SIJ Flashcards
what 2 m directly attach to the sacrum and directly produce SI motion
piriformis and pubo coccygeal m
what does the long dorsal SI ligament limit
anterior iliac rotation or sacral counter-nutation
what motions do the short SI ligament limit?
all motions
what is the function of the anterior sacroiliac ligaments
bind the sacrum and ilia
what are the most important ligaments of the SIJ and why?
interosseus sacroiliac ligaments
strong and thick, bind sacrum and ilia
what ligament is continuous with the tendon of the biceps femoris
sacrotuberous ligament
describe the attachments of the sacrotuberous ligaments
ischial tuberosity to ilia (PSIS)
lateral side of sacrum and coccyx
the sacrotuberous ligament blends with _______ ligament and together they resist _____
sacrospinous lig
nutation and posterior innominate rotation
what are the deep m that stabilize the SIJ
multifidi, TrA, pelvic floor and diaphragm
what is the function of the piriformis in NWB
- hip ER and ABD
what is the function of the piriformis during WB
restrains excessive hip IR
(deceleration of IR)
how does the function of the piriformis change with hip position
when hip flexed > 90, becomes a hip IR
what structures are part of the deep longitudinal system (sling)
ES
deep thoracolumbar fascia
sacrotuberous ligament
biceps femoris
what is the main function of the m sling systems
increase SIJ stability
what structures are involved in the posterior oblique system
Lats
C/L glut max
thoracolumbar fascia
what structures are involved in the anterior oblique system
EO
IO
C/L hip ADD
anterior abdominal fascia
what structures are involved in the lateral m systems
glut medius
minimus
C/L hip ADD
what are the inner muscles that stabilize the pelvis
miltifidi, TrA, pelvic floor
what is the iliac articular surface of the iliac covered with
fibrocartilage
what is the articular surface of the sacrum covered with
hyaline cartilage
what structure connects the pubic symphysis
fibrocartilage
what is a non-infectious inflammatory condition localized to the pubic area
osteitis pubis
what are some common causes of osteitis pubis
pregnancy, childbirth, high-level athletic activity, urological or gynecological surgery, trauma, psoriatic arthritis
the superior transverse axis travels through ______
the second sacral segment
describe the motion that occurs at the superior transverse axis during respiration
with inhalation - sacrum extends/counter-nutates
exhalation - sacrum flexes/nutates
the transverse pelvis axis travels through the _____
symphysis pubis
the middle transverse axis is located ____
at the 2nd sacral body
what is the principle axis of normal SI motion (nutation and counter nutation)
middle transverse axis
what is the principle axis of IS motion (anterior and posterior rotation)
Inferior Transverse Axis
the inferior transverse axis travel thru ___
inferior pole of SI articulation and PSIS
the R and L oblique axis runs thru ___
superior end of articular surface of sacrum to opposite inferior lateral angle
what is sacral motion
nutation and counternutation
nutation and counternutation occurs at what axis
middle transverse
what is the capsular pattern of sacral motion
pain with stress
describe the gliding motion of the sacrum during nutation
glides inferiorly down short limb and posteriorly along long limb
what is the CPP of the sacrum
nutation - occurs during WB
during nutation of the sacrum, what happens to the iliac bones and the ischial tuberosities
iliac bones move closer
ischial tuberosities move farther apart
nutation is resisted by what 3 ligaments
sacroiliac, sacrotuberous, and sacrospinous
describe the gliding motion of the sacrum during counter-nutation
glides anteriorly along the long limb and superior along the short limb
what is the OPP of the sacrum
counternutation
what 2 m produce counter-nutation
piriformis and pubococogeal
what happens to the iliac bones and the ischial tuberosities during counter nutation
iliac bones move farther apart
ischial tuberosities move closer
what ligaments resist counternutation
sacroiliac ligamnets
describe Forward torsion of the sacrum on the iliac bones
around the oblique axis
Ex: when the R base of sacrum points forward (rotating to the L) –> L torsion around the L oblique axis = L on L
also can look at L inferior angle –> when it is directed upwards –> L on L
describe backward torsion of the sacrum on the iliac bones
around the oblique axis
Ex: R base of sacrum moves backwards –> R torsion around the L oblique axis = R on L
what happens to the articular surface of the ilium during anterior rotation
glides inferior and posterior relative to sacrum
what happens to the articular surface of the ilium during posterior rotation
glides anterior superior in relation to sacrum
flexion at the hip will produce what innominate motion
posterior rotation (coupled with ER)
extension at the hip will produce what innominate motion?
anterior rotation (coupled with IR)
flexion of the lumbar spine will produce what sacral motion and what innominate motion
sacral - nutation THEN counternutation
innominate - anterior rotation
extension of the Lumbar spine will produce what sacral motion and what innominate motion
sacral - nutation
innominate - posterior rotation (slight)
during heel strike of R LE, what position is the R innominate in and what position is the L innominate in?
R (I/L side) - posterior rotation
L (C/L) - anterior rotation
during R heel strike - what axis is motion occuring at
R oblique axis - R on R or L on R
during R heel strike with the L foot still in contact with the ground - what m pulls the sacrum forward on the L side?
what motion is occurring?
L psoas pulls sacrum forward
R on R motion
During Mid-stance (L LE toe off and beginning to flex hip) what position is at the L iliac and what position is the R side
L - posterior rotation
R - Anterior roation
during midstance on the R LE (the R LE is the WB leg) - what axis is motion occurring at
R oblique
during R sided midstance, and the L innominate is posteriorly rotated, what torsion occurs ?
L on R torsion
at the moment of L heel strike, the axis _____
changes from R oblique axis to L oblique axis
what is the main cause of pelvic pain
sacroiliac arthritis
describe the referral pattern of the SIJ
TO the: lumbar spine, butt, hip, upper thigh
Hip and Lumbar spine can refer to the SIJ
do pts with SIJ pain have positive or negative neuro signs?
(-) SLR
what sign is used to determine SIJ pain
Fortin - can pinpoint pain in buttock region/over SIJ
S/S of sacroiliac arthritis
- pain in posterior sacrum
- radiating to post thigh
increased with walking (unilateral WB) or hopping - increased with turning in bed
- lumbar ext is most painful
+ stress test
+ compression test with belt
the following will cause what injury to the IS:
- repeated unilateral standing
- fall on ischial tub
- vertical thrust onto and extended leg
- back lifting
posterior innominate
the following will cause what injury to the IS:
- golf or baseball swing
- horizontal thrust to the knee (dashboard)
- forceful diagonal mvmt
anterior innominate
what do kinetic tests look for
hypomobility
what structures are responsible for force closure of the SIJ
TrA, sacral multifidi, pelvid floor and hip ER
what is responsible for form closure of the pelvis
- high friction coefficient compared to other joints
- wedge shape of sacrum
-ridges and grooves on articular surface - extensive ligement support
the active SLR is for?
funcitonal test for pelvis girdle stability
a positive ASLR is ____
decreased ability to actively lift leg in supine position from pain or difficulty
a positive ASLR is highly correlated with ______
excessive mobility of pelvic girdle
how do you augment form closure?
compression of SIJ - manual or SI belt
how can you augment force closure of the SIJ
use of slings
Pts with SIJ pain have a delayed activity of what m?
IO, MF, glut max
what is intra-articular SIJ injection used for?
short-term pain relief
what is prolotherapy and when is it effective?
- glucose compound injection used to stiffen SIJ
- effective ONLY when used in conjunction with other PT interventions
what has better evidence for longer lasting effects? Prolotherapy or SIJ steroid injection
prolotherapy
pelvic belt causes a significant decrease in ___
sagittal plane rotation of the SIJ
does the use of an SI belt have an effect on abdominal m thickness during ASLR?
no immediate effects on TrA or IO thickness
in comparison of 2 exsc for SIJ laxity (ADIM - TrA or general abdominal bracing exsc) which one is more effective?
BOTH decreased joint laxity BUT ADIM decreased laxity more
