Lumbopelvic Manipulation

Why is the SI joint (SIJ) an important area of study?

The SI joint is often ignored by some health care professionals - current research is showing that SI dysfunction is clinically important (separate from other low back problems)

What is SI pain typically described as by a patient?

Low back pain

What joints make up the anatomy of the pelvis?

Three Joint Complex - Sacroiliac joints and pubic symphysis

Describe the joint surface of the SIJ

Atypical - create a diarthrosis

What is a diarthrosis?

True synovial joint with joint cavity, synovial fluid and joint capsule

What kind of joint is the pubic symphysis?

Amphiarthrosis- contains an interpubic fibrocartilaginous disc

What is the shape of the SIJ?

L shape/boot shape

Where does the upper part of the SIJ articulate?

At the level of S1

Where does the lower part of the SIJ articulate?

At the level of S2-S3

What sacral surface segments contribute to the SIJ?

S1-S3

What is found on the sacral surface of the SIJ?

Hyaline cartilage - blue color and found three times thicker than iliac surface

Describe the morphology of the sacral surface of the SIJ

• Central groove (concavity)

• Wedge shaped superior to inferior

• S-shape anterior to posterior

What is found on the surface of the iliac that makes up the SIJ?

Fibrocartilage - yellow color

Describe the surface of the iliac surface making up the SIJ

Central convex ridge

What is the large rough bony surface on the iliac surface posterior and superior to the SI joint for ligamentous attachment?

Iliac tuberosity

Describe the state of the pelvis at birth

Joints undeveloped, smooth and flat, glide in any direction; stability provided by ligaments - begin to develop during walking

Describe the state of the pelvis in teen years

Roughening of surfaces, development of grooves and ridges - male more pronounced than female

What develops in the pelvis as a teenager?

Track bound movement (tram & rail)

Describe the state of the pelvis in the 3rd and 4th decase

Articular changes in surface anatomy are well established and joint surfaces become more irregular - involes enlargement of iliac tuberosity and depression

What may start to develop in the pelvis in the 3rd and 4th decades?

Joint surface erosions and possible osteoarthrosis (DJD) on iliac surface (more in males)

Describe the state of the pelvis in the 5th and 6th decades

Joint surfaces become more irregular - each individual joint is unique in its topography to varying degrees (more pronounced in males)

What may develop in the pelvis during the 5th and 6th decades?

Possible osteoarthrosis (DJD) developing on sacral surface and continuing on iliac surface (more in males) and possible development of joint adhesions, osteophytes, and fusion

Describe the state of the pelvis in the 7th decade

Interarticular adhesions with a high prevalence of bony ankylosis (fusion)

What is the development of bony ankylosis (fusion) dependent on?

Gender and age in AMAB

How likely is an AMAB to develop bony ankylosis (fusion)?

27.7%

How likely is an AFAB to develop bony ankylosis (fusion)?

2.3%

How likely is an AMAB between the ages 20-39 to develop bony ankylosis (fusion)?

5.7%

How likely is an AMAB between the ages 60-79 to develop bony ankylosis (fusion)?

31.1%

How likely is an AMAB over the age of 80 to develop bony ankylosis (fusion)?

46.7%

What structures bind the sacrum to the ilium, limit movement and provide significant support?

Intrinsic SI Ligaments

What are the different groups of intrinsic SI ligaments?

Posterior sacroiliac ligaments, anterior sacroiliac ligaments and the joint capsule

What are the posterior SI ligaments?

Interosseous and dorsal ligaments

What posterior SI ligament is the massive, major posterior stabilizer?

Interosseous

What posterior SI ligament is smaller, not as critical to joint stability found between the sacrum, the PSIS and iliac tuberosityr?

Dorsal ligaments

What is the function of the dorsal ligaments?

Limits anterior movement of the sacral base (nutation)

What runs between the interosseous and posterior sacroiliac ligaments?

Dorsal rami

What intrinsic SI ligament is a thin; thickening of the anterior joint capsule?

Anterior sacroiliac ligament

What intrinsic SI ligament is well developed anteriorly, not posteriorly?

Joint capsule

What are the extrinsic ligaments in the pelvis?

• Sacrotuberous

• Sacrospinous

What extrinsic SI ligament is from the inferior portion of the sacrum to the ischial tuberosity?

Sacrotuberous

What is the function of the sacrotuberous ligament?

Limits posterior movement of the sacral apex

What extrinsic SI ligament is from the inferior lateral edge of the sacrum and the upper edge of the coccyx to the ischial spine?

Sacrospinous

What is the function of the sacrospinous ligament?

Limits posterior movement of the sacral apex

Describe the symphysis pubis

Amphiarthrosis, interpubic fibrocartilaginous disc

What muscles act on the SI joint?

No muscles act on the SI joint directly because none cross the joint, though many may influence the mechanical behavior of the joint or respond to stresses applied to it

What muscles may load the SI joint?

• Erector spinae

• Quadratus lumborum

• Psoas

• Iliacus

• Piriformis

• Gluteals

How do muscles contribute to SIJ dysfunction?

Muscles can react to SI stress causing spasms, trigger points - abnormal muscle tension may limit overall SI movement leading to joint dysfunction

How is the SIJ innervated?

Debated - but neural elements have been identified in the joint capsule and adjoining ligaments suggesting innervation for both pain and proprioception

What biomechanics of the pelvis contribute to the supporting the trunk and resisting downward shear?

The keystone effect and the self locking mechanism

What is created because the sacrum forms the keystone of an arch suspended by strong sacroiliac ligaments?

Keystone effects

Due to the keystone effect, what movement is resisted by the wedge shaped sacrum?

Inferior displacement

Due to the keystone effect, what movement is resisted by the sacroiliac ligaments?

Posterior displacement

Due to the keystone effect, what movement is resisted by the sacroiliac ligaments and pubic symphysis?

Anterior displacement

What makes up the self-locking mechanism in the biomechanics of the pelvis?

Form closure and force closure

What part of the self-locking mechanism uses the anatomy of the SI joints to promote stability?

Form closure

What contributes to form closure of the self-locking mechanism?

• Wedge shape of the sacrum

• Interlocking groove (sacrum) and ridge (ilium)

• S-shaped joint surfaces

What part of the self locking mechanism is related to the tension in muscles, ligaments and thoracolumbar fascia that aids in stabilizing the SI joints?

Force closure

What contributes to force closure in the self locking mechanism?

• Creates lateral to medial pressure from the ilia to the sacrum, compressing the SI joints

• Clutch-like bracing system with on-demand tightening and loosening system to increase stability of the SI joints when needed

What are both form and force closure important for?

Maintaining SI stability and function

What is the dynamic role of the pelvis?

Transmit forces between lower extremity and axial skeleton, acting as a shock absorber

How does the pelvis act as a shock absorber during locomotion?

Slides and pivots to absorb and adapt to forces generated between trunk and lower extremity

Where does stress decrease in the body as the pelvis acts as a shock absorber?

Lumbar spine and opposite side SI joint

What is known about sacroiliac kinematics?

Movement is present but precise pattern remains unclear - many theories and models, but difficult to establish one consistent model of SI motion due to limited research, individual variation and relatively small amount of total motion

What joint in the pelvis has the exact amount of movement debated, but most agree that it is relatively small?

Sacroliliac - most research suggests around 2–4° of total flexion and extension

What happens to movement in the SIJ with age?

Decreases - especially in men

How does range of motion for the SI differ between genders?

Greater in females

What is the predominant plane of motion of the SI?

Around the x-axis in the semi-sagittal plane (track bound) - axis of rotation is speculative but most commonly placed posterior to the joint around the iliac tuberosity

What are the characteristics of SI motion?

• Coupled and dependent to some degree on joint separation

• Not uniform between individuals

• Greatest during locomotion

Why is motion of the SI not uniform between individuals?

Developmental changes in surface architecture

What is the basis of Illi’s model of locomotion?

Most influential model - describes the reciprocal motion between the ilium and sacrum

What accompanies flexion of the hip and ilium (posterior inferior movement of the PSIS) in Illi's model of locomotion?

Ipsilateral anterior inferior movement of the sacral base (SI flexion)

What accompanies extension of the hip and ilium (anterior superior movement of the PSIS) in Illi's model of locomotion?

Ipsilateral posterior superior movement of the sacral base (SI extension)

Under Illi's model of locomotion what does motion lead to?

Complex movement of circumduction (gyroscopic) of the sacrum between the ilium - oblique and horizontal figure-8 is the resulting movement of the sacrum

How is Illi's model of locomotion correlated to palpation?

Gillet’s test attempts to evaluate SI motions that occur during locomotion

How is SI motion named?

According to how the ilium moves relative to the sacrum - apply the terms “flexion” and “extension” to SI joint movement or ilium position, not the movement or position of the sacrum

What terms should be used when talking about the sacrum?

“nutation” and “counternutation”

What does anterior inferior movement of the sacral base (nutation) create in the lumbosacral region?

Extension - relative to the ilium it creates SI flexion

What does posterior superior movement of the sacral base (counter nutation) create in the lumbosacral region?

Flexion - relative to the ilium it creates SI extension

What movements are created by the pubic symphysis?

• Gliding (shear) compression and separation

• Rotation in the sagittal plane with flexion/extension of SI joints

Why are pubic symphysis kinematics important to the SI?

May play role in SI dysfunction

What are the steps in the physical evaluation of the lumbar spine and pelvis while the patient is standing?

Inspection, global ROM, SI motion palpation

What is the inspected superficially in the physical evaluation of the lumbar spine and pelvis?

Observe skin and bony landmarks

What is inspected “posturally” in the physical evaluation of the lumbar spine and pelvis?

• iliac crest height

• greater trochanters

• gluteal folds

• spinal curves

• anterior/posterior pelvic tilt

What is being assessed for GROM?

Range, quality, and pain

How is GROM assessed in the physical evaluation of the lumbar spine and pelvis?

• bend forward to touch toes, extend backwards

• lateral bending, running fingers down the side of leg

• trunk rotation

• inclinometry

What is used to assess SI motion palpation?

Screening tests and flexion/extension evaluation via Gillet’s test

What screening test is performed to screen SI motion palpation?

Piedau’s test - standing or sitting

Describe the normal findings of Piedau’s test

Separation of PSIS and sacral apex should occur when patient flexes forward indicating that the sacral base has moved posteriorly relative to the ilia - if PSIS’s start even, they should separate slightly as the sacral base moves posterior and superior

Based on Piedau’s test, where is dysfunction suspected?

On the side where the PSIS starts inferior and ends up superior

Describe hypomobility found with an assessment using Piedau’s test

SI joint not free to glide, ilium must move further to make up for lack of SI motion

What does Gillet’s tests assess?

Flexion/extension

What are the methods for Gillet’s test?

• bent knee or straight leg methods

• evaluate upper and lower portions of the joint

• if bent, must go above 90° of hip flexion for extension tests

What are the steps of a prone physical evaluation of the lumbar spine and pelvis?

Observation, static palpation, motion palpation, leg length evaluation

What is assessed in static palpation for the physical evaluation of the lumbar spine and pelvis?

Soft tissue and bony palpation

What is being assessed for soft tissue palpation of the lumbar spine and pelvis?

• skin temperature and sensitivity

• tenderness and texture of lumbar and pelvis region muscles and ligaments - start superficially and work deeper

What is being assessed for bony palpation of the lumbar spine and pelvis?

• alignment of SP’s, iliac crests, PSIS’s, sacral base, sacral apex

• tenderness of bony landmarks and interspinous spaces - possible allodynia

What is allodynia?

Pain produced by normally painless stimuli

What is the possible sign with a painful SP palpation?

Underlying joint dysfunction or abnormality

What motion palpations are assessed in the prone position for the lumbars?

P-A, rotation, lateral flexion

What motion palpations are assessed in the prone position for the SI?

SI joint provocations - flexion & extension