Innominates _ES Flashcards
What is the role of the pelvis?
- body support
- locomotion
- maintains stability - distributes the effects of mass, gravity, and mechanical forces from above and below
- at base of vertebral column, yet still long way from the ground
The weight of the upper body is directed through the ___ and ____ downward and the resistance to forces from below forma balance at the pelvis
spine
axial skeleton
What creates a great potential for SD?
injury, postural and muscle imbalances directed from above or below towards the pelvis
What influences LE circulation and drainage?
pelvic diaphragm and inguinal area
What are the main functions of the pelvis?
- biomechanical function and balance: foundation for body support and locomotion
- reproduction (genital structures)
- elimination (GI and urologic)
- vascular and lymphatic functions for the region
What are the bones of the inominate?
ilium, pubis, and ischium
How many ossification centers are in the acetabulum?
3
What are major pelvic ligaments?
- anterior
- posterior
anterior
- sacropinous
- iliolumbar
- anterior sacroiliac l
- inguinal l
posterior
- sacrotuberous
- posterior sacroiliac l
What is the sacrospinous l?
sacrum to spine of ischium
What is iliolumbar l?
from ilia to 5th lumbar vertebra
- stabilization of L5 (possibly L4)
- stabilizes anterior motion of the lower lumbar spine
- restricts anterior and rotary motion of L5
- blends with the upper part of the anterior SI l
What is anterior sacroiliac l?
covers much of SI joint
- connects the 3rd sacral segment to the lateral side of the pre-auricular sulcus
- thicker than the posterior SI ligaments to prevent the sacrum from “popping” out anteriorly
What is inguinal l?
ASIS to superior pubic rami
- consists of thick bands which extend from the ASIS to the pubic tubercle
- forms the floor of the inguinal canal through which an indirect inguinal hernia may develop
- give origin to the internal oblique and transversus abdominis m
What is sacrotuberous l?
sacrum to ischial tuberosity
What is posterior sacroiliac l?
covers much of SI joint
- inferior fibers from the 3rd and 4th sacral segments, ascend to the PSIS and posterior end to the internal lip of the iliac crest
- blends with STL and thoracolumbar fascia
What is the interosseous sacroiliac l?
major bond between the bones, filling the irregular space posterosuperior to the joint
-covered posteriorly by the posterior sacroiliac l
What is the pubic symphysis?
- lies anteriorly btwn the adjacent surfaces of the pubic bones
- each of the joint’s surfaces is covered by hyaline cartilage and is linked across the midline to adjacent surfaces by fibrocartilage
- joint surrounded by interwoven layers of collagen fibers and the two major ligaments: superior pubic ligmaent and inferior pubic ligament
Describe the forces of the pubic symphysis
extremely strong posterior ligaments
articulation at SI joint
Describe the innominate biomechanics of the heel strike
- innominate rotation
- muscles
- right leg glides forward and this is aided by the right innominate rotating posteriorly
- contralateral innominate rotates anteriorly
- iliopsoas and quadriceps femoris were contracted to flex the LE at the hip
- iliopsoas contraction and motion of the swing phase act upon the innominate to cause posterior rotation
Describe innominate biomechanics of toe off
- rotation
- muscles
- body does a controlled fall forward with the left leg gliding forwards and anterior rotation of the innominate is mainly a passive process
- contralateral innominate rotates posteriorly, mainly an active process
- iliopsoas relaxation allows anterior rotation of the innominate with gluteus maximus and hamstring contraction to extend the LE at the hip
- ipsilateral e spinae and quadratus lumborum contraction aids anterior innominate rotation
5 major hip/pelvis muscle groups
- flexors - 2 at hip, 2 act at hip and knee
- external rotators -6
- adductors - 3 plus 2 minor
- abductors -3
- extensors - 4
hip flexors
major
- iliacus
- psoas
minor
- rectus femoris
- sartorius
iliacus
hip flexor major
from ala of ilia (iliac fossa) to lesser trochanter fo the femur
psoas (major and minor)
major hip flexor
from the 5 lumbar vertebrae to the lesser trochanter of the femur
rectus femoris
minor hip flexor
AIIS to patella
sartorius
minor hip flexor
ASIS to medial tibia
Dysfunction of what muscles may cause an anterior rotation of the innominate and/or inferior shear at the pubes?
rectus femoris, iliacus, or the ipsilateral adductor group
Hip extensors
- gluteus maximus
- hamstrings: biceps femoris, semitendonosis, semimembranosis
gluteus maximus
hip extensor
posterior iliac fossa to posterosuperior aspect of greater trochanter and femur
semimembranosis
hip extensor - hamstring
ischial tuberosity to medial tibia
semitendinosis
hip extensor - hamstring
ischial tuberosity to medial tibia
biceps femoris
hip extensor -hamstring
ischial tuberosity and STL to lateral fibula and tibial plateau
hamstring tension may cause a ____ rotation of the innominate and affect pelvic mechanics
posterior
hip adductors
major
- ad magnus
- ad brevis
- ad longus
minor
- gracilis
- pectineus
major adductors
- what muscles
- O
- I
brevis, magnus, and longus (superior to inferior)
O: body and inferior ramus of pubis
I (brevis and magnus): pectineal line and proximal part of linea aspera of the femur
I (longus): superomedial surface of the distal femur
pectineus
minor hip adductor
O: pectineal line on the pubic bone
I: pectineal line on the femur
gracilis
minor hip adductor
O: inferior ramus of the pubis
I: the medial aspect of the proximal femur and tibial plateau
hip abductors
gluteus medius
gluteus minimus
tensor fascia lata
gluteus medius
hip abductor
posterior ischial fossa to superior greater trochanter
gluteus minimus
hip abductor
posterior ischial fossa to superior greater trochanter
tensor fascia lata
- muscle group
- O/I
hip abductor
O: from anterior part of external lip of the iliac crest, the lateral surface of the ASIS and the notch inferior to the ASIS
I: upon the iliotibial band, which eventually inserts into the lateral condyle of the tibia
trendelenburg sign
- used to determine whether the pt has adequate hip abductor strength, particularly of the gluetus medius.
- pt instructed to stand on both feet and slowly raise one foot off the ground without additional support
- if the pt has adequate abductor strength then the both hips should remain level or slightly elevated to the standing side
- should maintain an upright posture w/o lateral tilt
-drop of pelvis when lifting leg opposite to weak gluteus medius
hip external rotators
piriformis
obturator - externus and internus
gemelli - superior and inferior
quadratus femoris
piriformis
- muscle group
- I/O
- abnormal contraction
- hip external rotator when hip is extended and abductor when hip is flexed
- from anterior sacrum to sup greater trochanter
- abnormal contraction may cause sciatica (sciatic N pierces piriformis in 10-12% of population)
- *the only hip rotator that connects directly to the sacrum**
gemelli superior and inferior
hip external rotator
from ischial spine to greater trochanter
obturator internus and externus
hip external rotator
from obturator membrane to the greater trochanter
quadratus femoris
hip external rotator
from ischial tuberosity to greater trochanter
secondary muscle attachments
- rectus abdominis
- transversus abdominis
- internal and external oblique
- quadratus lumborum
dysfunction of the quadratus lumborum may produce symptoms similar to a groin pull or hernia by irritating the _____ and ____ nerves as they pass just anterior to this muscle
ilioinguinal and iliohypogastric L1
What separates the greater sciatic foramen and lesser sciatic foramen?
sacrospinous ligament
What can be seen in the gravitational line?
- auditory meatus
- acromion process
- greater trochanter
- body of L3
- anterior 1/3 of sacrum
- lateral condyle of knees
- lateral malleolus
What are some problems of the pelvis?
- anterior/posterior innominate rotation
- superior/inferior innominate shear
- out-flare or in-flare
- pubic bone shear
- pubic bone abduction/distraction
- pubic bone adduction/compression
What palpatory landmarks are used for innominate SD?
- iliac crests
- ASIS
- pubic tubercles
- medial malleoli heights (least reliable)
- PSIS
- ischial tuberosities - only used in diagnosis for small hemipelvis (one side of pelvis is congentially smaller than the other)
What is the order of finding SD diagnosis?
lateralization
- standing flexion
- ASIS compression
palpation of landmarks
- iliac crest
- ASIS
- pubic tubercles
- PSIS
- medial malleoli
- possible ischial tuberosity
What is the standing flexion test?
- pt standing, physician behind pt with eyes at level of patient’s PSIS
- contact the inferior aspect of the PSIS bilaterally
- ask pt to bend forward with hands towards toes, knees straight
- let thumbs follow the motion of the PSIS
+ test = one PSIS moves farther superiorly
indicates SI joint dysfunction on the side that elevates first
What is the ASIS compression test?
- pt supine
- physician stands with dominant eye closest to the patient’s body
- contact the ASIS bilaterally, induce a force through aSIS toward the table (posterior and medially) alternating between right and left hands
+ test = “hard end-feel” or “restriction of motion” on one side
indicates SI joint dysfunction on the side of restricted motion
