hip exam 3
center edge angle
- AKA the angle of wiberg - the extent to which the acetabulum covers the femoral head in the frontal plane -provides a protective shelf over the femoral head 35-40 degrees
secondary IR muscles
- anterior fibers of glut min and med - TFL -add longus - add brevis - pectineus - medial hamstrings
pubofemoral ligament
- attaches along anterior and inferior rim of acetabulum, superior pubic ramus and obturator membrane - blends with the fibers of the medial iliofemoral
iliofemoral ligament (Y ligament)
- attachment ASIS and adjacent margin of acetabulum to intertrochanteric line of the femur - one of the thickest and strongest ligaments of the body - standing with hip fully extended, anterior surface of femoral head rests against the ligament - passive tension in ligament is important stabilizing force
acetabular labrum
- blends with transverse acetabular ligament - deepens the concavity of the socket - adds stability
pelvic on femoral rotation in the sagittal plane: hip flexion
- can occur through a limited arc via and anterior tilt of the pelvis over a stationary femoral head
excessive anteversion may be associated with
- congenital dislocation - marked joint incongruence - increased wear articular cartilage - abnormal gait pattern (in-toeing)
internal rotation of support hip
- iliac crest on side of non support hip rotates forward in horizontal plane - pelvis rotating beneath a relatively fixed trunk
pelvic on femoral rotation in the horizontal plane
- internal rotation of support hip -external rotation of support hip
rotation of femur in horizontal plane
- larger subject inter-variability
acetabular fossa
- most centered part - should not contact the femur -depression deep in acetabular floor - devoid of cartilage - contains fat, synovial membrane, blood vessels
trendelenburg sign
- patient asked to stand in single limb support over weak hip -positive if pelvis drops to the side of the unsupported hip -positive indicates weak hip abductors -position of pelvic on femoral adduction - compensate by leaning the trunk to the side of the weakness
ischiofemoral ligament
- posterior and inferior acetabulum - superficial fibers spiral superiorly and laterally across posterior neck of femur to greater trochanter
abduction of support hip
- raising or hiking the iliac crest on the side of the non-supporting hip -L spine must bend in the direction opposite the rotating pelvis - lateral convexity toward side of abducted hip
ligamentum teres
-"ligament to head of the femur" - runs between transverse acetabular ligament and fovea of femoral head -tubular sheath of synovial lined connective tissue -adds stability -carries small branch obturator artery
acetabular anteversion angle
-describes the extent to which the acetabulum surrounds the femoral head within the horizontal plane - normal is about 20 degrees and exposes part of the anterior side of the femoral head
sagittal plane function of hip adductors
-flexors or extensors based on hip position
what is the external hip capsule reinforced by
-iliofemoral ligament - pubofemoral ligament - ischiofemoral ligament
psoas minor
-little functional significance at hip absent in 40% of people
femoral on pelvic: rotation of femur in frontal plane
-on average hip abducts 40 degrees - hip adducts 25 degrees beyond neutral position
where does the acetabular ligament run
-projects laterally from pelvis with varying amount of inferior and anterior tilt
femoral neck projects ________ to ML axis through the femoral condyles
10-15 degrees anterior degree of torsion = normal anteversion
hips can be extended about ____ from teh 90 degree sitting posture through a _____ pelvic tilt
10-20 degrees posterior tilt of the pelvis
angle of inclination during adulthood
125
angle of inclination at birth
140-150
rectus femoris
2 joint muscle responsible for about 1/3 of the total isometric flexor torque at hip
infant typically born with ______ degrees of femoral anteversion
30 degrees
sitting upright with 90 degrees hip flexion, a normal adult can achieve about ___ additional pelvic on femoral hip flexion before being restricted by a completely extended lumbar spine
30 degrees
position of hip flexion decreases ER to ______
30-35 degrees
on average the hip IR _____ from neutral position
35 degrees
cancellous bone
3D lattice of trabeculae - tends to absorb stress - forms along the lines of stress
extended hip rotation about _____
45 degrees excessive tension TFL, ITB, lateral iliofemoral ligament may limit full ER
functional potential or IRs while walking: pelvic on femoral
IRs perform a subtle but important function during gait -in the stance phase, IRs rotate the pelvis in the horizontal plane over a relatively fixed femur
forces through hip are also transferred to what joint
SI and pubic symphysis
over time, in toeing may result in
a contracture of hip muscles, reducing hip ER ROM
what does the lumbar spine function as?
a mechanical decoupler it allows for independent pelvis and supralumbar trunk movement
pelvic on femoral rotation in the frontal plane
abduction of support hip adduction of support hip
which muscles are active to stabilize the pelvis during the stance phase of walking
abductors (glut med does most force)
which muscle group is capable of producing modest IR torque in anatomic position?
adductor
middle layer of hip adductors
adductor brevis
deep layer of hip adductors
adductor magnus
regardless of hip position, posterior fibers of _______ are powerful hip extensors
adductor magnus
by what age does anteversion decrease from 30 degrees to 15 degrees
age 6
in what planes do the hip adductors produce motion
all planes but primarily frontal and sagittal
compression on femur is dissipated ______
along posterior shaft
tension on femur is dissipated ______
along the anterior shaft
angle within the frontal plane between the femoral neck and medial side of femoral shaft
angle of inclination
the femur has a slight ________ convexity
anterior
glut med function
anterior fibers IR posterior fibers extend and ER
people with excessive anteversion of both femur and acetabulum are susceptible to
anterior joint dislocation, especially extremes of ER
medial rotation arthrokinematics
anterior roll, posterior glide
how is body weight displaced with a slight forward lean (PELVIC ON FEMORAL)
anterior to the ML axis of the hip
with a hip flexion contracture the line of force is ______ to the hip
anterior, creating a flexion torque so gravity acts as a hip flexor glut max must compensate
full hip extension increases passive tension in most ______
capsular connective tissues especially iliofemoral lig and hip flexors
what kind of joint is the hip joint?
classic ball and socket with 3 degrees of freedom
APT causes an increase in
compressive loads at the apophyseal joints bc of increased lumbar lordosis
what is the result of tight internal rotators
decreased external rotation
acetabulum
deep socket spanned by transverse acetabular ligament
when is the functional potential of ERs most evident
during pelvic on femoral rotation
slight IR, abduction and full extension results in what
elongation of some component of all the capsular ligaments
femoral on pelvic: extension
extension: 20 degrees beyond neutral position knee fully flexed = neutral position- passive tension rectus femoris
the lumbar spine _____ as the pelvis is tilted
flexes or flattens; iliofemoral and iliopsoas muscles are slightly elongated
when are the superior fibers of the ischiofemoral ligament taut
full adduction
when are the 3 ligaments of the hip all partially taut
full extension
primary hip extensors
glut max hamstrings posterior head of adductor magnus
primary abductors
glut med glut min TFL
coxa valga
greater than 125
excessive anteversion
greater than 15 degrees
is the closed packed position of the hip associated with its position of maximal joint congruency
hell no
what does standing or walking with partially flexed hip cause?
higher regions of pressure through thinner cartilage
force couple for PPT when supralumbar trunk help stationary
hip extensors and abdominal muscles
sartorius
hip flexion, ER, and abduction
APT force couple
hip flexors and low back extensor muscle
external rotation of support hip
iliac crest on side of non- support hip rotates backward in horizontal plane
iliopsoas
iliacus and psoas major - potent hip flexor both femoral on pelvic and pelvic on femoral - iliacus: anterior tilt the pelvis, accentuate lumbar lordosis -psoas major: excellent vertical stability of lumbar spine
when is the hip joint most congruent
in 90 degrees of flexion with moderate abduction and external rotation (much of the capsule and ligaments unraveled to a more slackened state)
hip flexed to 90 degrees, IR torque potential ______
increases
when are the inferior fibers of the ischiofemoral ligament taut
inferior fibers and portion of the inferior capsule are taut in full flexion
adduction arthrokinematics
inferior roll, superior glide
osteokinematics: femoral on pelvic flexion
knee fully flexed = 120 (squatting, tying a shoe lace) knee extended = 80 degrees - passive tension hamstrings and gracilis
femoral neck connects the femoral head to the shaft which displaces the proximal shaft of the femur
laterally
intracapsular pressure of a healthy hip is normally ________ than atmospheric pressure
less than
coxa vara
less than 125
retroversion
less than 15 degrees
what limits adduction when the rotating in the frontal plane
limited by interference with contralateral limb, passive tension in stretched hip abductor muscles, ITB, and superior fibers ischiofemoral ligament
what limits abduction of hip when rotating in the frontal plane
limited primarily by pubofemoral ligament, adductor and hamstring muscles
adduction of support hip
lowering iliac crest on the side of nonsupport motion cause slight normal concavity within lumbar region on the side of the adducted hip
femoral head contacts along horse shoe shaped ______ surface
lunate
distal to the neck the femur courses slightly
medial
what is the forward lean restrained by (pelvic on femoral)
minimal action of the glut max and hamstring- greater activation of hamstirngs
frontal plane function of hip adductor
most obvious function is production of adduction torque for both femoral on pelvic and pelvic on femoral
a straight leg raise requires the rectus abdominus to generate ____ in order to neutralize the strong _____
must generate potent PPT to neutralize the strong APT potential of hip flexors
are there any primary IR of hip
nope
hip joint forces provide stimulus for what
normal development of joint shape in childhood
pelvic on femoral: ipsilateral lumbopelvic rhythm
occcurs as pelvis and lumbar spine rotate in the same direction
pelvic on femoral: contralateral lumbopelvic rhythm
occurs as pelvis rotates in one direction and the lumbar spine rotates in opposite direction
during internal rotation the lumbar spine must rotate (twist) in the ______ direction of the rotating pelvis
opposite
in ER the lumbar spine must rotate in________ direction of rotating pelvis
opposite
the cane goes _____ the affected hip
opposite- it reduces the joint forces caused by activation of hip abductor muscles
someone with capsulitis will be most comfortable in what position?
partial flexion because there is less pressure on the hip. this can be problematic as it will cause shortening of the hip flexors
superficial layer of hip adductors
pectineus adductor longus gracilis
function of hip flexors: pelvic on femoral
pelvic on femoral: APT
function of hip flexors: femoral on pelvic
performed through synergy between the hip flexors and abdominal muscles
primary ER muscles
piriformis obturator internus gemellus superior gemellus inferior quadratus femoris glut max sartorius
secondary abductors
piriformis sartorius
what is the closed packed position of the hip
position of extension, internal rotation, and abduction (elongates the ligaments so closed packed)
when standing normally, the force of the body weight is _______ to ML axis of hip
posterior (hip extensor torque)
secondary ER muscles
posterior fibers glut med and min long head of biceps femoris obturator externus
secondary hip extensors
posterior fibers of glut med
lateral rotation arthrokinematics
posterior roll, anterior glide
TFL
primary flexor and abductor of the hip; secondary IR
relatively low pressure creates partial suction that
resists distraction of hip. this adds an extra element of stability
in what plane is the largest torque produced
sagittal
full anterior tilt slackens ____ and elongates _____
slackens iliofemoral ligament and elongates the inferior capsule
full hip flexion slackens _____ but stretches __________
slackens most ligaments stretches inferior capsule
flexion/extension arthrokinematics
spin
during the ______ phase of walking, the lunate flattens slightly as acetabular notch widens, resulting in _______
stance phase -increasing contact area and reducing peak pressure -want a larger contact area to dissipate forces
when are the superficial fibers of the ischiofemoral ligament taut
superficial fibers are taut in full internal rotation and extension
abduction arthrokinematics
superior roll, inferior glide
full extension of hip (about 20 degrees beyond neutral) twists or spirals much of the capsular ligaments to their most _____ position
taut
when is the pubofemoral ligament taut
taut in hip abduction and extreme extension
which side should you carry a load on if you have hip problems
the affected side
what innervates the muscles of the anterior and medial thigh
the lumbar plexus (T12- L4); femoral and obturator nerves
what innervates the muscles of the posterior and lateral hip, posterior thigh, and the entire lower leg
the sacral plexus (L4-S4) sciatic nerve
what happens if the center edge angle decreases
there is less coverage of the femur and an increased risk of dislocation
describes the relative rotation "twist" between the shaft and neck of femur
torsion angle
true or false: a disrupted labrum means you are more likely to sublux or dislocate the hip
true
true or false: the entire surface of the femoral head is covered with articular cartilage except for the region of fovea
true
innominate
union of the ilium, pubis, and ischium
compact bone
very dense and unyielding, withstand large external loads
in toeing
walking pattern with excessive hip internal rotation - compensatory mechanism used to guide excessively anteverted head more directly into acetabulum