Hip Flashcards
What is angle of inclination and normal value?
Frontal plane angle between a line bisecting the neck of the femur and a line bisecting the shaft. (120-135 degrees)
What type of joint is the hip?
Enarthrodial joint
Angle of inclination at birth
150 degrees and normally degreases to 125 at adulthood
Coxa vara
Angle of inclination <120. Increases tension force on the femoral neck.
Coxa valga
> 135 angle of inclination. Increases compression force on the femoral head.
Angle of torsion
Angle formed between a line bisecting the neck of the femur and a line parallel to the plane of the shaft of the femur. (8-12 degrees normal). Also allows the femoral condyles to face anteriorly.
Normal antetorsion
8-12 degrees
Anteversion
> 12 degrees (excessive angle) “in toeing”
Increased: anterior exposure, chance of dislocation, labral lesions and chances increase even more with excesssive femaoral anteversion
Retroversion
toes pointed out and decreased angle or torsion
Femoralacetabular joint
Diarthrodial spheroidal joint (ball and socket joint)
Articulation of the convex femoral head with the concave acetabulum.
Zona orbicularis
A band of circular fibers ghat enclose the neck of the femur (stronger anteriorly)
What structure covers the head of the femur and increases the articular surface of acetabulum by 10%?
Labrum
Iliofemoral ligament
AKA ligament of bigelow or “Y” ligament
From AIIS to intertrochanteric line
Strongest….prevents hyperextension and ER
Pubofemoral ligament
From the pubis to the intertrochanteric line
Limits abduction and ER
Ischiofemoral ligament
Attaches from posterior acetabulum to trochanteric line
Limits IR
What are three ligaments that strengthen the hip joint capsule?
Iliofemoral (anterior)
Pubofemoral (anterior)
Ischiofemoral (posterior)
Bursae around the hip
Superficial and deep greater trochanter
Ischial bursa
Iliosoas bursa
Bursitis of the hip is evident most commonly in who?
Sedentary women between 40-60
What is the IT band?
Iliotibial band - thickened fascia meeting from the gluteus maximus and TFL that runs along the lateral hip and inserts below the knee (gerdy’s tubercle)
Arthokinematic surfaces of the hip
Motion occurs between the convex femoral head and concave acetabulum
How many degrees of freedom are at the hip?
3
Flexion/extension
Abduction/adduction
IR/ER
What is the primary motion of the femoral head?
Primary motion is a spin of the femoral head accompanied by a glide but is limited due to the size and shape of the joint
Femur on pelvis arthrokinetmatics
Flexion- spin and glide posteriorly and inferiorly
Extension- spin and glide anteriorly
Abduction-superior roll and inferior glide
Adduction-inferior roll and superior glide
IR-anterior roll and posterior glide
ER-posterior roll and anterior glide
Pelvis on femur arthokinematics
Flexion(spins)-anterior pelvic tilt
Extension(spins)-posterior pelvic tilt
Abduction(concave on convex)-ipsilateral tilt or contralateral shift
Adduction-contralateral tilt or ipsilateral shift
IR-ipsilateral posterior rotation & contralateral anterior rotation
ER-ipsilateral anterior rotation & contralateral posterior rotation
Lumbopelvic rhythm - ipsidirectional
Hip and spine moving in same direction
ex/ bending over
Lumbopelvic rhythm - contradirectional
Hip and spine moving in opposite direction
Ex/ standing up straight, sitting, walking-hip flexes/back extends
Allows for decoupling of the upper and lower areas of the body
Closed position of hip
Full hip extension
Slight IR
Slight ABD
Open position of hip
30 degree hip flexion
30 degrees hip abduction
Slight ER
Capsular patter of hip
Flexion, abduction, and IR > extension
2 joint muscles have a greater effect on which joint?
Greatest effect on distal joint ex/ rectus femoris is a better knee extensor than hip flexor
What is the exception to the 2 joint muscles?
Sartorious is a better hip flexor than a knee flexor
Tight hip flexors cause ________ pelvic tilt and _____lumbar lordosis?
Anterior/increase
What muscles are the primary hip flexors?
Iliopsoas, sartorious, rectus femoris, TFL, pectinous
What muscles are the primary hip extensors?
Glut max, hamstrings, glut med, piriformis
What muscles are responsible for anterior pelvic tilt?
Hip flexors-psoas major, iliacus, sartorius
Erector spinae
What muscles are responsible for posterior pelvic tilt?
Trunk flexors-rectus abdominis, external oblique
Hip extensors-glut max and hamstrings
What is the function of the hip abductors?
Stabilize pelvis and hips while walking
Weak hip abd associated with back and knee problems
What is the function of hip adductors?
Create motion in all 3 planes
Assist primary hip flexors and extensors to produce a more forceful stride in running and cycling
What is the function of the hip internal rotators?
Rotate the pelvis over the femur during stance phase which causes the opposite leg to move anteriorly
What is the function of the hip external rotators?
Most active during change of direction activites when the leg is planted and ER body away from the leg
Commonly weak in LE injuries
What muscle is the most powerful ER?
Gluteus maximus
Straight leg raise stabilization sequence?
A) normal activation of RA stabilizes pelvic position and maintains normal lumbar curve
B) decreased activation of rectus abdominis fails to stabilize pelvic position allowing hip flexors (anterior pelvic tilt) to increase lumbar curve
What structure is important in maintaining normal hip extension functionally?
Pelvic position in standing is maintained by the iliofemoral ligament tension
What causes decreased hip extension functionally?
Not able to actively contract hip extensors muscles to maintain pelvic position in neutral and very tight iliofemoral ligament with tight ilioosoas
What can decreased hip extension cause?
Increased compression between acetabulum and head of femur
Dual action and stability of adductor longus
Adductor longus is capable of hip extension when hip is flexed and hip flexion when hip is extended due to positional leverage
What is the benefit of dual action and stability of the adductor longus?
Allows for frontal plane stabilty secondary to constant activation during running/gait because of adduction force present in both positions
Obturator internus sling
Obturator internus forms a functional sling via lesser sciatic notch
Active contraction causes ER and increased joint compression between acetabulum and femoral head
What percentage of body weight does each hip hold during 2 leg standing?
33 percent (head, arms, trunk 66 percent)
What is the force on the hip during 1 leg standing?
About 2.5 times the BW (100% from BW, 150% from abductors)
What is an example of a static force?
Standing….force on the hip joint
When do dynamic forces occur?
Running, walking, motion, etc.
Generated from muscle activity and from the ground reaction force (due to gravity)
How to use a cane?
Cane is held on opposite side of weakened/injured extremity and advanced with weakened limb
Why is a cane used as it is?
Wider base of support
Improved balance
Follows normal rhythm of gait
Decreases load weight bearing injured extremity
What is the american college of rheumatology diagnostic criteria for hip osteoarthritis?
Hip pain, less than 115 degrees hip flexion, and <15 degrees IR
Hip osteoarthritis
Occurs in 10-20% of aging population. Primarily cause is unknown but mechanical disruption with abnormal arthrokinematics such as in toeing could be a cause if known.
What is femoral acetabular impingement?
When the femur impinges on the acetabulum
What are the two types of femoral acetabular impingment?
Cam-shear forces on acetabular rib and jamming of femoral head against acetabulum…more common in repetitive activites (running/jumping)
Pincer- impingement between acetabulum and femoral head-neck junction and seen with acetabular retroversion….more common with extreme ROM (gymnasts, yoga)
What are some signs and causes of femoral acetabular impingement?
Hip pain, weakness, catching/clicking, groin pain
Results in damage to labrum and fibrocartilage at the hip
Often corrected with surgery
What is slipped capital femoral epiphysis?
Common in adolescents
Obesity a factor
Accurate diagnosis and immediate intervention is critical
Results form a salter-harris fracture
Associated with retroversion of the hip and coxa vara (increased shear forces at the hip)
Surgery may be required
