Lower limb 1 - The gluteal region and hip joint Flashcards
What forms the pelvic girdle and what do they provide?
2 hip (innominate) bones and sacrum
provides - strong stable support for lower limbs
Where does each innominate bone articulate with the sacrum posteriorly?
at the sacra-ilio joint
Where does each innominate bone articulate with anteriorly?
pubic symphysis
Which 3 bones is the innominate bone derived from and what is the point where these 3 bones eventually fuse?
- ilium
- ischium
- pubic
acetabulum
What is the difference between a male and female pelvis?
Male
- pelvic inlet - heart shaped
- angle of 2 arms of pubic arch - small and acute
- ischial spines - project medially
Female - big enough to pass baby head
- pelvic inlet - circular
- angle of 2 arms of pubic arch - larger and obtuse
- ischial spines don’t project far medially
What type of cartilaginous joint is the pubic symphysis and what is it between?
secondary cartilaginous joint
between the 2 pubic bones
What is the articular surface of the pubic symphysis covered by and what is it connected by?
articular surface - hyaline cartilage
connected by - fibrocartilaginous disc
What are the functions of the pelvis?
- bear weight of the upper body when sitting and standing
- transferring weight from axial skeleton to lower appendicular skeleton when walking and standing
- provides attachments
- withstand forces of powerful muscles
STRONG
STABLE
SUPPORT WEIGHT
PROTECT ORGANS AND VESSELS
What is the pelvic girdle strengthened by?
ligaments attaching to the ischium of the innominate bone
- sacrotuberous ligament - ischial tuberosity
- sacrospinous ligament - ischial spine
What does the acetabulum of the innominate bone articulate with in order to form the hip joint?
head of femur
What type of joint is the hip joint?
strong
stable
ball and socket joint
What movements are possible at the hip joint and what are there corresponding myotomes?
flexion - L2,3
extension - L4,5
abduction - L5, S1
adduction - L1,2,3,4
lateral/external rotation - L5, S1
medial/internal rotation - L1,2,3
What are the structures that strengthen and stabilise the hip joint?
acetabular anatomy
fibrous capsule
ligaments - iliofemoral, pubofemoral, ischiofemoral
What are the superficial muscles of the gluteal region?
- gluteus maximus
- gluteus medius
- gluteus minimus
- tensor fascia lata
What is the iliotibial tract and what does it do?
thickening of fascia kata into a longitudinal band
stabalises knee during running
What are the chief abductors at the hip joint?
- gluteus medius and minimus
also prevent pelvis sagging on opposite side
Where does the piriformis muscle lie?
deep to gluteus maximus
Why is the piriformis key?
it is key in identification of vessels and nerves which pas through the greater sciatic foramen - superior and inferior to this muscle
How does piriformis exit the pelvis to reach the gluteal region?
greater sciatic foramen
Where does the sciatic nerve emerge from in relation to the piriformis?
on lower border of piriformis
Why are the gluteal muscles frequently used as a site of intramuscular injection and what must you be wary of when administering these injections?
as they are a large mass of muscle
damage to the sciatic nerve
Where is a safe place to perform intramuscular injections in the gluteal region?
upper outer quadrant of either gluteal region
What nerve, artery and vein pass superior to piriformis?
superior gluteal nerve
superior gluteal artery
superior gluteal vein
What nerves, arteries and veins pass inferior to piriformis?
nerves
- sciatic nerve
- nerve to quadratus femoris
- nerve to obturator internus
- posterior cutaneous nerve of the thigh
- pudendal nerve
- inferior gluteal nerve
- perforating cutaneous nerve
artery
- inferior artery
vein
- inferior gluteal vein
What are the structures that pass through the lesser sciatic foramen?
tendon of obturator internus
internal pudendal vessels
pundendal nerve
nerve to obturator internus
What are the muscles found in close proximity to the obturator nerve?
- obturator internus
- superior and inferior gemelli
- quadartus femoris
