Ch. 21: Gluteal and Posterior Femoral Regions Flashcards
Gluteus Maximus
O: b/w posterior crest of ilium and posterior gluteal line and sacrotuberous ligament
I: gluteal tuberosity of femur and iliotibial tract
A: Extension, lateral rotation of thigh. Action on ITT with tensor fascial latae stabilizes knee
N: INferior gluteal n.
important going up stairs or getting up from sitting
Gluteus Medius
“deltoid of lower limb”
O: ilium b/w postioer and anterior gluteal lines
I: greater trochanter of femur
A: abduction of thigh
- Posterior fibers: act with glut. maximus to laterally rotate thigh
- Anterior fibers: act with gluteus minimus medially rotate thigh
- levels sacral base when opposite limb is unsupported
N: Superior gluteal n.
Gluteus Minimus
underneath glutius medius
O: ilium b/w anterior and inferior gluteal lines
I: greater trochanter of femur - anterior surface
A: abduction and medial rotation of thigh: actis with gluteus medius in leveling sacral base
N: superior gluteal n.
Tensor Fascia Lata
important for bracing and butressing the knee
O: anterior outer portion of iliac crest next to ASIS
I: iTT to lateral tibial condyle
A: Abducts, flexes, medially rotates thigh; by tensing ITT maintains knee in extended position
N: Superior gluteal n.
Piriformis
almost at 12’oclock position like supraspinatus
O: anterior surface of sacrum, lateral to anterior sacral foramina
I: greater trochanter of femur
A: Abduction of thigh, lateral rotation of thigh
Hip Drop condition
Gluteus Medius/Superior Gluteal N. (L 4, 5, S1)
Gemellus Superior
lateral rotation of thigh
N: nerve to obturator internus
Obturator internus
A: lateral rotation and abduction of thigh
N: nerve to obturator internus
Gemellus inferior
A: Lateral rotation of thigh
N: nerve to quadratus femoris
Quadratus Femoris
A: lateral rotation of thigh
N: nerve to quadratus femoris
Biceps Femoris
O: long head- ischial tuberosity; short head- inea aspera of femur
I: lateral condyle of tibia, head of fibula
A: both flex the leg, long head extends the thigh
N: long head = tibial component of sciatic n. ; short head = common fibular n.
Semimembranous
O: Ischial tuberosity
I: posterior surface, medial condyle of tibia
A: extends thigh, flexes leg and medialy rotates leg when kee is flexed (especially good for navigating directional change)
N: Tibial component of sciatic n.
Semitendinosus
O: Ischial tuberosity
I: medial anterior surface of tibia below condyle
A: extends thigh, flexes and medially rotates leg when knee is flexed
N: tibial component of sciatic
Pes Anserinus
medial, anterior aspect of tibia inferior to medial tibial condyle
- sartorius, gracilis and semitendinosus attach here
Superior gluteal a.
- branch of internal iliac a.
- passes through greater sciatic foramen superior to piriformis muscle
Divisions:
- Superficial: to gluteus maximus
- Deep: divides into superior and inferior branches, both go to gluteus medius and minimus
Inferior Gluteal a.
- branch of internal iliac a.
- passes to gluteal area from pelvic cavity via greater sciatic foramen inferior to piriformis muscle
Branches:
- muscular (to gluteus maximus)
- anastomotic branch (to cruciate anastomosis)
- branch to sciatic n.
- Coccygeal (pierve sacrotuberus ligament to gain gluteus maximus)
- cutaneous (accompany posterior femoral cutaneous n.)
Sacaral Plexus
- composed of ventral rami of spinal nerves L4,5 - S1,2,3
- provides motor and cutaneous innervation to lower limb muscles of pelvis and perineum and skin of perineum
Superior gluteal n.
L4,5-S1
originates from sacral plexusand exits the pelvis via the greater sciatic foramen above the piriformis muscle in company with the superior gluteal artery and v.
- courses b/w glutues medius and minimus
- innervates gluteus medius, minimus, and tensor fascia lata muscles
Inferior Gluteal n.
L5-S1,2
- Originates from sacral plexus and exits pelvis via greater sciatic foramen ANTERIOR to piriformis in company with sciatic, pudendal, and posterior femoral cutaneous nn, inferior gluteal and internal pudendal vessles
- passes directly into gluteus maximus which it innervates
Sciatic n.
L4,5-S1,2,3
* goes to all flexors on posterior side
- largest peripheral nerve of body and principle nerve of sacral plexus
- contains two components:
- tibial: composed of anterior divisions of ventral rami
- common fibular: composed of posterior divisions of ventral ramia
- exits pelvis via greater sciatic foramen, passes anteriorally or through the piriformis muscle, superficial to deep lateral rotators and deep to gluteus max. to enter thigh
- in thigh it lies on posterior surface of adductor muscle, deep to hamstrings
- splits into tibial and common fibular
- tibial innervates semimenbranosus, tendinosus, and long head of biceps femoris, part of adductor magnus
- common fibular innervates short head of biceps femoris muscel