III. Biomechanics of the Lumbar Spine Flashcards

1
Q

What are common sources for low back pain?

A

disc facet joints soft tissue

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

What are the major functions of the lumbar spine?

A

support for trunk and upper extremities resist compression provide mobility muscular attachment protect the spinal cord/cauda equina

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

How does the width of the lumbar vertebrae change from above down?

A

width increases

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

what kind of curve does the lumbar spine form?

A

lordotic

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

What is the normal lumbar lordosis angle?

A

40-60 degrees

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

What is the normal lumbosacral angle?

A

26-57 degrees

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

What is the shape of a lumbar vertebral body?

A

kidney

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

Are lumbar vertebral bodies wider side to side or A to P?

A

side to side

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

What is the approximate height of an IVD in the lumbar region?

A

9mm

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

What percentage of spinal height is attributed to IVD height?

A

25%

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

What is the ration of IVD to vertebral body height in cervical region?

A

2 : 5

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

What is the ration of IVD to vertebral body height in thoracic region?

A

1:5

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

What is the ration of IVD to vertebral body height in lumbar region?

A

1:3

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

The large disc to vertebral body height ratio seen in the lumbar region attributes to what?

A

increased lumbar flexibility

increased shock absorption

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

Nucleus puplosus is located where in the disc?

A

posterior 1/3

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

What causes the nucleus pulposus to become mobile?

A

annular tearing

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

How much possible height variation may occur in a person throughout the day due to IVD hydration/dehydration?

A

3/4”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How much possible height loss may occur in a person due to normal IVD aging?

A

1 inch

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

What plane are the articular fects of the lumbar spine in?

A

mostly sagittal but becoming more coronal at L5

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

Which articular facet surface in the lumbar region is convex, superior or inferior?

A

inferior

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

Which articular facet surface in the lumbar region is concave, superior or inferior?

A

superior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which articular facets face inferiorly, laterally and anteriorly in the lumbar region, superior or inferior?

A

inferior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which articular facets face superiorly, medially and posteriorly in the lumbar region, superior or inferior?

A

superior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where is the most common site for facet asymmetry (facetal tropism)?

A

lumbar region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What kind of motion do the lumbar facets facilitate and what motion do the lumbar facets resist?

A

facilitate flexion and extension

resist rotation and lateral flexion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Asymmetrical facets (facetal tropism) can cause what?

A

increased cartilage wear, increased disc stress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Facets carry what percentage of the spine’s axial load?

A

3-25%, depending on anatomy and posture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Facets carry what percentage of the spine’s axial load when in extended posture?

A

up to 33%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Facets and their articular cpasules provide what percentage of the torsional strength of the lumbar spine?

A

up to 45%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Describe the TPs of the lumbar region?

A

small and run posterolaterally

site of muscle and ligament attachment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe the SPs of the lumbar region?

A

fewer anomalies than in the thoracics

run horizontal (no sloping as in thoracics)

large and hatchet shaped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Describe the SP of L5?

A

shorter and rounder than the rest of the lumbar vertebrae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Where would you palpate for mamillary processes?

A

in the lumbar region, lateral to the interspinous space above the corresponding SP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Describe the vertebral end plates in the thoracic and lumbar spine?

A

made of thin cortical bone

lined with hyaline cartilage

outer rim is ossified around age 14-15

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

The possibility of permanent correction of scoliosis dereases after what event?

A

ossification of the rim of the vertebral end plates at age 14-15

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is Wolff’s law?

A

ossification in mature bone is in proportion to the stress on the bone

more stress/pressure = more bone growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is Heuter Volkman’s law?

A

increased pressure across an epiphyseal growth plate of immature bone, inhibits growth

more pressure/stress = less growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How does Heuter Volkman’s law explain idiopathic scoliosis?

A

Increased pressure causes decreased bone growth which decreased pressure causes increased bone growth which makes vertebrae develop wedge shape. This causes concavity on the high pressure side and covexity on the low pressure side as pictured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are Schmorl’s nodes?

A

herniations of the nucleus pulposus through the vertebral end plates

40
Q

What is Scheuermann’s disease?

A

idiopathic process of unknown etiology that effects ossification of the outer rim of the end plate resulting in:

  • vertebral wedging (decreased anterior vertebral height)
  • rough end plates
  • schmorl’s nodes

increased kyphosis

41
Q

What muscles are relevant in the biomechanics of the lumbar spine?

A
  • transversospinales (multifidus, rotatores)
  • quadratus lumborum
  • psoas major
  • iliocostalis lumborum
  • abdominal muscles
  • intertransversarii
  • interspinous
42
Q

What ligaments are relevant in the biomechanics of the lumbar spine?

A
  • ALL
  • PLL
  • ligamentum flavum
  • capsular ligaments
  • iliolumbar ligaments
  • interspinours ligaments
  • supraspinous ligaments

intertransverse ligaments

-transforaminal ligaments

43
Q

What is the normal global ROM for flexion in the lumbar spine?

A

40-60 degrees (excluding hip flexion)

44
Q

What is the normal global ROM for extension in the lumbar spine?

A

20-35 degrees

45
Q

What is the normal global ROM for rotation in the lumbar spine?

A

5-18 degrees

46
Q

Approximately what percentage of overall trunk flexion occurs in the lumbar spine?

A

75%

47
Q

Flexion increases in what part of the lumbar spine?

A

increases superior to inferior

i.e. less flexion at L1 and more at L5

48
Q

Where is the IAR of flexion in the lumbar spine?

A

anterior disc

49
Q

What is the pattern of motion around the IAR in flexion of the lumbar spine?

A

forward tilting with anterior translation

i.e. +z and +θx

50
Q

orthogonal description of lumbar flexion?

A

+θx

positive rotation about the X axis

51
Q

orthogonal description of lumbar extension?

A

-θx

negative rotation about the X-axis

52
Q

Extension increases in what part of the lumbar spine?

A

increases superior to inferior

i.e. less extension at L1, more at L5

53
Q

Where is the IAR of extension in the lumbar spine?

A

posterior disc

54
Q

What is the pattern of motion around the IAR in extension of the lumbar spine?

A

backward tilting with posterior translation

NOTE: posterior translation accentuated with DJD

55
Q

What is the segmental motion for rotation of L5 in the lumbar spine?

A

5 degrees (compared to 1-2 degrees in L1-L4)

56
Q

What is the segmental motion for rotation of L1-L4 in the lumbar spine?

A

1-2 degrees (compared to 5 degrees of L5)

57
Q

What allows for more segemental rotation but less lateral flexion at L5 than L1-L4 ?

A

Facets are sagittal L1-L4

Facets are more coronal L5

58
Q

Where is the IAR of rotation in the lumbar region?

A

posterior annulus on the contralateral side

59
Q

What is the pattern of motion around the IAR in rotation of the lumbar spine?

A

rotation around the y-axis

+θy for right lateral flexion

-θy for left lateral flexion

60
Q

What is the normal global ROM for lateral flexion in the lumbar spine?

A

15-25 degrees

61
Q

What is the segmental motion for lateral flexion of L1-L4 in the lumbar spine?

A

5-8 degrees per segment (compared to 2-3 degrees for L5)

62
Q

What is the segmental motion for rotation of L5 in the lumbar spine?

A

2-3 degrees per segment (compared to 5-8 degrees for L1-4)

63
Q

Where is the IAR of lateral flexion in the lumbar region?

A

contralateral disc

i.e. right lateral flexion will have IAR on the left side of disc

64
Q

What is the pattern of motion around the IAR in lateral flexion of the lumbar spine?

A

There is some controversy/lack of consensus over this but:

  • if lumbar spine starts neutral or extended and then lateral flexes, there is contralateral coupled rotation.
  • if the lubar spine starts flexed and then lateral flexes, there is ipsilateral couple rotation
65
Q

What kind of contraction is occuring when a muscle shortens and muscle tension overcomes resistance?

A

concentric muslce contraction

66
Q

What kind of contraction is occuring when a muscle elongates and resistance overcomes muscle tension?

A

eccentric contraction

67
Q

What does lumbopelvic rhythm describe?

A

the expected sequence of events in the lumbar spine, pelvis and hips as a person flexes and returns to normal

68
Q

What initiates lumbopelvic flexion and what controls motion once gravity takes over?

A
  • concentric contraction of psoas and abdominals initiates
  • eccentric contraction of erector spinae muscles control motion once gravity takes over
69
Q

In the first 60 degrees of lumbopelvic flexion, where is the motion?

A

only the lumbar spine because pelvis is locked in place by gluteus maximus and hamstrings

70
Q

After the first 60 degrees of lumbopelvic flexion, where is the motion?

A

the pelvis because the stabilizing forces of glut max and hamstrings has been overcome and the pelvis rotatates another 25-30 degrees

71
Q

When returning to neutral from a flexed lumbopalvis, where does the motion start?

A

the pelvis moves first under control of the hip extensors, followed by extension of the lumbar spine controlled by erector spinae muscles

72
Q

What ligaments limit lumbopelvic flexion?

A

ligamentum flavum

PLL
capsular ligaments

interspinal ligaments

73
Q

What initiates lumbopelvic extension and what controls motion once gravity takes over?

A
  • concentric contraction of the sacrospinalis (erector spinae) initiates
  • eccentric contraction of abdominal muscles control motion once gravity takes over
74
Q

What ligaments limit lumbopelvic extension?

A

ALL

anterior annulus

75
Q

Other than ligaments, what is the most significant limiter of lumbopelvic extension?

A

spinous processes

76
Q

What initiates lumbopelvic lateral flexion and what controls motion once gravity takes over?

A

concentric contraction of ipsilateral quadratus lumborum initiates lateral flexion

eccentric contraction of contralateral quadratus lumborum controls motion once gravity takes over

77
Q

What ligaments limit lumbopelvic lateral flexion?

A

capsular ligmants

ligamentum flavum

intertransverse ligaments

deep lumbar fascia on contralateral side

78
Q

Approximation of the ipsilateral articular facets limits what lumbopelvic motion?

A

lateral flexion

79
Q

What initiates lumbopelvic rotation and what controls motion?

A
  • concentric contraction of ipsilateral internal obliques and contralateral external obliques (some contribution from rotatores and multifidus on contralateral side)
  • Eccentric contractions of the ipsilateral rotatores and multifidus control motion
80
Q

What ligaments limit lumbopelvic rotation?

A

capsular ligaments

interspinous ligaments

ligamentum flavum

81
Q

Other than ligaments, lumbopelvic rotation is mainly limited by what?

A

facetal design

82
Q

What is the normal global ROM for lumbopelvic flexion?

A

90 degrees

83
Q

What is the normal global ROM for lumbopelvic extension?

A

25-30 degrees

84
Q

What is the normal global ROM for lumbopelvic lateral flexion?

A

15-25 degrees

85
Q

What is the normal global ROM for lumbopelvic rotation?

A

45 degrees

86
Q

examination of the lumbar spine could include:

A

postural exam

global ROM evaluation

static palpation

motion palpation

X-ray evaluation

orthopedic testing

neurologic testing

87
Q

What is Type I lumbar motion?

A

normal, SP rotation into concavity with lateral flexion

88
Q

What is type II lumbar motion?

A

abnormal, early dysfunction in which SP rotates into convexity with lateral flexion

89
Q

What is type III lumbar motion?

A

abnormal, loss of lateral flexion

90
Q

What is type IV lumbar motion?

A

abnormal, loss of flexion and rotation

91
Q

What is facet syndrome?

A

mechanical, degenerative or traumatic derangement of posterior joints?

92
Q

What is the affect of facet tropism?

A

increased stress to the joints and more prone to facet syndrome

93
Q

What is IVD syndrome?

A

annular tearing, fissuring that causes pain, derangements, joint locking and/or joint restrictions

94
Q

What is interdiscal block?

A

nuclear material migrating into the fissures causing pain, derangements, joint locking and/or joint restrictions

95
Q

What is a disc herniation?

A

disc bulge or protrusion caused by extrusion of the nucleus into the canal (usually still contained in annulus)

96
Q
A