Lumbar Part 2

Question 1

Trunk Flexion
First gravity initiates

Answer 1

movement

Question 2

Trunk flexion part 2
Erector spinae contract ______, assisted by

Answer 2

eccentrically
thoracolumbar fascia and posterior ligaments

Question 3

Trunk Flexion part 3
after about 2/3 of flexion, erector spinae are

Answer 3

relaxed

Question 4

Trunk flexion part 4
What controls the movement after muscles relax?

Answer 4

ligaments

Question 5

Trunk Extension
What initiates trunk extension from a fully flexed position?

Answer 5

pelvis extends on hips

Question 6

Trunk Extension
Which muscles initiate the motion and which muscles help complete the motion?

Answer 6

Initiate: Glute max
Complete: Erector spinae

Question 7

Trunk Extension
Which joints extend first, and which joints help complete the motion?

Answer 7

Pelvis extends first
facet joints complete motion

Question 8

What happens to the erector spinae moment arm as the pelvis posteriorly tilts

Answer 8

decreases as it becomes parallel with body

Question 9

Trunk Extension
Explain why hip extensors contracting first helps limit stress on the lumbar spine & erector spinae

Answer 9

they move the moment arm of the bodyweight from perpendicular to parallel, lessening stress on the erector spinae

Question 10

Lumbopelvic Rhythm
Exact degrees of motion for spine and hips/pelvis is variable, however in most adults it is usually:
Forward Flxion of trunk:
About 45 deg is
About 60 deg is

Answer 10

45: thoracolumbar spine flexion
60: anterior tilting of pelvis by rotation of pelvis on femoral head (flexion of hips)

Question 11

Extension of trunk from forward flexed position:
About 60 deg is:
About 45 deg is:

Answer 11

60: posterior tilting of pelvis by rotation of pelvis on femoral heads (extension of hips)
45: thoracolumbar spine flexion

Question 12

What are the benefits of lumbopelvic rhythm

Answer 12

decreases stress on lumbar spine and erector spinae

Question 13

Can you explain why a patient with back pain may exhibit Gowers Sign?

Answer 13

hypomobility —> more stress on ligaments

erector spinae weakness

Question 14

Anterior pelvic tilt accentuates

Answer 14

lumbar lordosis

Question 15

Which muscles are contracting in anterior pelvic tilt

Answer 15

Rectus femoris and iliopsoas

Question 16

What is the effect of a full anterior pelvic tilt on the intervertebral foramen and nucleus pulposis?

Answer 16

less space in IV foramen

nucleus pushed anteriorly

Question 17

Posterior pelvic tilt reduces

Answer 17

lumbar lordosis

Question 18

Which muscles are contracting in posterior pelvic tilt

Answer 18

abs (rectus)
also glute max

Question 19

What is the effect of a full posterior pelvic tilt on the intervertebral foramen and nucleus pulposis?

Answer 19

More space in foramen

nucleus pushed posteriorly

Question 20

Greatly exaggerated lumbar lordosis (“lordotic posture”)
Which muscles may be weak?
Which muscles may be tight

Answer 20

weak: abs/glute max
tight: hip flexors

Question 21

Greatly exaggerated lumbar lordosis (“lordotic posture”)
Which joints have increased compressive forces
Effect on nucleus pulposis?

Answer 21

Facets
nucleus pushed anteriorly

Question 22

Greatly exaggerated lumbar lordosis (“lordotic posture”)
Increased shearing forces - favors development of

Answer 22

spondylolisthesis

Question 23

Decreased lumbar lordosis (“flat back posture”)
Which muscles are weak?
Tight?

Answer 23

weak: hip flexors/erectors
tight: abs/glutes

Question 24

Decreased lumbar lordosis (“flat back posture”)
Which joints have increased compressive forces?
Effect on nucleus

Answer 24

intervertebral body joints (compressed)
Nucleus pushed posteriorly

Question 25

Tight Hip flexors affect on lumbar lordosis

Answer 25

excessive anterior tilt —> increased lordosis

Question 26

Superficial Layer
Bilateral activation

Answer 26

extends the adjacent region of the trunk

Question 27

Superficial Layer
Unilateral activation causes

Answer 27

lateral flexion and rotation of the region of the spine

Question 28

Intermediate layers
_____ muscles
minimal effect on ______
Mostly involved with ______

Answer 28

thin muscles
trunk motion
breathing

Question 29

• Spinalis muscles: small, may be

Answer 29

indistinct or missing

Question 30

Longissimus muscles: largest and most

Answer 30

developed part of the erector spinae

Question 31

Iliocostalis muscles: most ____ part of the erector spinae

Answer 31

lateral

Question 32

The bulk of the erector spinae muscles have a common attachment on a broad and thick “common tendon” that attaches to the

Answer 32

sacrum

Question 33

Bilateral contraction of erector spinae

Answer 33

Extension of lumbar spine
anterior tilt of pelvis

Question 34

Unilateral contraction
Iliocostalis can

Answer 34

laterally flex the trunk

Question 35

Unilateral contraction:
Iliocostalis lumborum assists slightly with

Answer 35

ipsilateral axial rotation

Question 36

The primary function of the trunk transversospinal muscles is to produce

Answer 36

relatively fine controlled movements of the spine and provide stabilizing forces in the axial skeleton

Question 37

Transversospinal muscles
Semispinalis crosses

Answer 37

6 to 8 intervertebral junctions

Question 38

Transversospinal Muscles
Multifidi: originate from transverse process of one vertebra and insert on

Answer 38

spinous process of vertebra 2 to 4 intervertebral junctions above

Question 39

Transversospinal Muscles
Rotatores: deepest, from transverse process to base of

Answer 39

spinous process 1 to 2 intervertebral junctions above

Question 40

Short Segmental Trunk Muscles

Answer 40

Interspinalis muscles
Intertransversarius muscles