Innominate Mechanisms and Diagnosis Flashcards
Sacroiliac Dysfunction Presentation
- Highly variable
- Groin pain, hip pain
- Pain below iliac crest
- Medial buttock pain
- Lateral sacral pain
- Referred pain can be to groin, butt, or posterior thigh
- Usually unilateral
- There is often assoc. hamstring tightness
Joints of the pelvis
- 2 sacroiliac joints
- Symphysis pubis
What kind of joint are sacroiliac joints
- Diarthrodial (synovial) joint
Physiologic motion of Innominate
- Rotation
3 true sacroiliac ligaments
- Anterior SI ligaments
- Interosseous SI ligaments
- Posterior SI ligaments
3 accessory pelvic ligaments
- Sacrotuberous
- Sacrospinous
- Iliolumbar
Sacrotuberous ligament anatomy
- Attaches from inferior medial border of sacrum to ischial tuberosity and posterior sciatic notch
- Blends w/ other sacral ligaments
Sacrospinous ligament anatomy
- Attach to ischial spines
- Divide the space into greater and lessor sciatic foramen
Iliolumbar ligament anatomy
- Attaches from anterior iliac crest to transverse processes of L4, L5
- Lower fibers attach to anterior sacral base, blending w/ ant SI lig
- Prone to irritation by lumbosacral instability
- Iliac crest and transverse processes of L4-5 can be tender, especially the area b/w the two
- Referred pain to groin via ilioinguinal nerve
- Need to assess ligaments as well as bony structures
Levator ani group
Make up pelvic diaphragm
- Pubococcygeus
- Puborectalis
- Iliococcygeus
Primary intrinsic pelvic muscles
- Levator ani group
Secondary pelvic muscles
- Rectus abdominis
- Internal and external oblique
- Transverse abdominis
- Quadratus lumborum
Pelvis lower extremity muscles (Anterior and medial compartments)
Anterior and medial compartments
- Iliacus
- Sartorius
- Rectus femoris
- Gracilis
- Adductor group
Pelvis lower extremity muscles (Lateral compartment)
- Tensor fascia lata-ITB
Pelvis lower extremity muscles (Posterior compartment)
- Glutei maximus, medius and minimus
- Obturator externus and internus
- Superior and inferior gemeli
- Biceps femoris
- Semimembranosus
- Semitendinosus
Muscles with fasical coverings continuous w/ the posterior SI ligament?
- Piriformis
- Biceps femoris Inflammation of the SIJ could affect piriformis and biceps femoris through reactive muscle spasm
What muscle ligament blends w/ posterior iliosacral ligaments over the lower half of the SIJ?
- Gluteus maximus
Innominante motion
- Can be functionally considered as part of the lower extremities
- Rotate anteriorly and posteriorly about the inferior transverse axis of the sacrum = inferior limb SIJ at level of S3
- Induced by hip motion such as during gait - Or by muscular forces from above or below
Motion of Pubes
- Cartilagenous joint w/ fibrous disc
- Allows for twisting/ rotational mvmt of the innominate about a transverse axis
- Ipsilateral rotation inferiorly w/ anterior rotation of ilium
- Can be sheared superiorly or inferiorly
- Can be sheared anteriorly or posteriorly; rare
- Can be gapped or compressed; rare
Motion of Walking Cycle: Right Heel Strike
- Quads activate and start anterior right innominate rotation
- Weight bearing increases anterior rotation about the inferior transverse sacral axis (S3)
- Sacrum rotates about alternate oblique axes
- Shear forces are taking place at pubes
Motion of Walking Cycle: Right Toe-off
- Hamstrings activate and start posterior right innominate rotation
- Shift in weight bearing facilitates posterior rotation about the inferior transverse sacral axis (S3)
- Sacrum rotates about alternate oblique axes
- Shear forces are taking place at pubes
Physiologic Innominate Dysfunction
- Muscles, connective tissue, and joints remain in positions that are normally a part of physiologic motion
- These dysfunctional because they have not returned to neutral
- These consist of anterior or posterior rotations
Non-Physiologic Innominate Dysfunction
- Often induced by trauma
- Findings are not consitent w/ physiologic motion
- These include innominate and pubis shears
*may occur together or independently
Diagnosis of Innominate Dysfunction
- Motion restriction and asymmetry of the sacroiliac joint and pubic symphysis
*this can manifest at SI joint
*innominates anteriorly
*Pubic symphysis
*internal/ external rotation asymmetry of the lower extremities
- Tissue texture change and tenderness are also clues
*iliolumbar ligament
*sacral sulcus
*anterior lumbar tenderpoints (AL1-5)
*other anterior tenderpoints
Lateralization test checks for
- Motion of the SIJ
PSIS position vs. Ipsilateral ASIS during pevlic exam
- PSIS postion will be opposite of the ASIS on the same side
Standing vs. Seated Flexion Test
- Standing flexion test tells if theres anything wrong w/ the SIJ and which side
- Seated tells you whether its a sacral or innominate problem
*pos. test = sacral problem
*neg. test = iliac (innominate) problem
Sacroilieac vs. Iliosacral problem
- Sacroilieac = problem w/ sacrum
- Iliosacral = problem w/ ileum
Posterior Innominate Dysfunction Anatomical Signs
- Entire innominate appears rotated posterior relative to other side of hip
- Standing forward flexion test is pos. on that side
*PSIS rises on the side of SIJ restriction
- Supine
*ASIS is superior (and posterior)
*Apparent short lower extremity
- Prone
*PSIS inferior
- Standing
*PSIS is inferior
Posterior Innominate Dysfunction Symptoms
- Tight Sacrotuberous ligament on same side
- Inguinal groin pain/ tenderness due to rectus femoris dysfunction
- Medial knee pain due to sartorious dysfunction
Anterior Innominate Rotation Signs
- Entire innominate appears rotated anterior relative to other side of hip
- Standing forward flexion test is pos. on that side
- Supine
*ASIS is anterior and inferior
*Pos. ASIS compression test ipsilaterally
*Apparently long lower extremity
- Prone
*PSIS superior
*SIJ restricted
- Standing
*PSIS is superior
Anterior Innominate Rotation Symptoms
- Iliolumbar ligament tenderness same side
- Tissue texture changes at the ipsilateral ILA (inferior lateral angle) of the sacrum
Superior Innominate Shear Signs
Dysfunctional side has
- Superior ASIS
- Superior PSIS
- Superior pubic ramus?
- Pos. ASIS compression test
- Pos. standing flexion test
- Often there are tissue texture changes at ipsilateral SIJ and/or isilateral pubes
- More common than inferior shears
Inferior Innominate Shear Signs
Dysfunctional side has
- Inferior ASIS
- Inerior PSIS
- Inferior pubic ramus
- Pos. ASIS compression test
- Pos. standing flexion test
- Often there are tissue texture changes at ipsilateral SIJ and/or ipsilateral pubes
Shear Dysfunctions
- Non-physiological
- Occur in directions not normally assoc. w/ sacroiliac motion
- Should be treated before physiologic dysfunctions
Innominate Flare Dysfunctions
- Involves a positional change w/ the ASIS becoming more medial or lateral to its usual position
- Visualize rotation of the innominate about a vertical axis
Innominate Outflare Dysfunction Sign
- ASIS more lateral on dysfunctional side
*muscles lax on side of outflare
*SIJ compressed
Innominate Inflare Dysfunction Signs
- ASIS more medial on dysfunctional side
- Muscles are taut on side of inflare (medial flare)
- SIJ is relatively separated
Vertical Pubic Shears
- Isolated vertical pubic shears may or may not actually exist
- Ther emay be a component of rotation or subluxation that is difficult to diagnose
- Sometimes the ASISs and PSISs appear displaced w/ one superior and the other inferior
- Named for side of dysfunction
- Often superior pubic shear is assoc. w/ a posterior or superior (up-slipped) ilium and opposite w/ inferior pubic shear
Pubic Shears
- Anterior pubic shears are uncommon and usually assoc. w/ trauma
- One side of the symphysis is anterior to the other
Pubic Symphysis Dysfunction Signs
- Check for L5 counterstrain tenderpoint
- Compression dysfunction = bulge
- Seperation dysfunction = divet or gapping
