Anatomy lecture 13: Hip and knee joints (pelvic gircle joints & foot muscles) Flashcards
Femoral head:
Forms 2/3 of a sphere of diameter 4-5cm.
Supported by the neck of femur
Axis runs:
-superiorly
-medially
-anteriorly
Angle of inclination:
head of the femur in adult:
125
Fovea:
impression on the head of the femur for the attachment of the round head.
Angle of anteverison:
head of the femur forms an acute angle of 10-30 degrees with femoral plane
Femoral anteversion:
determined by measuring the angle formed between the long ais of the femoral neck and line parallel to the dorsal aspect of the femoral condyles.
Anteversion:
Increase in angle: causes in-toeing, pigeon toes, as well as genu valgum
Retroversion:
Decrease in angle: out-toeing (external rotation) during standing and walking as well as genu valgum during standing
Acetabulum:
hemispherical and is bounded at the acetabular rim.
lunate surface of acetabulum: lined by horseshoe-shaped articular cartilage, interrupted inferiorly by the acetabular notch
Directed laterally, inferiorly, and anteriorly
Acetabular fossa:
permits movement of the ligamentum teres & importantly serves as a reservoir for synovial fluid when hip is heavily loaded.
When joint surfaces are decreased, synovial fluid returns to the joint space for lubrication and nutrition to the articular cartilages.
Acetabular labrum:
fibrocartilaginous ring at the acetabular rim
Transverse acetabular ligament (TAL):
attached to either side of the acetabular notch & labrum
Ligamentum teres (LT):
flattened fibrous band:
O: acetabular notch
(runs the floor of the acetabular fossa)
I: fovea femoris capitis
-embedded in fibro-adipose tissue
-lined w/ synovial membrane
-Extremely strong
Primary function: carry the vascular supply to the head of the femur
Iliofemoral ligament:
Y-shaped ligament w/ two thick borders (superior & inferior bands)
Covers hip anteriorly & superiorly
Pubofemoral ligament:
-anterior & inferior to hip
-limiting lateral rotation & abduction
Ishiofemoral ligament:
posterior & inferior, limiting rotation
Fibrous layer of the joint capsule:
-extension of the hip joint winds (increases the obliquity) pulling the femur tightly into the acetabulum, increasing stability of joint
-Flexion unwinds the fibers of the capsule
Active hip flexion w/ knee flexed:
70-120 by hamstrings
Active hip flexion w/ knee extended:
70-90 by hamstrings
Hyper extension of the hip:
Is limited to 10-20 by iliofemoral ligament .
when knee is flexed it is less because there is a loss of movement at the knee.
Hip abduction:
45 degrees and usually accompanied by the elevation of the pelvis
Hip adduction:
contact between the two thighs or 0 degrees
legs crossed: 30-40 degrees
Medial rotation of hip:
30 degrees
Lateral rotation of hip:
60 degrees
Flexor muscles of the hip:
1) Psoas major
2) Iliacus
3) Sartorius
4) Rectus femoris
5) Tensor fascia Latae
6) Pectineus
7) Adductor longus
8) Gracilis
9) Anterior fibers of glutei Medius & minimus
First group produces flexion, abduction, and med. rot. (9, 5)
Second group produces flexion, adduction, and lat. rot. (1,2,6,7)
First group of extensor muscles of the hip:
1) gluteus maximus
2) posterior fibers of gluteus Medius
3) posterior fibers of gluteus minimus
(all inserted into femur)
Second group of the extensor muscles of the hip:
4) biceps femoris
5) semitendinosus
6) semimembranosus
7) adductor magnus
(inserts at the vicinity of the knee joint)
Abductor muscles of the hip:
1) anterior fibers of the gluteus medius
2) Gluteus minimus
3) Tensor fascia Latae
4) Gluteus maximus (upper fibers)
5) piriformis
In certain positions other muscles can contribute to the fore of abduction:
-Sartorius
-Obturators
-Gemelli
Adductor muscles of the hip:
1) adductor magnus
2) Gracilis
3) Semimembranosus
4) Semitendinosus
5) Biceps femoris
6) gluteus maximus
7) quadratus femoris
8) Pectineus
9) Obturator externus
10) Adductor longus
11) Adductor brevis
Lateral Rotator muscles of the hip:
1) piriformis
2) Obturator internus
3) Obturator externus
4) Quadratus femoris
5) Gluteus maximus
6) Gluteus Medius
7) Gemelli
Medial rotator muscles of the hip:
1) tensor fascia Latae
2) gluteus minimus (anterior fibers)
3) gluteus Medius (anterior fibers)