Gluteal Region Flashcards
OINF Obturator Internus
Origin- inner surface of obturator membrane and rim of pubis and ischium bordering membrane
Insertion: middle part of medial aspect of greater trochanter of femur
Action: laterally rotates and stabilizes thigh
Nerve: nerve to obturator internus (L5, S1, 2)
OINF Gemellus superior
Origin: spine of ischium
Insertion: middle part of medial aspect of greater trochanter of femur
Action: laterally rotates and stabilizes thigh
Nerve: nerve to obturator internus (L5, S1,2)
OINF Gemellus Inferior
Origin: upper border of ischial tuberosity
Insertion: middle part of medial aspect of greater trochanter of femur
Action: laterally rotates and stabilizes thigh
Nerve: nerve to quadratus femoris (L4,5, S1)
What are the short lateral rotators?
gemellus superior, gemellus inferior, obturator internus
OINF Piriformis
Origin: 2,34 costotransverse bars of anterior sacrum (inside of pelvis), few fibers from superior border of greater sciatic notch
Insertion: anterior part of medial aspect of greater trochanter of femur
Action: laterally rotates and stabilizes thigh
Nerve: anterior primary rami of S1, 2 (“nerve to piriformis”)
OINF Gluteus minimus
Origin: outer surface of ilium between middle and inferior gluteal lines
Insertion: anterior surface of greater trochanter of femur
Action: abducts and medially rotates thigh. Tilts pelvis on walking
Nerve: superior gluteal nerve (L4,5, S1)
OINF Gluteus medius
Origin: outer surface of ilium between posterior and middle gluteal lines
Insertion: posterolateral surface of greater trochanter of femur
Action: abducts and medially rotates thigh. tilts pelvis on walking
Nerve: superior gluteal nerve (L4,5, S1)
OINF Quadratus femoris
Origin: lateral border of ischial tuberosity
Insertion: quadrate tubercle of femur and a verticle line below this to the level of lesser trocanter
action: laterally rotates and stabilizes hip
Nerve: nerve to quadratus femoris (L4,5, S1)
OINF Gluteus maximus
Origin: ilium, sacrum, sacrotuberous ligament
Insertion: gluteal tuberosity, iliotibial tract
Action: extends and laterally rotates hip, aids in knee extension via iliotibial tract
Nerve: inferior gluteal L5, S1, S2
OINF Tensor Fascia Lata
Origin: outer surface of anterior iliac crest between tubercle of iliac crest and anterior superior iliac spine
Insertion: iliotibial tract (anterior surface of lateral condyle of tibia)
Action: maintains knee extended (assists gluteus maximus) and abducts thigh
nerve: superior gluteal nerve (L4,5, S1)
What are the roots of the sciatic nerve?
L4 L5 S1 S2 S3
Describe the following nerves (roots and relative location) superior gluteal n inferior gluteal n posterior femoral cutaneous n pudendal n
superior gluteal n (L4,5, S1) above piriformis
inferior gluteal n (L5, S1, S2) below piriformis
posterior femoral cutaneous n (S1,2,3)
pudendal n (S2,3,4) gives 3 branches (dorsal which is sensation to clitoris/penis, inferior rectal, and perineal which does all muscles and some sensory)
OINF Biceps femoris
Origin:
long head- upper inner quadrant of posterior surface of ischial tuberosity
short head- middle third of linea aspera, lateral supracondylar ridge of femur
insertion: styloid process of head of fibula. lateral collateral ligament and lateral tibial condyle
action: flexes and laterally rotates knee. long head extends hip (long head crosses knee AND hip joint too)
nerve:
long head- tibial portion of sciatic nerve
short head- common peroneal/fibular portion of sciatic
(both are L5,S1)
OINF Semimembranosus
Origin: upper outer quadrant of posterior surface of ischial tuberosity
Insertion: medial condyle of tibia below articular margin, fascia over popliteus and oblique popliteal ligament
action: flexes and medially rotates knee, extends hip
nerve: tibial portion of sciatic nerve (L5, S1)
OINF Semitendinosus
Origin: upper inner quadrant of posterior surface of ischial tuberosity
Insertion: upper medial shaft of tibia below gracilis
action: flexes and medially rotates knee. extends hip
nerve: tibial portion of sciatic nerve (L5, S1)
What four arteries make up the cruciate anastomosis?
in the upper thigh
inferior gluteal artery, lateral and medial circumflex femoral arteries, first perforating artery of profunda femoris artery
(FILM)
Why is the cruciate anastomosis clinically relevant?
if there is a blockage between the femoral artery and external iliac artery, blood can reach the popliteal artery by means of the anastomosis
What is the route of blood with cruciate anastomosis?
through internal iliac, to inferior gluteal artery, to lateral circumflex femoral artery, to an ascending perforating branch of the deep femoral artery, then to its descending branch into the superior lateral genicular artery and thus into the popliteal artery
What is the Tredelenberg sign?
What causes it?
buttock opposite gluteus medius weakness droops
pelvis tilts toward unaffected side
injury to superior gluteal nerve
…pt can abduct pelvis on left femur if lifting right foot (normal)
…pt unable to abduct pelvis on left femur so right buttock droops when lift right foot (Trendelenberg sign +)
Describe the posterior femoral cutaneous nerve
posterior femoral cutaneous (S1-3) (cluneal n to buttocks, perineal branch to perineum)
Describe the blood supply to the gluteal region.
(branches of internal iliac)
superior gluteal- superficial division ( to glut. max.) deep division to glut med. and minim.
inferior gluteal: muscular
cutaneous, coccygeal, sciatic
Describe the sciatic nerve.
From greater sciatic foramen, descends midway between the ischial tuberosity and the greater trochanter, subcutaneous at lower border of gluteus maximus, then travels deep to hamstrings
tibial nerve-preaxial
supplies hamstrings and posterior part of adductor mangus (ventral divisions of L4-S3)
common peroneal/fibular =postaxial, supplies short head of biceps femoris
What is the blood supply of the posterior thigh?
perforating branches of profunda femoris
What is the popliteal fossa?
What does it contain (from superficial to deep)?
diamond shaped space posterior to knee joint
contains fat, vessels nerves
from superficial to deep: sciatic nerve or its two main branches, popliteal vein (receives saphenous vein here), popliteal artery and its branches (superior medial and lateral genicular, inferior medial and lateral genicular, middle genicular)
What are the boundaries of the popliteal fossa?
upper medial: semimembranosus and semitendinosus
upper lateral: biceps femoris m.
lower- two heads of gastrocnemius m.
floor- femur, articular capsule of knee joint, and fascia over popliteus m.
