Week 9 - Lumbopelvic Sacrum Part 1 Flashcards
What are the 4 primary functions of the pelvis?
- Bear Weight
- Transfer loads from axial skeleton to appendicular (peripheral) skeleton
- Provide a stable base with limited mobility which leads to more efficient transfer of loads
- Serve as strong attachment point for muscles
Match the gender difference pelvic structure with the correct gender:
Prominent Bony Features
a) Male
b) Female
a) Male
Match the gender difference pelvic structure with the correct gender:
Narrow, heart shaped pelvic inlet
a) Male
b) Female
a) Male
Match the gender difference pelvic structure with the correct gender:
Less prominent or more rounded bony features
a) Male
b) Female
b) Female
Match the gender difference pelvic structure with the correct gender:
Laterally Facing Acetabulum
a) Male
b) Female
a) Male
Match the gender difference pelvic structure with the correct gender:
Wide, oval pelvic inlet
a) Male
b) Female
b) Female
Match the gender difference pelvic structure with the correct gender:
Wide distance between ASIS and ischial tuberosities
a) Male
b) Female
b) Female
Match the gender difference pelvic structure with the correct gender:
Narrow pubic arch (70 deg)
a) Male
b) Female
a) Male
Match the gender difference pelvic structure with the correct gender:
Anteriorly facing acetabulum
a) Male
b) Female
b) Female
Match the gender difference pelvic structure with the correct gender:
Wide pubic arch (90-100 degrees)
a) Male
b) Female
b) Female
What implication does the acetabulum orientation have between genders?
Different mechanics in gait
What is the implication of ichial tuberosity on males?
closer together - smaller base of support for males in sitting
(might be why males are sitting back on sacrum vs. females who perch up on ischial tuberositys when sitting)
What implication does muscle insertion have between genders?
Different moment arms, length-tension relationship for musculature
Why does the pelvis have the primary role of force transmission from the axial skeleton to the appendicular skeleton?
part of this is because of the muscular attachment that is has (i.e. pelvis to femur muscles, lumbar spine to pelvis)
Because of all its muscle attachments, what does the pelvis have in terms of influence on?
pelvis has large influence on trunk, hip, and knee
Because of its muscle attachments to the trunk, hip and knee, what is the pelvis aide in?
transmission of loads
What does the position of the pelvis influence in terms of muscles?
position influences length/tension relationships of muscles
What are the primary muscles for maintaining frontal plane stability during unilateral stance?
Right Hip Abductors (primarily gluteus medius)
How does gluteus medius act on the hip?
right hip abductors act on the pelvis to pull it into right lateral tilt
What contralteral muscles also act on the pelvis to pull into right lateral tilt?
Left Lumbar Erector Spinae (essentially force couple)
What is Lumbopelvic Rhythm?
Couples motion between pelvis and lumbar spine.
What effect does Lumbopelvic Rhythm have and when can it be observed?
Can increase overall trunk motion for function, observed in standing flexion and extension.
When a person is returning to stand from a flexed position, the first 25% is dominated by
pelvis and hip motion
When a person is returning to stand from a flexed position, the final 25% is dominated by
lumbar motion
At the early stages of extension from flexion, motion is dominated by the ____.
pelvis and hip
L/Hip Ratio 0.26, 0.61, 0.81
At the end of extension from flexion, motion is dominated by the ___.
lumbar spine
___ dominates during early phase
hip
___ increase during middle phase
Lumbar Spine
___ is primary during final phase
Lumbar Spine
LBP patients moved (earlier/later) to the lumbar spine early on (1st 25% of movment)
earlier
Had decrease contribution of the pelvis and hip and more contribution from the lumbar spine.
LBP patients had (looser/tighter) hamstrings (no correlation with LP Rhythm)
tighter
less mechanical constraint and more motor control issue
How do the contributions of extension from flexion compare to forward flexion?
Very similar only reversed
___ dominates early flexion
lumbar spine
___ dominates late flexion
hip
Typical extensor recruitment strategy is (caudal to cephalic / cephalic to caudal) in healthy people
caudal to cephalic
People who develop low back pain during standing had a ___ muscle recruitment strategy
reversed (cephalic to caudal)
NPD/PD demonstrated ___ recruitment strategies.
opposite (bottom-up vs. top-down)
T/F: A patient may experience altered movement PRIOR to pain development
True
There is potential for altered loading at the vertebral joint level with early activation of ___
errector spinae
What do we look for in terms of dynamic postures and movement (3)
- Quantity - Range of motion in all planes
- Quality
- Willingness to Move
What do we look at when checking for Aberrant Movement Patters in the Sagittal Plane? (3)
- Lumbopelvic Rhythm
- Gower’s Sign
- Instability Catch
During reversal of lumbopelvic rhythm what does the patient do, what does the therapist observe, and what is typical?
Patient asked to bend forward as far as they can (standing flexion) and return to upright posture.
Therapist observes relative timing and sequence of trunk/pelvis motion.
Typical: Trunk moves first in flexion, last in extension. Pelvis moves last in flexion, first in Extension.
What is Gower’s Sign also known as?
‘Thigh Climbing’
During Gower’s Sign what does the patient do, and what is a positive sign?
Patient asked to bend forward as far as they can (standing flexion) and then return to upright.
Sign is positive if they must use their hands on their thighs to assist with return to standing position. (generally not due to weakness but pain)
During Instability Catch Sign, what does the patient do, and what is a positive sign?
Patient asked to bend forward as far as they can (standing flexion) and return to upright posture (same as reverse lumbopelvic rhythm).
Sign is positive if they cannot return to erect posture due to sudden painful ‘catch’ in their low back. (again pain, thought to indicate ‘spinal instability’)
How is interrater reliability for Reversal of Lumbopelvic Rhythm, Gowers Sign, and Instability Catch.
Reversal of Lumbopelvic Rhythm: Poor (k = .16)
Gower Sign: 98% agreement between clinicians
Instability Catch: Poor (k=.25)
If you combines all tests, how is interrater reliability for Aberrant Movement Patterns in General?
A little bit better at K= .6
The top of the sacrum is called the ___
base (or promontory)
The bottom of the sacrum is called the ___
apex
What is the base (sacral promontory formed by?
1st Sacral Vertebra
How many facets does the Sacral base have, what direction do they face, and what do they articulate with?
2 facets that face posteriorly and articulate with the inferior facets of the 5th lumbar vertebrae
What is the L5-S1 joint also called?
lumbosacral joint
What is the apex formed by?
5th Sacral vertebrae
What does the sacral apex articulate with?
coccyx
What are the lateral regions of the sacrum also referred to as?
Ala
Describe the lateral region of the sacrum and what it articulates with?
Ear shaped articular surface that articulates with the ilium
What joint does the sacrum form with the ilium?
sacroiliac joint
Is the sacroiliac joint a soft or rigid articulation?
rigid
What are the two surfaces that articulate in the sacroiliac joint known as?
Auricular Surface of Sacrum and Auricular Surface of ilium
Where does controversy lie with the sacroiliac joint?
in the amount of motion that occurs at this joint
Is making a diagnosis of sacroiliac joint disorder easy or difficult?
Difficult because don’t know amount of motion
What is the function of the sacroiliac joint? (4)
- Weight bearing joint
- Relieve stress (in pelvis region)
- Load Transfer from spine to pelvis
- Stability around lumbosacral region and pelvis and hips
Where does majority of extensibility in the SI joint primarily come from?
Extensive network of ligaments
What are the Primary Ligaments that stabilize the SI joint and where can they be viewed? (4)
- Anterior Sacroiliac Ligament (anterior)
- Iliolumbar Ligament (posterior)
- Interosseous Ligament (anterior)
- Posterior Sacroiliac Ligament (posterior)
What are the two Secondary Ligaments of the SI? (2)
- Sacrotuberous Ligament
2. Sacrospinous Ligament
What is thought the be the range of motion at the SI joint?
~1-4 degrees of rotation (SMALL)
~1-3 mm of translation
(more like arthrokinematic ROM than osteokinematic)
What are the two terms used to describe rotational and translational movements at the SI Joint?
- Nutation
2. Counternutation
What can nutation be thought of as?
‘Forward Nod’ of Sacrum or Anterior Sacral Tilt
What are the motions of the sacrum (both base and apex) during Nutation? How does the innominate move?
- Sacrum moves relative to innominate or pelvis bones.
- Base moves anteriorly/inferiorly
- Apex moves posteriorly/superiorly
Innominate moves in opposite motion: relative posterior pelvic tilt
What can counternutation be thought of as?
‘Backward Nod’ of Sacrum or Posterior Sacral Tilt
What are the motions of the sacrum (both base and apex) during Counternutation? How does the innominate move?
- Movement of the sacrum relative to the innominate
- Base moves posteriorly/superiorly
- Apex moves anteriorly
Innominate moves in opposite motion: relative anterior pelvic tilt
During bilateral hip extension in prone, you are describing the direction of the sacrum relative to
the innominate bones.
During bilateral hip extension while in the prone position,the sacrum moves in a ____ position relative to the innominate bones. The innominates bones move in a ___ relative to the sacrum.
counternutated (backward nodding)
anterior pelvic tilt
(increasing lordosis)
What is the importance of nutation and counter nutation illustrating small movements that occur at the SI joint?
Movments provide “stress relief” within the pelvis, important for functional activities including walking, running, and childbirth.
Nutation at the SI joints increases ____
congruence between the joint surfaces of the sacrum and innominant bones
What effect does nutation increasing joint congruance have? (3)
- Increase Articular Stability (joint surfaces)
- Optimizes transference of load
- Ligaments (sacrotuberous and interosseous) get support from the muscles
Which position is the most stable for the SI joint?
The nutation position, full nutation is considered to be closed pack position for this joint.
What contributes to nutation torque?
body weight vector and hip joint compression vector
What contribution do the body weight vector and hip joint compression vector have in nutation?
Body Weight Vector: pulls the sacrum into an anterior rotated or nutation position
Hip Joint Compression Vector: acts to pull the pelvis into a posterior tilt
Which stretched ligaments play a stabilizing role in nutation?
Interosseous ligament and Sacrotuberous ligament become taught?
What muscles contribute to nutation torque?
Errector Spinae: Act directly on sacrum to pull it further into anterior tilt or nutated position
Rectus Abdominus and Biceps Femoris: Act on pelvis to pull it into a relative posterior pelvic tilt relative to the sacrum
