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What type of joint is the iliofemoral joint?
ball and socket w/ 3 axes of rotation
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What are the 3 axes of rotation at the iliofemoral joint?
lateral, longitudinal, anterior/posterior
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Lateral axis of the iliofemoral joint:
- passing through center of femoral head--directly in line w/ top of palpable greater trochanter of femur
- Motion-flex/ext
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Longitudinal axis of the iliofemoral joint:
- this mechanical axis, is an imaginary line passing through the center of the hip and knee joints
- Motion-internal/external rotation
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Anterior/posterior axis of the iliofemoral joint:
- passing through the center of femoral head-at the groin-midpoint of inguinal line
- Motion-abd/add
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The in-utero position of the hip is in:
- flexion, abduction, and external rotation
- ligaments form and tighten initially in this position
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As children develop, bear weight, and begin standing, the hips slowly move into:
extension and into neutral with regard to rotation, however the ligaments retain their twisted shape, adding to hip stability (
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What motion does the iliofemoral ligament limit?
extension
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What limits external rotation of the hip?
lateral fasciculus
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What motion does the pubofemoral ligament limit?
abduction and extreme extension
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What motion does the ischiofemoral ligament limit?
internal rotation and extension
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**The majority of the 3 hip ligaments' fibers are elongated at the joint's close-packed position of combined:
- full extension (20 degrees past neutral)
- slight internal rotation
- abduction
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In open chain, when convex femoral head moves on stationary concave acetabulum, during hip flexion:
roll-
glide-
the femur rolls superiorly/anteriorly and glides inferiorly/posteriorly
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In open chain, when convex femoral head moves on stationary concave acetabulum, during hip extension:
roll-
glide-
the femur rolls superiorly/posteriorly and glides inferiorly/anteriorly
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In open chain, when convex femoral head moves on stationary concave acetabulum, during hip abduction:
roll-
glide-
femur rolls superiorly/laterally and glides inferiorly/medially
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In open chain, when convex femoral head moves on stationary concave acetabulum, during hip adduction:
roll-
glide-
femur rolls inferiorly/medially and glides superiorly/laterally
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In closed chain when the concave acetabulum (and entire pelvis!) moves on a stationary convex femoral head, during hip flexion:
roll-
glide-
acetabulum rolls anteriorly and glides anteriorly
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In closed chain when concave acetabulum moves on stationary convex femoral head, during hip extension:
roll-
glide-
acetabulum rolls posteriorly and glides posteriorly
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In closed chain when concave acetabulum moves on stationary convex femoral head, during hip abduction:
roll-
glide-
acetabulum rolls laterally and glides laterally
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In closed chain when concave acetabulum moves on stationary convex femoral head, during hip adduction:
roll-
glide-
acetabulum rolls medially and glides medially
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In all movements of the hip in closed chain, the acetabulum rolls and glides:
inferiorly
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acetabular labrum surrounds:
the rim of the acetabulum in the hip joint
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What is the labrum composed of?
fibrocartilage
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What is the purpose of the labrum?
to deepen the socket of the hip joint, providing additional stability
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Labral tears can be painful and compromise:
the integrity of the hip joint
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At the end of available passive movement into hip extension, abduction, and adduction further movement is limited by:
the 3 ligaments, making normal end feel ligamentous
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At the end of available passive movement into hip flexion, further flexion is limited by:
- the soft tissue approximation of the thigh against the abdomen, making the end feel one of soft tissue approximation
- in slender individuals, there is a ligamentous endfeel
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Hip flexion with simultaneous knee extension is usally limited by:
- the length of the hamstring muscles
- creates muscular end-feel
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Hip extension w/ simultaneous knee flexion is limited by:
the length of the rectus femoris and can also creat a muscular end feel
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Problems with the hip joint can originate from two problems:
- 1. Angle of Inclination of the hip joint --occurs in frontal plane
- 2. Angle of torsion/version of the hip joint
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Version:
occurs in transverse plane of hip joint and concerns twisting of femoral NECK w/in acetabulum
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Torsion:
occurs as a twist in the FEMUR itself --also in the transverse plane
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A normal angle of inclination of the the hip is about:
125 degrees
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Coxa Vara:
angles less than 125 degrees
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Coxa Valga
angles greater than 125 degrees
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Coxa vara/valga can alter normal hip biomechanics and/or lead to:
abnormal joint wear and tear or a leg length deformity
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Which one (coxa vara or valga) causes genu valgum (knee knock)?
coxa vara
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Anteversion or retroversion are angular measurements that relate the:
FEMORAL NECK position in the acetabulum (transverse plane)
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Anteversion:
- angle of head and neck of femur relative to frontal plane of body that is greater than 12 degrees
- represents normal femur abnormally positioned in the acetabulum
- toe pointed out
- head of femur forward (femur twisted out)
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Retroversion:
- angle of head and neck of femur relative to frontal plane that is less than 12 degrees
- represents normal femur abnormally positioned relative to acetabulum
- head of femur back
- toes point in
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What is another term for angle of torsion?
angle of declination (transverse plane)
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Angle of torsion:
angle b/w axis of femoral neck and line drawn b/w femoral condyles (a twist in femur) or the degree of torsion/rotation of the femoral neck in relation to the shaft of the femur
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Antetrosion:
- angle of torsion greater than upper range of "normal" (greater than 15 degrees)
- angle that head and neck of femur make with frontal plane of body is normal and Antetorsion results in internally deviated leg
- toes point in
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Retrotorsion:
- angle less than lower range of normal (less than 8 degrees)
- angle that head and neck of femur make w/ frontal plane of body is normal and retrotorsion results in externally deviated leg
- toes point slightly out
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Is torsion concerned with twisting of femur or angle of femur?
twisting
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Is version concerned with twisting of femur or angle of femur?
angle
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Ante-torsion and retroversion cause toe to point:
IN
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Anteversion and Retro-torsion cause the toes to point:
OUT
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Craig's test/Ryder's test/Test for Femoral Torsion:
- align greater trochanter in lateral most position so that it is parallel w/ the plinth
- correlates w/in 4 degree of radiographic measurements in children
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Developmental dysplasia of the hip:
- infants born w/ shallow acetabulum, or don't bear wt in standing often enough to develop deep acetabulum
- ligaments not taut, either from stress in development, or maternal hormones present after birth
- head of femur drifts superiorly and posteriorly b/c of instability
- intervention involves surgery or splinting/casting in abducted position
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What fractures can occur as people age?
- femoral neck hip fractures
- intertrochanteric fracture
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Femoral neck hip fracture:
- serious b/c blood supply to femoral head may be decreased
- may require total hip replacement
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intertrochanteric fracture:
- usually easier to repair
- age (over 60), osteoporosis and a risk of falling from balance loss all contribute to hip fractures
- serious injury in older individuals and extremely hard to rehab
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Arthritis or degenerative joint disease is characterized by:
progressive wearing away of cartilage of joint. As protective cartilage is worn away by hip arthritis, bare bone is exposed w/in joint
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When NAISIDS, range of motion exercise, assistive devices, rest, and modalitites don't alleviate pain and reduce disabiltiy, doctors may recommend a:
total joint replacement
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Muscles that move the hip
Hip Flexors
- iliopsoas**
- rectus femoris
- tensor fascia latae
- sartorius
- pectineus
- anterior fibers of gluteus medius
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Muscles that move the hip...
Hip Abductors:
- gluteus medius**
- gluteus minimus
- upper fibers of gluteus maximus
- sartorius
- tensor fascia latae
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Muscles that move the hip...
Hip Adductor Group:
- adductor magnus
- adductor longus
- adductor gracilis (2 joint)
- adductor brevis
- pectineus
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Muscles that move the hip...
Hip Extensors:
- gluteus maximus
- biceps femoris
- semitendinosus
- semimembranosus
- posterior fibers of gluteus medius
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Muscles that move the hip...
Hip internal (medial) rotators:
- tensor fascia latae
- gluteus minimus
- adductor group
- anterior fibers of gluteus medius
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Muscles that move the hip...
Hip extenral (lateral) rotators:
- piriformis
- gemellus (superior and infeiror)
- obturator internus and externus
- quadratus femoris
- posterior portion of gluteus medius
- gluteus maximus
- sartorius
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What moments does gravity's force produce at hip in standing in sagittal plane?
- normal standing posture, center of gravity of mass superincumbent to hip joint is located so that its line of application passes posterior to hips lateral axis
- gravity's force, acting at a distance from the axis of hip joint, produces posterior pelvic tilt. In closed chain, w/ femur fixed, as posterior pelvic tilt produces hip extension.
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What controls gravity's hip extensor moment?
hip flexor muscle activity
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What moments does gravity's force produce at hip in standing?
- the idea that we activate mm that oppose gravity's moment makes sense in terms of rotational equilibrium
- However,
- we need not use mm to stabilize hip joint during normal quiet standing, b/c anterior ligament exists w/ same line of application
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When iliofemoral ligament elongates, like a very tight spring, it develops an elastic force. Although this force is passive, not active like a muscle's force, it is nevertheless:
directed at its points of attachment on th ilium and femur. The force prevents attachments from being pulled further apart, that is, prevents extension. A vector that represents ligamentous force looks exactly like force in hip flexor m.
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What moments does gravity's force produce at the hip in standing in the frontal plane?
- abd/add
- gravity-R. hip add (left side drops)
- b/c stance phase of walking occurs in closed kinetic chain, analyze R hip movement by considering mass superincumbent to joint as moving part
- force of gravity, the wt of the mass produces adduction of R hip
- (mm oppose gravity=abd (glut med)
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What controls gravity's adductor moment?
pelvises don't drop dramatically on the non-stance side b/c gravity's adductor moment is balanced by an equal and opposite abductor moment
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A major fxn of the hip abductors is:
in closed-chain motion to maintain a level pelvis in unilateral stance
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How does one compensate for gluteus medius weakness?
- hip abductor activity necessary to stabilize hip in frontal plane during unilateral stance, people w/ hip abductor weakness have problem
- may see pelvic drop on unsupported side if we ask person to stand on weak limb.
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positive Trendelenburg sign:
inability to maintain a level pelvis in unilateral stance
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B/c permitting pelvis to drop on unsupported side when one walks is to risk a fall, few people do it. Instead, most people try to achieve:
- rotational equilibrium
- Fgsg=Fmsm
- by decreasing sg, the moment arm associated w/ gravity's force on mass above hip. Decreasing sg/shortening gravitational force's moment arm, decreases magnitude of gravity's adductor moment, and so decreases force demanded of weak muscle
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The most direct way to reorient line of application of gravity vector and so to shorten its moment arm w/ respect to hip joint, is to:
lean trunk toward side of hip whose abductor mm are weak.
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Trendelenburg gait pattern (gluteus medius limp)
person leans laterally during stance
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The secret in using an assistive device, like a cane, is to create additional force that keeps the pelvis level in the face of gravity's tendency to adduct the hip during unilateral stance. the cane's force must substitute the hip abductors
A force that levels the pelvis efficiently, b/c its moment arm is long, is directed upward from a point of application on pelvis. Force originates on side opposite hip whose abductor mm are weak
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To produce a force w/ a cane, one must push the can firmly into ground in vertical direction. Doing so generates an upward reaction force whose magnitude equals downward force one exerts on cane
Additionally, person needs adequate strength in muscles of wrist, elbow, shoulder girdle, and trunk, whose effect is symbolized by dashed line that connects vectors R and C. If not, he or she can't efficiently transfer cane's vertical reaction force to top of pelvis where it is needed
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