Biomechanics

Question 1

Motion Segment of the spine consists of what?

Answer 1

a disc, 2 vertebral bodies, 2 facet joints and surrounding soft tissues

Question 2

Anterior longitudinal ligament attaches to more what than what?

Answer 2

more bodies than disc

Question 3

Posterior Longitudinal Ligament attaches to what?

Answer 3

the discs and is responsible for preventing posterior disc protrusion; it is highly innervated and can cause pain

Question 4

Ligamentum Flavum

Answer 4

80% elastin 20% collagen, allows flexion; loses elasticity in elderly and can cause pressure on nerve root

Question 5

Supraspinous Ligament is what?

Answer 5

the most superficial and most susceptible to injury

Question 6

Iliolumbar ligament limits motion where?

Answer 6

The L4-L5 segment and sacrum and ileum. Can be source of pain from innervation

Question 7

2 main functions of the spine

Answer 7

provides mobility and stability

Question 8

Cervical facet joints oriented how?

Answer 8

45 degrees from horizontal; allows some rotation and translation

Question 9

Thoracic Facets oriented how?

Answer 9

coronal plane which allows rotation but not forward displacement/translation

Question 10

Lumbar Facets oriented how?

Answer 10

saggital plane allow a/p translation and resists rotation; no rotation or side bending serves to protect the disc

Question 11

Segmental Spinal motions

Answer 11

planar- flexion/extension
coupled- sidebend/rotation
compression/distraction

Question 12

Flexion and extension of the segment is based on what?

Answer 12

the superior segment

Question 13

rotation of segment is based on the movement of what?

Answer 13

anterior vertebral body

Question 14

During flexion the facets glide how?

Answer 14

superiorly and anterior; causes anterior sagittal rotation and translation; opens the foramen but is limited by posterior ligaments and bony contact from facet joint orientation

Question 15

While flexing the spine what tightens to switch off back extensors?

Answer 15

thoracolumbar fascia tightens to shut off muscles and prevent compression on facet joint and vertebral body; passive support is from ligaments of spine

Question 16

If someone is having pain with flexion what would their clinical implications be?

Answer 16

inflamed facet joints, posterior disc herniation, muscle spasms, or strained posterior ligament, acute nerve injury; repetitive bending causes disc and other soft tissue injuries

Question 17

During extension the facets glide?

Answer 17

posteriorly and inferiorly with posterior sagittal oration and minimal posterior translation; this closes the facets and narrows the foramen

Question 18

extension is limited by what?

Answer 18

approximation of spinous processes and muscle contribution form back extensors and abs working eccentrically

Question 19

If someone is having pain with extension what are their clinical implications?

Answer 19

OA of facet joints, stenosis, Z-joints compressed with repetitive extension; in sports repetitive extension can cause pars interarticularis fx

Question 20

What are limiters to rotation?

Answer 20

closing of the contralateral facet and stretching of the ipsilateral facet capsule

Question 21

The disc tears the annulus at how many degrees of rotation?

Answer 21

8-10

Question 22

Rotation is best for what clinically?

Answer 22

the best stimulus for annulus of disc regeneration when done in pain free range; also opens lateral foramen

Question 23

During side flexion the facets?

Answer 23

the ipsilateral facet glides inferiorly and contralateral superiorly; the facets can only slide up and down

Question 24

In a NEUTRAL spine, coupled motions of the CS, TS, and LS are what?

Answer 24

CS: SB and rotation same
TS: same side unless at TL junction
LS: SB and rotation occur opposite

Question 25

Fryettes Law of Coupled motion with a flexed and extended LS?

Answer 25

In flexion and extension, sidebending and rotation of the LB occur to the SAME side