How is the SI joint classified?
part synovial and part syndesmosis
What is the function of the SI joint?
link between the axial skeleton and the LE thus transmits forces from the axial skeleton to the lowerlimbs and vice versa
What muscles contribute to the stability of the SI joint
quadratus lumborum, multifidus, erector spinae, gluteus minimus, piriformis, iliacus, and latisimus dorsi, internal and external oblique, rectus abdominis, transversus abdominis
How much motion occurs at the SI joint
1-3 mm or 1-3 degrees
What artery bifurcates just anterior to the sacrum?
common iliac artery
Pelvic girdle disorders clasification from an impairment based model?
1) hypmobility 2) hypermobility 3) normal mobility with pain
MOI for SIJ
posterior torsion with heavy lifting, falls on the iscial tuberosity, vertical thrust on the extended leg, and persistent postures (single leg stance in bowling) kicks the miss the ball Anterior torsion: golf swing and horizontal thrust on the knee with the hip flexed (MVA) Repetitive strain: secondary to decrease flexibility with gait
Describe the pain referral of SI joint
Fortin's area which is just inferior to the PSIS is about 3-10 cm
Is limitation in lumbar ROM an indicator of SI dysfunction?
What pain provocation tests have been found to be the most useful in terms of reliability, sensitivity, specificity, and validity?
Compression, distraction, (POSH) thigh thrust, FABER, resisted hip abd, sacral shear, Gaselen's
SIJ laxity can be identified with what test?
What can cause pain with normal SI mobility?
mild sprain, strain, inflammatory disease, or overuse of the adjacent articular or myofascial structures
What common medical conditions affect the SI joint?
Anylosing spondylitis, Reiter Syndrome, inflammatory bowel disease, psoriatic spondylitis, RA, infection, tuberculosis
What are radiographic signs of pubic symphysis instability
>10mm seperation,>2 mm vertical displacement with single leg stance