The Pelvic & Hip Region Flashcards
What are some functions of the pelvis?
- contain and support visceral contents
- transmit and absorb forces (upwards and downwards)
What is the innominate?
either of the two bones forming the sides of the pelvis, each consisting of three consolidated bones, the ilium, ischium, and pubis.
What bones make up the pelvic girdle?
bones of the innominate (ilium, ischium, pubis) and the sacrum
How are the innominate bones attached at birth vs adulthood?
separated by hyaline cartilage at birth - by 25 years of age they are fully grown and fused
The sacrum is a large inverted triangle. Which half is non weight bearing?
the inferior half is non weight bearing
Sacrum differences in male vs female?
wider and flatter in females
The sacrum consists of # fused vertebrae and it articulates with what?
5
Articulates with the lumbar and coccygeal vertebrae
The sacroiliac joint is a ____ joint.
synovial
Does the SI joint have hyaline cartilage?
Yes - on both articular surfaces of the sacrum and ilium
What happens to the SI with age?
becomes stiffer and irregular
What is the movement of the SI joint? When can it be greater?
Small motion - 2-4mm approx.
Can be greater during 1st and 3rd trimester of pregnancy, as well as in blondes with fair skin
With age, what contributes to form closure of the SI?
reciprocal undulating hyaline articular surfaces on sacrum and ilium as well as ligaments
What are the three components of functional stability at the SI joint?
Passive system: osseous, capsule, ligaments
Active System: muscles
Neural System: sensory receptors, nerves, spinal cord and supra-spinal centers, reflexes and/in active system
Form vs Force closure for structural integrity?
Form: passive structures - interlocking articular ridges and grooves of the SI joint, reverse keystone configuration of the sacrum within the pelvic ring and fibrous ligaments suspend pelvis
Force: muscle activation - external dynamic forces created by contraction of the stabilizing muscles to produce a “self-locking” mechanism, resulting in increased joint stability
When does the keystone theory not work?
when looking from a superior view (as opposed to anterior-posterior)
How is the sacrum held to the ilium from a superior viewpoint?
by ligamentous support and force closure
“concept posits that the sacrum is the reverse of a keystone”
tensegrity - the sacrum is a hub!
Movements of the sacrum:
- ____ is sacral anterior rotation (flexion)
- ___ is sacral posterior rotation (extension)
nutation
counternutation
Standing on both legs performing flexion at the trunk we will have _____ of the sacrum and ____ rotation of the inominate
nutation
anterior
Standing on left leg while flexing right hip joint the right innominate will ____ rotate and the left inominate will not move, the sacrum will ____ on the right side more than left (indicating movement at SI joint)
posteriorly
counternutate
When standing and walking, the weight of the body is where?
through the sacrum to the SI joint to the pubic symphysis and the heads of the femurs
When sitting, where is the weight?
through the SI joint to the pubic symphysis and ischial tuberosities
the ____ ligaments are between the lateral sacral crest and the inner side of the iliac tuberosity
interosseous
Differences between anterior and posterior sacroiliac ligaments?
anterior SI ligaments are thinner and not as extensive as posterior ligaments
the anterior and posterior SI and interosseous ligaments act to do what?
suspend the sacrum from the ilia
What type of joint is the pubic symphysis?
amphiarthrotic cartilaginous symphysis joint
what is the pubic symphysis joint separated by? Does this joint have hyaline cartilage?
fibroartilaginous disc
yes, on both pubic bone articulating surfaces
the ___ ___ completes the closure of the pelvic ring
symphysis pubis
Explain the mechanical advantage of the femur having a long neck?
Mechanical advantage for glut muscles and lateral rotators (force x distance = more torque)
All abductor muscles insert onto what aspect of the femur?
Linea aspera - hamstring muscles also come off of here
what is the angle of inclination of the femur?
125 degrees with the anatomic axis of the shaft of the femur
anatomic vs mechanical axis of the femur?
anatomic = line through the femoral shaft
mechanical = line connecting the centers of the hip and knee joints, which is typically a vertical line in the standing position
____: distal end of the femur is more lateral relative to the midline
valgus
____: distal end of the femur is more medial relative to the midline
varum
Angle of inclination pathologies: coxa valga?
- excessive angle
- leg appears longer
- weaker abductors
Angle of inclination pathologies: coxa vara?
- reduced angle
- predispose to fracture
- common later in life
Head of the femur points what way?
it is anteverted - points anteriorly by 12-15 degrees
Angle of torsion the femur is in what plane?
transverse
What is anteversion?
excessive torsion - 25 degree angle = toeing in
What is retroversion?
decreased torsion - 8 degree angle = toeing out
Joint classification for the hip? DOF?
ball and socket, synovial membrane - 3 DOF
Movements at the hip joint?
flexion/extension
abduction/adduction
int./ext. rotation
Osteokinematics of the hip?
swing and spin
Where is the hyaline cartilage of the hip?
superior, superior anterior, and superior posterior - there is none inferiorly or in the center
What is in the center of the acetabulum?
the acetabular fossa that contains mobile fat pad and no articular cartilage
What is the ligament attached to the head of the femur?
ligamentum capitis femoris/ ligamentum teres
What is the function of the ligamentum capitis femoris?
to carry the vascular supply to the head of the femur
When is there tension on the ligamentum teres?
in extreme positions of adduction, flexion, and external rotation or adduction, extension, and internal rotation
the ____ ____ is space for the ligamentum teres
acetabular fossa
the acetabular fossa is a reservoir for synovial fluid, how does this help the hip?
when it is heavily loaded to fluid comes here, and when forces are decreased the fluid returns to articular surfaces to provide lubrication and nutrition
Where is the labrum and what is itmade of?
- rims the acetabulum, increases the enclosure on the head of the femur
- fibrocartilaginous
the ____ is a strong structure that attaches the outer rim of the acetabulum to the neck of the femur
capsule
how is strong stability provided at the joint?
negative atmospheric pressure in the capsule
Arthrokinematics - Convex on concave - during flexion, how does the head move?
glides posteriorly
Arthrokinematics - Convex on concave - during abduction, how does the head move?
glides inferiorly
Arthrokinematics - Convex on concave - during external rotation, how does the head move?
glides anteriorly
The hip joint is supported by three strong ligaments that are embedded within the capsule. What are they? What do they contribute to?
- Iliofemoral
- Ischiofemoral
- Pubofemoral
Contribute to ability to stand upright with minimal muscular effort
How does the iliofemoral ligament cover the hip? What movements does it prevent?
- covers anteriorly and superiorly
- prevents excessive hip extension and external rotation
the ____ ligament helps screw the femoral head into the acetabulum
iliofemoral ligament
When you move into extension and external rotation, what ligament is getting tightened?
iliofemoral ligament
How does the ischiofemoral ligament cover the hip? What does it help prevent?
- covers posterior and inferior hip
- prevents hip hyperextension, abduction and internal rotation
The _____ ligament is tight with extension, abduction, and internal rotation.
ischiofemoral ligament
what hip ligament is the weakest of the big three?
ischiofemoral
the pubofemoral ligament covers what part of the hip? what does it prevent?
- covers anterior and inferior hip
- prevents over-abduction, and limits extension and external rotation
the _____ ligament gets tensioned with extension, abduction and external rotation
pubofemoral
Degrees and EF: hip flexion with knee extended?
70-90 degrees
firm
Degrees and EF: hip flexion with knee flexed?
____ degrees
soft
Degrees and EF: hip extension
0-30 degrees
firm
Degrees and EF: hip abduction
45 degrees (this seems to vary a lot with age; 53 degrees at 4 yrs --> 21 degrees at age 87) firm
Degrees and EF: hip adduction
30-40 minutes
firm
Degrees and EF: hip internal rotation
40 degrees
firm
Degrees and EF: hip external rotation
45 degrees
firm
nerve supply to the leg: lumbar plexus T__ - L__
T12-L4
What muscles does the obturator nerve supply?
Lumbar plexus L2-4
The adductors - adductor magnus, brevis, longus and gracilis - as well as obturator externus
What muscles does the femoral nerve supply?
Lumbar plexus L2-4
Quads (RF, VI, VL, VM), sartorius, and pectineus (only adductor not done by obturator
What muscles does the superior gluteal nerve supply? (sacral plexus)
gluteus minimus and medius and the TFL
What muscles does the inferior gluteal nerve supply? (sacral plexus)
gluteus maximus
What muscles does the sciatic nerve supply? (sacral plexus)
branches to semimembranosis, semitendonosis, biceps fem, adductor magnus
What muscles does the tibial nerve supply? (sacral plexus)
gastrocs (med/lat), soleus, plantaris, tib posterior and flexors of foot
What muscles does the common peroneal nerve supply? (sacral plexus)
peronei (longus and brevis)
What muscles does the deep peroneal nerve supply? (sacral plexus)
tibialis anterior, extensor digitorum, extensor hallucis
what muscles insert into the IT band and create tension and stability at the knee when they contract?
glut max and TFL
Glute Max: the upper fibers in conjunction with ____ can help with what action?
TFL
abduct
Glute Max: the lower fibers help with what action?
they are below the joint line so they can help to adduct
Action of the glut max?
- extension
- laterally rotate thigh at hip
- upper fibers abduct
- lower fibers adduct
Nerve innervation for glute max?
inferior gluteal nerve
action for the glut med?
- abduct
- internally rotate
- posterior fibers extend and laterally rotate
- anterior fibers flex
- horizontal abduction when in flexion
does the glute med have more anterior or posterior fibers?
there are very few posterior fibers relative to anterior fibers
nerve supply for the glute med?
superior gluteal nerve
actions for the glute min and nerve supply?
-abduct
-internally rotate
(same as glute med)
-nerve = superior gluteal
what nerve innervates the biceps femoris long and short head?
sciatic nerve (tibial and common peroneal nerve)
what are the say grace before tea muscles?
sartorius
gracilis
semitendinosus
what nerve innervates the semimembranosus and semitendinosus?
sciatic (tibial) nerve
What do all of these muscles have in common: piriformis superior gemellus obturator internus inferior gemellus quadratus femoris obturator externus
they are all lateral rotators because they are posterior to the hip joint!
If you are in pigeon pose, what muscle are you stretching?
piriformis! because you are in a supra-flexed position and laterally rotated
The piriformis does lateral rotation and extension of the thigh at the hip , but when you hit ___ degrees of flexion it medially rotates and horizontally extends (abducts) the thigh at the hip
60
What is piriformis syndrome?
pressure on sciatic nerve - this happens cause the sciatic nerve comes from right under the piriformis
what nerve supplies the piriformis?
the nerve to piriformis from lumbosacral plexus
What nerve supplies the superior gemellus?
nerve to obturator internus from lumbosacral plexus
what nerve supplies the inferior gemellus?
nerve to quadratus femoris from lumboscaral plexus
When doing the “open-the-gate” warmup in soccer, what muscle are you warming up?
the obturator internus
also the piriformis and superior/inferior gemellus
what nerve supplies the obturator internus?
nerve to obturator internus from lumbosacral plexus
what nerve supplies the obturator externus?
obturator nerve
what nerve supplies the quadratus femoris?
nerve to quadratus femoris from lumbosacral plexus
Why is the tensor fascia latae considered the charleston muscle?
because it does flexion, medial rotation and abduction - just like the dance move from the 1920’s!
what nerve supplies the TFL?
superior gluteal nerve
what muscle is the primary flexor of the hip?
iliopsoas
what two muscles make up the iliopsoas?
psoas major and iliacus - they both have the same insertion (lesser tubercle of femur) so they are considered one muscle generally
what muscle would be really tight on someone that has a large anterior pelvic tilt?
iliacus
what nerve supplies psoas major?
branches from lumbar plexus
what nerve supplies the iliacus?
femoral nerve
what nerve supplies rec fem?
femoral nerve
what nerve supplies the vastus group?
femoral nerve
how does the sartorius act as a knee flexor?
when it wraps around to the front of the tibia it comes posterior to the knee joint and is held in that position, so it helps with flexion
which muscle is the criss-cross muscle?
sartorius - it does flexion, abduction, and lateral rotation of thigh at hip and flexion of leg at knee
what nerve supplies the sartorius?
femoral nerve
what muscles are in the medial compartment?
this is aka the adductor compartment - consists of adductor magnus, longus, brevis, pectineus, and gracilis
What nerve supplies all the adductor muscles? What muscle is the exception?
Obturator nerve - supplies all except pectineus which is femoral nerve because it originates so high up compared to the others
where do the “say grace before tea” muscles all insert?
antero-medial aspect of the tibia
Pelvic inclination - a forward tilt involves what muscles? Does it increase or decrease lumbar lordosis?
- iliopsoas, rec fem, and erector spinae
- increases lordosis
Pelvic inclination - a backward tilt involves what muscles? Does it increase or decrease lumbar lordosis?
- rectus abdominus, most hamstrings, and gluteus maximus
- decreases lordosis
If someone has excessive anterior pelvic tilt, what needs to be stretched and strengthened?
Stretched: psoas major, iliacus, rectus femoris
Strengthened: hamstrings, gluteus maximus and abdominals
If someone has excessive posterior pelvic tilt, what needs to be stretched and strengthened?
Stretch: hamstrings, gluteus maximus, and abdominals
Strengthen: psoas major, iliacus, rectus remoris
Muscle function can change depending on joint position. How does the action of the following muscles change depending on joint position:
- Piriformis
- Abductors
- Glut Med and TFL
- Piriformis does external rotation, but when it is in a super-flexed position it switches to internal rotation
- Abductors switch to horizontal extension when flexed at hip
- Glut Med and TFL are internal rotators of the hip, but their leverage for internal rotation increases further when the hip is flexed to 90 degrees
How does the adductor longus perform agonist and antagonistic actions at the hip?
It flexes when leg is in an extended position and it extends when the leg is in a flexed position
The piriformis, gemelli, ad obturator internus have a good angle of pull for external rotation, but as the hip flexes to 90 degrees, what do they shift to?
horizontal extension (abduction)
The anterior portions of the gluteus medius and minimus and TFL increase their leverage for ____ ____ when the hip is flexed (to approx. 90 degrees)
internal rotation
the posterior portions of glut med and min can laterally rotate particularly when leg is in _______
extension
How do you keep sarcomeres at an ideal mid-length range over a two joint muscle?
you need to stretch over one and flex over another
What position should the leg be in if the rec fem wants to produce the most force as a hip flexor?
the knee should be flexed
think of kicking a soccer ball
What position makes the rec fem amore efficient knee extensor?
if the hip is extended
The hamstrings are more efficient as hip extensors when the knee ____ and are more efficient as knee flexors when the hip is _____
extends; flexed
Playground example: When you are hanging upside down on the monkey bars by your knees, what muscles are involved and what joint positions can be used to enhance the effectiveness of the muscles needed to keep you hanging there?
-dorsiflex so that gastrocnemius are lengthened and
can have more force production
- also has slight hip flexion - this helps hamstrings
What muscles are active when doing a crunch?
neck flexors and abdominal muscels perform concentric actions until the trunk is flexed
What muscles are active during a full sit-up?
neck flexors and abdominal muscles concentrically until the trunk is flexed, and then the iliopsoas become the prime mover to raise trunk and pelvis on the fixed femur
what happens when you fix feet during a situp?
the hip flexors contribute more! you dont even need to use your abs
What happens in a sit-up if your abs aren’t strong enough to maintain lumbar flexion?
the great force of the psoas major pulls the lumbar spine into hyperextension (lordosis) and anteriorly tilts the pelvis - this repetitive performance can lead to microtrauma and injury
how do you differentiate tightness in iliopsoas vs rec fem vs TFL?
do the Thomas test! If the hip stays flexed its iliopsoas, if knee extends its rec fem, and if leg abducts then its tight TFL
Four important muscles serve as Hip Extensors in all positions of the hip joint; what are they?
- Glute Max
- Biceps Femoris (long head)
- Semimembranosus
- Semitendinosus
Remember the adductors can also act as extensors when the hip is in what position?
flexion
During low power hip extension (ie. walking and long distance running, stair ascending and descending, rising from sitting), what hip extensors are primarily active?
hamstrings
When hip extension motions become more rapid or are accompanied by moderate-max resistance, what muscles assist the hamstrings?
glute max also becomes activated - POWER = glute max
What muscles will be quite large on a sprinter?
glute max
Outside of power, what also influences the contributions of hamstrings vs glute max during hip extension?
hip joint position relative to knee joint posotion
What is the benefit of having the greater trochanter away from the hip joint?
allows for greater force production by abductors - this is a mechanical advantage because the fulcrum is longer so more torque = more force
When standing on one leg, what is helping bring your pelvis up so it doesn’t drop when you pick up your foot?
reverse origin insertion of the hip abductors
If someone is walking and you see a right side pelvis drop during stance phase on left foot, what does this mean? What else might you observe in the movement
- weak left hip abductors
- might also see a lean of the trunk to the weak side to counterbalance
What type of lever system is the hip abductors around the femoral head during stance phase?
first class lever: muscle pulls down, GRF pulls up, body weight pulls down (look at pic if needed - slide 93)
Hip abductors are at a mechanical disadvantage relative to body weight and must produce a force greater than __% body weight to maintain equilibrium
85%
In someone with Trendelenburg Gait, what side should the cane be on?
the contralateral side so that you can de-weight the standing leg (side that dips) and then you can keep the pelvis level
When retraining hip abductors in a Trendelenburg Gait, what must you be cautious about?
that the client doesn’t compensate with quadratus lumborum and psoas major
Where do femoral fractures usually occur?
at the neck of the femur
Why are hip fractures more common in women?
due to increased osteoporosis in women after menopause
What does it mean if you break a bone from standing height?
you are clinically diagnosed with osteoporosis
what is a common site for osteoporosis?
calcaneus bone? apparently
Femoral fractures - fractures of the neck are most common, what is the next most common?
intertrochanteric fractures
In osteoarthritis we see a narrowing of joint space due to loss of cartilage. What else is seen?
Subchondral cysts and chondral bone spurs
How would you differentially stretch the rec fem vs iliopsoas?
For rec fem you will extend hip and flex at the knee
For iliopsoas you would extend at the hip, posterior pelvic tilt and bend trunk to contralateral side
