Question 2

what limits the following movements in the thoracic region: overall movement, tilt, flexion + extension?

Answer 2

• presence of rib cage reduces overall movement
• intervertebral disc doesn’t facilitate movement bc it isn’t very high (so superior vertebrae cannot tilt as much)
• tall, coronal superior articular processes limit flexion + extension
• long, inferior sloping spinous processes limit extension

Question 3

describe the coupling movements in the thoracic region for upper thoracic and mid + lower thoracic?

Answer 3

upper thoracic: lateral flexion + rotation ipsilateral coupling- when the inferior articular process of the superior vertebrae slides inferiorly it also moves posteriorly (like mid and lower Csp)
mid + lower thoracic: variable (varies amongst the vertebrae)

Question 4

describe the 5 points of lumbar lordosis

Answer 4

1. sacrum is tilted anteriorly
2. L5/S1 IV disc is wedge shaped (taller anteriorly)
3. L5 vertebrae similarly wedge shaped
4. superior vertebrae incline slightly backwards
5. L1 aligned vertically over S1

Question 5

what are the attachments of the iliolumbar ligament?

Answer 5

transverse process of L5 to ilium

Question 6

what does the iliolumbar ligament resist?

Answer 6

resists L5 slipping anteriorly off the sacrum; resists all directions of movements of L5 on the sacrum

Question 7

what are the passive and active structures that stabilise L5 and S1 articulation?

Answer 7

z joint, overlapping of the articular processes, iliolumbar ligament, longitudinal ligament, intervertebral disc, muscles

Question 8

in the lumbar vertebral column, what is flexion limited by?

Answer 8

• impaction of anterior articular processes (main restraint)
• tension in z joint capsule, supraspinous ligament, interspinous ligament, ligamentum flavum, posterior annulus fibrosus
• compression in anterior annulus fibrosus

Question 9

in the lumbar vertebral column, what is extension limited by?

Answer 9

(all equally contribute)

• compression of interspinous ligament
• impaction of spinous processes or inferior articular process with lamina below
• tension in anterior annulus fibrosus

Question 10

in the lumbar vertebral column, what is axial rotation limited by?

Answer 10

• impaction of z joint
• tension in posterior ligaments
• tension in annulus fibrosus

Question 11

what does repetitive hyperextension produce?

Answer 11

pars interarticularis

Question 12

what is spondylolysis?

Answer 12

defect in the pars interarticularis

Question 13

what is spondylolisthesis?

Answer 13

forward translation of the superior vertebrae on the inferior vertebrae

Question 14

what is scoliosis?

Answer 14

3D torsional deformity of the spine and trunk: lateral curvature + axial rotation + disturbance of sagittal curves

Question 15

what is the intrinsic back muscles innervated by?

Answer 15

dorsal rami

Question 16

what muscles are in the suboccipital group?

Answer 16

rectus capitis posterior minor, rectus capitis posterior major, obliquus capitis superior, obliquus capitis inferior

Question 17

what muscles are in the segmental group?

Answer 17

interspinales, intertransversales

Question 18

what muscles are in the transversospinales group?

Answer 18

spinalis, longissimus, iliocostalis

Question 19

what muscle is in the spinotransverse group?

Answer 19

splenius

Question 20

describe the PSCA, moment arm and force production of the segmental muscles?

Answer 20

small PCSA, small moment arms= small force production

Question 21

describe the actions of the lumbar multifidus from a lateral view and posterior view

Answer 21

lateral view- vertical line of action + posterior position to axis = posterior sagittal rotation -> lumbar extension and maintains the lumbar lordosis
posterior view- small horizontal component that could assist rotation (in Tx) but you have external oblique abdominals, minimal segmental rotation in lumbar region

Question 22

describe the unilateral and bilateral action of the longissimus thoracis pars thoracis & iliocostalis lumborum pars thoracis

Answer 22

unilateral action- ipsilateral lateral flexion

bilateral action- extension

Question 23

describe the line of action, PCSA and moment of longissimus thoracis pars thoracis & iliocostalis lumborum pars thoracis

Answer 23

vertical line of action, large PCSA, larger posterior moment arm (most powerful extensors of the lumbar spine)

Question 24

describe the unilateral and bilateral action of the longissimus thoracis pars lumborum & iliocostalis lumborum pars lumborum

Answer 24

unilateral action- vertical line of action lateral to the axis= lateral flexor
bilateral action- vertical line of action posterior to the axis (posterior sagittal rotation i.e. extension); horizontal line of action (+ simultaneous posterior sheer- or resit anterior sheer)

Question 25

describe the anterior & posterior shear forces on the lumbar spine

Answer 25

when lumbar spine flexes, the superior body weight exerts compressive and anterior shear force on the intervertebral joints. Mechanisms to stabilise the motion segment: zygapophyseal joints/articular processes, intervertebral disc, ligaments, muscles

Question 26

what does the medial branch of the dorsal rami innervate?

Answer 26

zygapophysial joints above + below, all muscles arising from spinous process/lamina of the vertebrae = interspinales, rotatores, multifidus and semispinalis (+ cutaneous branch in Cx and upper Tx)

Question 27

what does the intermediate branch of the dorsal rami innervate?

Answer 27

longissimus

Question 28

what does the lateral branch of the dorsal rami innervate?

Answer 28

erectore spinae + cutaneous branch in lower Tx and Lx