5: Pelvis and Hip - Mahoney Flashcards
2 joints of pelvis
symphysis pubis (synchondrosis)
sacroiliac (syndesmosis)
3 planes of motion in pelvis
SAGITTAL(anterior/posterior tilt)
FRONTAL
left lateral pelvic tilt (left side moves upward)
right lateral pelvic tilt (right side moves upward)
TRANSVERSE
left transverse pelvic tilt (left side moves posterior)
right transverse pelvic tilt (right side moves posterior)
angle of inclination of femur in infant and adult
Infant-150°
Adult-125°
angle in the FRONTAL plane formed by the axis of the head and neck of the femur and shaft of the femur
define coxa vara and coxa valga
Coxa vara: a decrease in the angle of inclination so that the distal femur is directed towards the midline and the knees are closer together (genu valgum)
Coxa valga: an increase in the angle of inclination so that the distal femur is directed away from the midline and the knees are farther apart (genu varum)
define varus and valgus
Varus: the distal end of the distal bone comprising a joint points towards the midline
Valgus: the distal end of the distal bone comprising a joint points away from the midline
what is the purpose of the normal inclination angle
The inclination angle allows abductors to function with a mechanical advantage as they counterbalance body weight in one-legged stance
Hip abductors should be as far laterally from the hip as possible to achieve muscle stability which is maximum when the child begins to stand
what is alsberg’s angle?
angle formed by a line through the epiphyseal plate of the neck of the femur and the long axis of the femur
normal = 41 degrees
Increase is coxa valga, decrease is coxa vara
angle in the transverse plane formed by the axis of the neck of the femur and the transcondylar axis of the knee with the apex of the angle lateral
Angle of Declination of Femur
normal angles of declination of femur
Infant-30° to 60° of internal rotation (normal internal femoral shaft rotation known as FEMORAL ANTEVERSION)
Adult-8° to 12° of internal rotation
Therefore, angle decreases about 20°-50° by rotating externally, but still remains internally rotated by about 10° in the adult
The angle of declination:
- is formed by the axis of the neck of the femur and the shaft of the femur
- Is internally positioned at birth
- Decreases as the child ages
- A and B
- B and C
5
1 = angle of inclination
Hip Abductors: Orange Gorillas Go To Pais
obdurator internus gluteus minimus gluteus medius tensor fascia lata piriformis
Hip Adductors: Golfers Often Quit After Putting Grimly
gluteus maximus obturator externus quadratus femoris adductors pectineus gracilis
Hip Flexors: Poor Individuals Really Suffer
psoas major
iliacus
rectus femoris
sartorius
Hip Extensors: Giant Birds Swarm Seattle
gluteus maximus
biceps femoris
semimembranosus
semitendinosus
Knee Flexors: Some Students Believe Gross Sucks
semimembranosus semitendinosus biceps femoris gracilis sartorius
Knee Extensors: Vegas Virgins Very Rare
vastus medialis
vastus lateralis
vastus intermedius
rectus femoris
External Hip Rotators: Go Out And Get Some Quality Players
gluteus maximus obdurators adductors gemelli sartorius quadratus femoris piriformis
Internal hip rotators
gluteus medius and gluteus minimus
normal fetal position
like buddha
hips and knees flexed, hips externally rotated, knees and ankles internally rotated.
When the HIP is flexed in utero, it is also externally rotated; When the LOWER LIMB is flexed in utero, it is also internally rotated
This uterine position leads to:
- an increase in external rotation and flexion of the hip
- femoral anteversion caused by femoral head and neck rotating towards the anterior shaft of the femur-allows maximal rotation of hip in flexed position
_________ is created from the adducted position of the femur
angle of inclination
While the ______ femur externally rotates (decrease in angle of declination), there is a simultaneous inward rotation of the thigh in the region of the hip in the _____ around the hip (ligaments and muscles that attach into the hip
bony
soft tissue
The end result is that the knee is eventually pointed straight ahead in gait
The 8 to 12° of femoral anteversion is balanced by the external rotation of about 10° caused by normal soft tissue contraction at the hip as one progresses from infancy
define neutral position
Position from which a maximum excursion of the range of motion of the joint, any joint, can occur in either direction
what is the neutral position of hip?
that position in which the hip is neither externally rotated nor internally rotated
Calculating NFP neutral femoral position
- Add the amount of external hip rotation to the amount of internal hip rotation
- Divide by 2 (in the normal adult hip, for every degree of external rotation, there is one degree of internal rotation: 1:1 relationship)
- Subtract this value from the maximum amount of external hip rotation
- Perform this with the hip flexed and hip extended
- Neutral position of the hip that is internal will have a hip that has more rotation internal than external
- Opposite for neutral position of the hip that is external which will have more external rotation than internal
When the NFP is the ______ with the hip flexed and hip extended, the rotation is due to a twist or torque in the femur, itself
same
When the NFP is _________ with the hip flexed and hip extended, the rotation is due to a soft tissue contracture, usually in the hip joint itself
different
A NFP that is internal means that the foot will point _______
inwards
A NFP that is external means that the foot will point outwards
*** normal hip external and internal rotation values
Infants: 60-90° external; 0-30° internal (3:1)
Up to 1 year: 50-60° external; 30° internal (2:1)
4 years to adult: 45° external; 45° internal (1:1)
normal hip rotation is performed with the hip flexed (tightens primarily the ischiofemoral ligament) and knee flexed. If shortened or taut, the range of hip motion will …
decrease internally (usually), so you have an increase of external hip rotation
and with the hip extended (tightens the iliofemoral, pubocapsular, and ligamentum teres ligaments) and knee flexed. If shortened or taut, the range of hip motion will decrease externally (usually) and will increase internal hip rotation
With HF, tighten the ischiofemoral ligament (limits internal rotation or promotes external rotation)
With HE, …
tighten the iliofemoral and pubofemoral ligaments (limits external rotation or promotes internal rotation)
the NFP is not 0. Why?
– >If there is no change in amount of hip rotation with the hip flexed and extended, the cause is bony (a lack of enough external rotation of the femoral shaft or too much external rotation of the femoral shaft).
– > If there is a change with the hip extended and flexed, it is due to tightness of the ischiofemoral ligament (if it is external NFP) or due to tightness of the iliofemoral, pubocapsular or ligamentum teres (if it is internal NFP).
The neutral femoral position of the hip with the hip extended is 8° internal. The neutral femoral position of the hip with the hip flexed is 4° internal. The most likely cause is: Tight medial hamstrings Internal torsion of the femur External torsion of the femur Tight ligamentum teres Tight ischiofemoral ligament
tight ligamentum teres
what are the normal ranges of motion in the sagittal plane of hip?
Hip flexion: at least 120°-130°
Hip extension: 0-20°
what are the normal ranges of motion in the frontal plane motion of hip
Hip abduction: 40-45°
Hip adduction: 20-25
(2:1) in adult
how do you test for a tight medial hamstring?
To test for a tight medial hamstring (which leads to an in-toe gait or a patella that tracks medially):
- with patient supine, flex the hip and knee to 90° and maintain this position
- externally rotate the lower leg (pointing the toes externally) as you gradually extend the knee
- medial tightness will be manifested by the examiner unable to achieve 160° of knee extension
Lateral hamstring tightness (leading to an out-toe gait or lateral tracking patella) is tested by internally rotating the lower leg (pointing the toes internally) as you extend the knee
Match the correct pairs of normal positions or values:
- Hip extension 20°, hip flexion 120°
- Hip adduction 40°, hip abduction 20°
- Coxa varum, genu valgum
- Increase in external rotation of hip due to tight hip abductors
1 and 3
