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