PELVIS Flashcards
What does the functional uint of the pelvic girdle consist of
- 2 Innominates
- The sacrum
- Bilateral hip joints
- L4/L5
What is the definition for form closure
A stable situation with closely fitting joint surfaces, where no extra forces are needed to maintain the state of the system
What structures does the passive system of form closure of the SI joint include
Joint congruency: Interlocking grooves and ridges + wedge shape of sacrum
Ligamentous support: Interosseous ligament, ventral and dorsal SI ligaments, sacrotuberous ligament, sacrospinous ligament, long dorsal ligament
What disrupts the form closure of the SI joint
Disruption in bony integrity
Pregnancy
When is force closure of the pelvis needed
during loading
Are muscles that are perpendicular or parallel to the joint surface more important for force closure
perpendicular
Which muscles are particularly important for force closure of the pelvis
Glute max
TA
What is the self-locking mechanism of the pelvis
The combination of form and force closure used for optimal pelvic function
What is the axis of motion of the SI joint
unknown
- Proposed that there may be many axes
What are the arthrokinematics of the SI joint
unknown
Small amounts of cranial/caudal, ventral/dorsal gliding occurs
What is the total ROM of the pelvis
up to 4 degrees
Why is movement of the pelvis essential
For shock absorption and to absorb torque force in locomotion
What are the available movements of the innominate
Anterior and posterior rotation
What are the motions of the sacrum
Nutation and counternutation
What is nutation of the sacrum? What occurs to the sacral sulcus in nutation? Is nutation stable or unstable?
flexion of sacrum in pelvic bowl
Sacral sulcus deepens
Stable for SI joint
What occurs to the Sacrotuberous and sacrospinous ligaments in nutation
they tension
What is counternutation of the sacrum? What occurs to the sacral sulcus in nutation? Is nutation stable or unstable?
Extension of the sacrum
Sulcus shallow
Unstable for the SI joints
What is the cause of pelvic girdle pain
loss of form or force closure
What are some differential diagnosis for Pelvic girdle pain syndrome
- Inflammatory conditions (AKS)
- Systemic diseases (Reiters syndrome)
- Pelvic inflammatory disease
- Visceral dysfunction (UTI)
- Lumbar spine and hip dysfunction
What is the onset for Pelvic girdle pain syndrome
- Traumatic: fall, sports, MVA
- Insidious: Repetitive strain, pregnancy, peri-partum, muscle imbalance, post abdominal, surgery, biomechanical adaptation, cyclical
What is the location for Pelvic girdle pain syndrome
- Local/unilateral
- Referral to buttock, groin, posterior thigh, anteromedial thigh
- Tenderness - particularly over the posterior SI joint line
What are the aggravated and easing factors seen with Pelvic girdle pain syndrome
Aggravating: rolling over in bed, single leg stance, stepping out of car
Easing: Rest, side lying pillow between knees