pelvic girdle clinical anatomy and syndromes Flashcards
(33 cards)
what are the functions of the sacro-iliac joint?
-load transmission from head, trunk, UL and LL
-shock absorption -protecting impact forces reaching lumbar spine
-child birth - there is a temporary in joint laxity and movement
describe the sacroiliac joint features
-diarthrodial joint (2 articulating surfaces)
-synovial fluid
-articular surfaces are covered with hyaline cartilage
-has a fibrous capsule
-innervated from L2-S4
ligaments of sacroiliac joint
what are the primary SIJ stabilising ligaments?
-anterior sacroiliac ligament
-interosseous ligaments
-short and long dorsal ligaments
what is the self locking mechanism of the pelvis?
refers to the way the pelvis stabilizes itself — especially at the sacroiliac (SI) joints — during activities like standing, walking, or lifting. It is a combination of the pelvis’s anatomical shape (form closure) and the muscle and ligament forces acting on it (force closure).
what is form closure?
a stable situation where joint surfaces are loosely fitting and no extra forces are required to maintain stability
what is force closure?
-external forces (muscular and ligaments) required for stability
what are the primary stabiliser muscles of the SIJ?
-transverse abdominus
-multifidus (deep muscles)
-biceps femoris (hamstring - sarcotuberous ligament)
-oblique slings: 2 muscles working together for load transference during rotational activities ie gluteus Maximus (on one side) + contralateral lat dorsi
is there much movement at the SIJ?
very small amount of movement
-some rotational, some translational, nutation (flexion) and counter nutation (extension) etc
what is sacral nutation?
-“flexion”
-forward tipping of the sacrum at the sacroiliac (SI) joints.
-or anterior sacral on iliac rotation
in what movements does sacral nutation mean?
Standing upright / standing on 1 leg
Loading the pelvis (like during lifting, jumping, or walking)
Childbirth (at certain stages, the sacrum nutates to widen parts of the pelvis)
what is sacral counternutation?
-extension of the sacrum
-the top of the sacrum (sacral base) moves posteriorly and superiorly (back and up), while the apex (the bottom tip of the sacrum) moves anteriorly and inferiorly (forward and down).
-posterior sacral on iliac rotation
what is innominate rotation?
The innominates are your two large pelvic bones (each made of the fused ilium, ischium, and pubis).
Innominate rotation refers to movement of one innominate bone (left or right) relative to the sacrum at the sacroiliac (SI) joint.
what happens in your SIJ during trunk flexion?
-sacrum nutates 60 degrees
-interosseous ligaments become taut
-articular ridges resist
-bilateral anterior innominate rotation
what are possible causes of SIJ pain and dysfunction?
- Trauma + degeneration
-pelvic fractures
-arthrosis
-ligament or muscle strain - inflammatory
-AS
-psoriatic arthritis - Mechanical dysfunction
-hypermobility
-hypomobility - pelvic asymmetry
-innominate rotation - anterior and posterior - metabolic
-OP - Referral from lumbar spine and viscera
- Pregnancy - pelvic girdle pain (20%) and LBP (88-96%)
what is pelvic girdle pain?
pain experienced between the posterior iliac crest and the gluteal fold, particularly in the SIJ.
-the pain may radiate in the posterior thigh and can occur in the symphysis
in what populations or scenarios does pelvic girdle pain arise in?
-pregnancy
-trauma
-OA
with pelvic girdle pain, how is endurance capacity with standing, walking etc affected?
it is diminished
what needs to be ruled out for diagnosis for pelvic girdle pain?
-after exclusion of lumbar causes and inclusion of PGP using battery of tests
-the pain / functional disturbances in relation to PGP must be reproducible by specific clinical tests
what’s an important point to note about laxity of the SIJ during pregnancy?
if there is asymmetric laxity of the SIJ, there is a 3x higher risk of moderate to severe pelvic pain persisting into the post part period compared to systematic laxity during pregnancy
what are the subjective findings of PGP?
-often unilateral pain
-usually younger person involved in sport eg dance, tennis, running
-pregnancy and childbirth related too
-pain aggravated by loading through SIJ - stairs, sit to stand, prolonged standing, turning in bed, getting in and out of bed, weight bearing phases in gait
what are risk factors for PGP antepartum (before birth)?
-prior history of MSK dysfunction during pregnancy
-higher BMI
-smoking
-work dissatisfaction (yellow flag)
-lack of belief of improvement of PGP (yellow flag)
what are risk factors post partum for PGP?
-prior episodes of PGP during pregnancy +/- LBP, stress urinary incontenence, pelvic floor dysfunction, C sesction
-pubic symphysis impairment - h/o delivery trauma, excessive unilateral leg loading postpartum (maybe due to pelvic asymmetry, muscle imbalance etc)
what are the 3 MAIN QUESTIONS you need to answer during the physical exam to determine PGP?
-is the SIJ or PS (pubic symphysis) the source of nociception (PS tender on palpation, loading pelvis = pain etc)
-are the SIJ moving normally? (small but important movement)
-is the pelvis symmetrical?
