Anatomy & Physiology - Spine & SI Flashcards

1
Q

Pars interarticularis

A

part of the lamina - area of thick cortical bone bridging the superior and inferior articular processes

IMPORTANT for transmitting load from POST to ANT

Susceptible to stress and compression fx
(spondylolysis–>listhesis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Anterior Longitudinal Ligament

A

anterior to vertebral bodies from sacrum to C2

  • attaches segmentally to VERTEBRAL BODIES
  • FUNCTION = resist extension

susceptible to hyperextension trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Posterior Longitudinal LIgament

A

runs posterior to vertebral bodies and continuous w/ tectorial membrane at C2

  • attaches segmentally to DISC in fan-like pattern
  • innervated by sinuvertebral nerve (same that innervates 1/3 of outer annulus of disc)
  • FUNCTION: prevent posterior disc protrusion and segmental restraint to flexion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Ligamentum Flavum

A

connects two consecutive lamina

-attaches to anterior part of facet joint and becomes the joint capsule

FUNCTION: allow flexion to a certain extent & limit flexion
–> if it loses elasticity over time it may buckle & cause compression on nerve root

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Interspinous LIgament

A

segmental attachment of spinous processes

innervated by medial branch of posterior (dorsal) rami

FUNCTION: assist w/ segmental stability, prevent seperation of two s.p’s during flexion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Supraspinous Ligament

A

runs along the length of the spinous processes w/ segmental attachments via transverse fibers

  • greatest risk of injury b/c furthest from axis of motion

most developed in the lumbar region

FUNCTION: resist flexion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Iliolumbar Ligament

A

attaches bodies of L4/L5 to ilium

FUNCTION: limit motion in lumbosacral region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does a motion segment consist of?

A

a disc, two vertebral bodies, 2 facet joints and surrounding soft tissue

Superior vertebrae defines direction of movement
Rotation is defined by anterior part of vertebral body (not the direction of the spinous process)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Facet Joint Orientation

A

CS = 45deg to horizontal
- allows rotation, flex/ext

TS = coronal
- allow for rotation, prevents forward translation

LS = sagittal
- allow for flex/ext & resist rotation

L5/S1 = coronal

Greatest rotation = horizontal,
then coronal
Least = sagittal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Fryette’s Law - Lumbar Spine

A

Side bending and rotation are coupled in OPPOSITE directions

Neutral spine = SB & ROT - OPP
Flexed spine = SB & ROT - SAME
Extended spine = SB & ROT - SAME

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Erector Spinae

A

FUNCTION - back extension (main) + anterior tiliting + minimal stabilization of LS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Interspinalis & Intertransversarii

A

FUNCTION: fine tune segmental motion & provide proprioceptive feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Quadratus Lumborum

A

FUNCTION: lumbopelvic motion, especially rotation, side flexion, stabilizer in sustainted posture, stable base for diaphragm during inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Multifidus

A

FUNCTION: segmental stability & LS/SI stability

- controls anterior shear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Transverse Abdominus

A

FUNCTION: anticipate motion, provide segmental stability, prevent anterior shearing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Internal vs. External Oblique

A

Internal -
FUNCTION - anterior pelvic tilt, initiate L rotation
–> originates from ASIS & t-l fascia, which is why it does an anterior pelvic tilt b/c contraction of I.O tenses t-l fascia

External -
FUNCTION - posterior pelvic tilt, initiate R rotation
–> all anterior attachments, so contraction will cause a posterior pelvic tilt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Thoracolumbar Fascia

A

Spinous process of T12 to PSIS and iliac crests
- envelop lumbar muscles

FUNCTION:

  • attachment site
  • stabilize against anterior shear/flexion
  • “corset” action
  • transmission of extension forces
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Vertebral End-plate

A

cartilage above & below disc, tightly bound to disc

Highly innervated

Sharpy’s fibers: annulus fibers that insert onto vertebral body

FUNCTION: hold disc in place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Nucleus Pulposus

A

mainly water allowing for deformation under compression
(contains proteoglycans which hold water)

TYPE II collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Annulus fibrosus

A

Type I Collagen that hold the nucleus pulposus in place
- Lamella: bundles of sheath around nucleus arranged in alternating diagonal patterns

Posterior fibers are thinner to allow for flexion, also a common site for posterior disc protrusions

HIGHLY innervated (outer 1/3) by sinuvertebral nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Disc Mechanics (5)

A
  1. Compression (normal)
    - WB activities and muscle contraction
    - equilibrium between push & pull
  2. Distraction (normal)
    - separation of vertebral bodies
  3. Rocking (normal or pathological)
    - bending the disc anterior & posterior
  4. Rotation (pathological)
    - half of annulus on slack & other half on stretch
  5. Shear (pathological)
    - MOST DETRIMENTAL to disc
    - takes place w/ rotation (lateral shearing)
22
Q

Lumbosacral Joint

A

L4, L5 and S1 - facets oriented in CORONAL plane and coupling of SB & ROT to the same side (diff from LS)

L5/S1 = primary WB joint

Motion restricted by iliolumbar ligament - especially excessive sacral flexion

23
Q

5 joints of lumbopelvic region

A
  1. lumbosacral
  2. sacroiliac (x2)
  3. pubic symphysis
  4. hip joints (x2)
  5. coccyx
24
Q

Sacroiliac Joints

- joint surfaces

A

Sacrum: Inverted L shape

  • Short arm (superior) = depth of sacrum - in vertical plane
  • Long arm (inferior) = length of sacrum w/n S2/S3 in A-P plane

Ilium: corresponding L shape

25
SI Joints | - FUNCTION
transfer load from trunk to legs and absorb/dissipate forces from LE before they reach the spine Major WB joint (as well as L5/S1)
26
SI Joint Stability (4 things)
1. Articulating surfaces - sacral surface has thick hyaline cartilage - ilial surface has fibrocartilage 2. Two joint stypes - anterior (1/3 of joint) = synovial - posterior (2/3 of joint) = syndesmosis - held together by interosseus membrane which allows for very little motion 3. Joint surfaces un-smooth (friction) 4. Extensive ligaments
27
Anterior SI ligament
WEAKEST and most susceptible to injury FUNCTION: limit anterior gapping test w/ anterior distraction
28
Posterior Interosseus Ligament
deepest and STRONGEST FUNCTION: limit posterior gapping test w/ anterior compression
29
Long dorsal (posterior) SI ligament
connects PSIS to lateral segments of S3 and S4 FUNCTION: prevent counternutation (backward tiliting) blends w/ multifidus, ES, and t-l fascia which is why those structures are important for the stability of the SI joint
30
Sacrotuberous ligament
attaches PIIS medially down to S3 and S4 and to ischial tuberosity FUNCTION: prevent nutation blends w/ biceps femoris tendon so contraction of this muscle will increase stability of SI joint by increasing tension in ligament
31
Sacrospinous ligament
attaches ischial spine to lateral margins of the sacrum & coccyx FUNCTION: prevent nutation blends to form capsule of the SIJ
32
Muscles of the Pelvic Girdle | - inner vs outer
Inner tube = local muscles (TrA, multifidus, diaphragm and pelvic floor muscles) Outer = global muscles (4 systems - longitudinal, anterior & posterior oblique, and lateral) Piriformis - only muscle w/ direct attachment to SIJ - function = ER - can cause SI problems Biceps femoris attaches to sacrotuberous ligament so can cause counternutation of sacrum or prevent nutation
33
Sacroiliac Biomechanics
Sacrum moving on ilium during LUMBAR motions Flexion = sacral nutation then counternutation Extension = sacral counternutation Axial rotation = reciprocal motion of unilateral ipsilateral nutation and counternutation (picture hypothetical oblique axis) ``` Nutation = sacrum gliding anterior & inferior Counternutation = posterior & superior ```
34
Iliosacral Biomechanics
Ilium moving on the sacrum during HIP motions ``` Flexion = posterior rotation Extension = anterior rotation ```
35
Longitudinal System - outer tube muscles of the pelvic girdle
Erector spinae t-l fascia biceps femoris (sacrotuberus ligament)
36
Anterior oblique system - outer tube muscles of pelvic girdle
Internal and external obliques abdominal fascia contralateral adductors
37
Posterior oblique system - outer tube muscles of pelvic girdle
Latissimus dorsi Contralateral glute max t-l fascia
38
Lateral system - outer tube muscles of the pelvic girdle
Glute med & min | contralateral adductors
39
Lumbar Spine flexion - facet motion - limiters - mechanics - clinical implication
- Facets glide superior - opens foramen & facet joints - Limited by: PLL, LF, ISL, SSL (all posterior ligaments), tension on post part of disc, bony block - Mechanics: initiated by abdominals, then "flexion-relaxation phenomenon" - TLF stretches, deactivating the ES to prevent overactivation - Clinical implication: repetitive flexion can cause disc injuries, avoid w/ certain diagnoses (usually during acute stage)
40
Lumbar Spine Extension - facet motion - limiters - Mechanics - Clinical implication
- Facets glides inferior - closes facets & narrows foramen - Limited by: approximation of spinous processes or facet joints - Mechanics: initiated & maintained by back extensors while abdominals work eccentrically - Clinical Implication: avoid w/ stenosis, OA of facet joints, excessive lordosis - -> excessive loading on pars interarticularis common during hyperextension & sporting activities - -> repetitive extension can damage facet joints
41
Lumbar Spine Rotation - facet motion - limiters - clinical implication
- Ipsilateral facets move inferior (caudal) and contralateral facets glide superior (cranial) - LS = gapping on ipsilateral side - CS = gapping on contralateral side - Limited by: approximation of contralateral facet, stretch of joint capsule or disc rotation - Clinical implication: optimal stimulus IF w/n pain-free, optimal range, rotational manual therapy due to opening of lateral foramen (LS - same side)
42
Lumbar Spine Side Flexion - facet motion - coupled w/?
- Ipsilateral facet glides inferior (caudal) and contralateral facet glides superior (cranial) - Fryette's Law = SB & ROT of LS are coupled in opposite directions UNLESS... - spine is flexed or extended then coupled in SAME direction
43
Upper CS Biomechanics - Flexion & Extension
Flexion - occipital condyles glide posterior - C1 moves inferior - C2 translates anterior Extension - occipital condyles glide anterior - C1 moves superior - C2 translates posterior on C3
44
Upper CS Biomechanics - SB
- occipital condyle glides anterior | - nothing at AA?
45
Upper CS Biomechanics - Rotation
50% of cervical rotation comes from C1-C2! The AA joint is the "no" joint - occipital condyles glide posterior - C1 translates to opposite side - ipsilateral facet glides posterior - CL facet glides anterior
46
Upper CS Motion Coupling
SB & Rotation occur in OPPOSITE directions when you have SB to the right you will have a rotation to the left - can use to differentiate between UCS vs. LCS problems
47
Lower CS Biomechanics - Flexion/Extension
Flexion - vertebral body translates anterior - Facets glide anterior Extension - vertebral body translates posterior - Facets glide posterior
48
Lower CS Biomechanics - SB/ROT | - Coupled motion
SB - ipsilateral facet glides inferior - CL facet glides superior Rotation is same biomechanics because in LCS coupled motion, SB and rotation occur in the SAME direction - when you SB to the left it gaps the right foramen, when you rotate to the left, it will also gap the right foramen
49
Thoracic Spine Biomechanics - Flex/Ext
Flexion - vertebral body translates anterior Extension - vertebral body translates posterior Motion increases in the LOWER SEGMENTS
50
Rib Biomechanics - Flex/Ext
Flexion - anterior rib translates inferior - posterior rib translates superior - plus ANT rotation Extension - anterior rib translates superior - posterior rib translates inferior - plus POST rotation
51
Thoracic Spine Biomechanics - SB/ROT
- ipsilateral facet extends (inferior-lateral) - CL facet flexes (superior-medial) Coupled motion - SB & rotation of the TS occur in the SAME direction - CTJ and TLJ will follow respective biomechanics
52
Rib Biomechanics - SB/ROT
- ipsilateral rib translates inferior and rotates posterior | - CL rib translates superior and rotates anterior