5 - SI Joint Examination and Treatment

anterior aspect of the SIJ

two innominants with the pubic symphysis, forming a ring

posterior aspect of the SIJ

wedge shaped sacrum

Auricular (ear shaped) surface forms

rough, irregular joint to increase fibrous connection and stability

Interarticular fibrous connections form with...

age (more stiff)

Movement of SIJ

deformations and slight gliding motions

SIJ - degrees of rotation

0.2 - 2 degrees

SIJ - amount of translation available

1 - 2mm

nutation is associated with

increased lumbar lordosis and extension

counternutation is associated with

decreased lumbar lordosis and flexion

Nutation - sacral tilt

anterior (superior aspect nods ant and inferior)

Nutation - iliac tilt

posterior

what posture increases nutation?

standing

Counternutation - sacral tilt

posterior and superior

Counternutation - iliac tilt

anterior

what position favors counternutation?

supine --> risk

Closed packed position of SIJ

Nutation

Loose packed position of SIJ

Counternutation

anterior ligamentous reinforcements of SIJ

comparatively weak

- resists anterior distraction and nutation

Interosseous ligament

strong, short, deep to dorsal ligament

posterior or Dorsal SIJ ligaments

- strong w/ multidirectional fibers

- palpable caudal to PSIS

Posterior/dorsal ligaments resists

counternutation

the posterior/dorsal ligaments attach to what 3 things? what is it continuous with?

- attach to: erector spinae, multifidi, thoracodorsal fascia

- inferiorly cont. w sacrotuberous ligament

extra-articular ligamentous support (2)

- sacrotuberous

- sacrospinous

Sacrotuberous ligament bony attachments

- lateral sacrum

- PSIS

- ischial tuberosity

sacrotuberous ligament - muscle attachments

- gluteus maximus

- piriformis

- continuous with biceps femoris

sacrotuberous resists what movement?

nutation and cranial (superior) migration

sacrospinous ligament attachments

lateral sacrum to spine of ischium

sacrospinous resists what movement?

nutation

Pubic symphysis

far from AOR at SIJ

Pubic symphysis is supported by

anterior, inferior, posterior and superior ligaments

pubic symphysis - type of pain

common source of groin pain

what muscles attach to both innominates and sacrum? (3)

- piriformis

- gluteus maximus

- iliacus

other muscles of interest for SIJ

- erector spinae

- multifidi

- Bicep femoris LH

- Transverse abd

- internal/external obliques

Glute max arises from (5)

- innominate

- sacrum and coccyx

- aponeurosis of erector spinae

- superficial thoracodorsal fascia

- fascia of glut. Med

Glute max inserts on

gluteal tuberosity

Glute max ipsilaterally blends w/

multifidus via fascia

Glute max contralaterally blends w/

latissimus dorsi via fascia and sacrotuberous ligament

Form closure

stability of jt due solely to anatomy

- shape and congruency of joint surfaces

- integrity of ligaments

Force closure

Stability of joint due to dynamic interacting forces of gravity, ligamentous tension, fascial and muscle forces.

~ what we can alter as PTs

Active muscle force ~ force closure

- Erector spinae - pushes up posterior on sacrum

- Rectus abdominus pulls innominate up

- Active force counteracts and creates stability (self locking mechanism)

Train pts to facilitate muscles ~

- Abdominus, hamstrings, erector spinae - to get stability before doing torsional movements

- Exercises with hip ext while firing opposite erector spinae bc they have cross-fascial connection that stabilizes joints

All components create self locking mechanism in

force closure

What is key of in force closure in SIJ?

nutation of sacrum

- winds up ligaments, utilizes gravity favorably

muscles that assist in force closure (5)

- erector spinae

- rectus abdominus

- gluteus maximus

- latissimus dorsi

- bicep femoris

What reduces the self locking mechanism of SIJ?

counternutation

What position reduces the self locking mechanism of SIJ? (hint: counternutation) (3)

- end range forward bending

- sacral sitting

- long sitting

What can also result in counter nutation and reduce force closure, predisposing SI joint to injury?

Weakness or imbalance in lumbar/hip/pelvis region

In the absence of very clear diagnostic criteria: if lumbar or hip S/S are present

treat those first

When do you focus on treating SIJ?

after lumbar or hip S/S are resolved, if symptoms still present

MOJ for SIJ

- unilateral trauma (stepping down hard on one foor or falling on one hip/isch tub)

torsion results via

femur through acetabulum or isch tub

--> foundation of leg length discrepancy association w SIJ Patho

Typical SI joint Pain

Unilateral pain with no referral below knee

- sharp pain or catching during mvmt

- esp transitional mvmts (STS, rolling)

groin pain is often associated with...

pubic symphysis dysfunction

- may be related to SIJ

Typical aggravating factors of SIJ pain (6)

- Reciprocally going down stairs

- Getting in/out of cars

- Holding child on one hip

- Sitting with legs crossed (post tilt)

- Walking with long stride length

- Traditional positioning (missionary position)

- Anything that creates torsion

Chronic SIJ mechanisms of injury may be associated with

-Ligamentous laxity

-Asymmetrical Postures

Ligamentous laxity may be due to

Recent pregnancy/meds/cyclical symptoms

Asymmetrical Postures can be from

• Work postures

• Child care

Observations of SIJ dysfunction

Visual or palpable asymmetry

Functional Tests - palpate during these:

-Unilateral stance, IR/ER (like thessaly)

-Gillets (march)

-Forward Flexion

APR in sitting

pain free (if pelvis is stabilized and WB is symmetrical)

Palpation unique to SIJ

greater chance that pubic symphysis may be involved, far from AOR

Special tests for SIJ (6)

• Ganslens

• Gillet (March)

• Forward flexion

• Primary stress tests (anterior and posterior gapping)

• Fabers/Patrick

• Joint play (flutter)

Conditioning of SIJ, it is best to move from...

- bilateral to unilatereal

- symmetry to asymmetry

- opposire some lumbar progressions

- seated before standing

- opposite of exercise progression from disk

~ Strengthen muscles that control ant/post tilt of pelvis

~ Extensors, ab/adductors

Length and strength

Consider position in frontal + sagittal plane

SIJ treatment aims to reduce _____________ and increase ___________.

torsional forces initially; stability

- SIJ belt

what should be emphasized in treatment?

conditioning of muscles that maintain force closure AND core stability

- diagonal relationship of lats to glutes --> tensions TLF over SIJ (fascial connections)

what position should be encouraged for stability?

nutation

what shoudl be corrected during treatment?

correct length/strength deficiencies that undermine stability via imbalace or asymmetry