applied anatomy and clinical syndromes Flashcards
SIJ function
Load transmission
Downward from head, trunk and upper limbs to lower limbs
Upward from ground reaction forces
Counterbalanced at symphysis pubis
Shock absorption
Protecting impact forces reaching Lumbar spine
Degeneration of SIJ higher incidence lumbar disc degeneration (Wilder et al 1980)
Childbirth: temporary increase joint laxity / movement –> lower sacrum rotates posteriorly (nutates) during childbirth
increase pelvic outlet
Load transfer
Pelvic Ring
Sacrum = keystone
decrease = direction of BW force from trunk to femurs
increase = direction of force from femurs to trunk
joint features
Diarthrodial joint Synovial fluid Articular surfaces covered with hyaline cartilage – Sacral > iliac Normally asymmetrical! At birth – surfaces flat Puberty – roughened & irregular (M>F)
Fibrous capsule – reinforced by ligaments
Innervation from L2 – S4
ligaments
sacroiliac joint
intersseous sacroiliac ligament
angulation of sacrum - faced forward and down
gravity drawing it forward
iliolumbar ligament
sacrospinal ligament
sacrotuberal ligament
sacroiliac ligament
palaption of long dorsal ligament - palpate for pain
hamstrinig insertion on ischial tuberosity
SIJ stabilising ligaments PRIMARY Anterior sacroiliac ligament Interosseous ligament Short & long dorsal ligaments SECONDARY Sacrotuberous ligament Sacrospinous ligament
pelvic / SIJ stability
hamstrings and ischial tub
tighten hamstring helps with tail of sacrum and helps it not to be drawn forward by gravity
self- locking mechanism of the pelvis
Form Closure = a stable situation where joint surfaces are closely fitting and no extra forces are required to maintain stability.
Shape of articular surface
Friction coefficient of articular cartilage
Integrity of joint ligaments
Force Closure = external forces (muscular & ligamentous) required for stability; increasing articular compressionincreasing articular co-efficient joint can better resist translation.
mechanism of pelvic stability
adding external forces makes joint stiffer and better to resist translation movement
Active SLR
TESTING
Lumbo-pelvic structures ability to transfer load
Core muscle control
TEST: (+) Pain / difficulty inability to SLR
Pt scores feeling of impairment (on both sides separately) on a 6-point scale:
not difficult at all= 0; minimally difficult= 1; somewhat difficult = 2; fairly difficult = 3; very difficult = 4; unable to do = 5.
Add B/L scores so that the sum score can range from 0 to 10
ADD FORM CLOSURE ADD FORCE CLOSURE
Better Better
ISQ ISQ
Worse
muscle control
No prime movers!
Stabilisers =
Transversus Abd (Richardson et al 2002)
Multifidus
Biceps femoris: continuous with Sacrotuberous ligt
Oblique slings: load transference during rotational activities
Gluteus maximus: contraction Sacrotuberous ligt tension
Contralateral Latissimus dorsi
SIJ kinematics
Mean rotational movements: 2-4° Nutation & Counternutation Mean translational movements: 1-2mm >3mm in nulliparous women Controversy over axes of movement: Flexion / extension Rotation Sideflexion
sacral nutation
Nutation = anterior sacral-on-iliac rotation
OR
posterior ilium-on-sacrum rotation
OR
both
Trunk forward bendingsacral counternutation
Counternutation = posterior sacral-on-iliac rotation
OR
anterior ilium-on-sacrum rotation
OR
both
Trunk bending back ?functional movements
TRUNK FLEX / EXT
Bilateral SIJ movmt
Flexion:
Sacrum nutates - 60°
Interosseous ligts / Sacrotuberous ligt taut
Articular ridges resist
Occ counternutates EOR
Bilateral anterior innominate rotn (on femora)
Extension:
Sacrum counternutates?
Long dorsal ligament taut
Pelvis relatively more unstable in counternutation
Bilateral posterior innominate rotn (on femora)
HIP FLEX / EXT
Unilateral SIJ movmt
Flexion:
Posterior innominate rotn = sacral nutation
Extension:
Anterior innominate rotn = sacrum counternutates
What does this look like unilaterally?
possible causes of SIJ pain
Trauma & Degeneration Pelvic # Arthrosis – often contralateral to hip OA Osteitis condensans ilii Ligamentous / Muscular sprain Inflammatory AS Psoriatic arthritis etc. Mechanical dysfunction Hypermobility Hypomobility Combination Pelvic asymmetry Sacral torsion / rotation
Innominate Upslip / Downslip Innominate Rotation Anterior Posterior Metabolic Osteoporosis Paget’s Disease Infections Tumours Piriformis Syndrome Referral from Lumbar Spine / Viscera Pregnancy Pelvic Girdle Pain (20%) LBP (88-96%)
pelvic girdle pain
Normally = 30yrs old
Pain experienced between the posterior iliac crest and the gluteal fold, particularly in the vicinity of the SIJ. The pain may radiate in the posterior thigh and can also occur in conjunction with/or separately in the symphysis. Pelvic girdle pain generally arises in relation to pregnancy, trauma and osteoarthritis.
Endurance capacity for standing, walking, and sitting is diminished.
Diagnosis of PGP can be reached after exclusion of lumbar causes, using battery of tests.
Pain or functional disturbances in relation to PGP must be reproducible by specific clinical tests.
asymmetric laxity of the SIJ during pregnancy 3X higher risk of moderate to severe pelvic pain persisting into the post partum period compared with symmetric laxity during pregnancy Damen et al 2002
Point prevalence of PGP in pregnancy = 20%
COST European
aim of physical exam of SIJ
Answer 3 questions:
Is SIJ the source of nociception?
PSIS / buttock is very common referral area for lumbar / hip problems. PSIS may even be tender on palpation due to pain referral.
Aggravating factors = loading pelvis
(+) pain provocation tests on manual exam
Are SIJs moving normally?
small but important movement
absence can lead to dysfunction in hip &/ LxSp and vice versa.
Is Pelvis symmetrical? interpret with care
Innominates on sacrum
Sacrum
