Muscles of the Gluteal Region & Lateral Rotators

the gluteal region

prominent area posterior to the pelvis and inferior to the level of the iliac crest, extends laterally to the post margin of the greater trochanter

muscles of the gluteal region info (3)

• divided into 2 layers

• move femur

• originate on the pelvic girdle and insert on the femur

muscles of glutea region divided into

• superficial (3)

• deep

gluteal muscle group (3)

• gluteus maximus

• gluteus medius

• gluteus minimus

gluteus maximus intro (4)

• most superficial

• powerful

• covers all gluteal muscles

• fibers run obliquely, inferiorly, and laterally at 45 deg

gluteus maximus origin (3)

• post sacrum & coccyx

• ilium: post to post gluteal line

• sacrotuberous lig

gluteus maximus insertion (2)

• deep ¼ of fibers → gluteal tuberosity of femur

• superficial ¾ of fibers → iliotibial band

gluteus maximus actions (2)

• hip ext

• lat rotation of extended hip

gluteus maximus functional anatomy (4)

• trunk upright from a seated position

• trunk down to seated position

• power movements: walking and running

• weakness causes ant pelvic tilt

gluteus maximus innervation

inferior gluteal nerve (L5, S1, S2)

gluteus maximus arterial supply

inferior gluteal and superior gluteal artery

gluteal bursae purpose

reduce friction and permit free movement

how many gluteal bursae are there

3

gluteal bursae (3)

• trochanteric bursa

• ischial bursa

• gluteofemoral bursa

trochanteric bursa location

b/w superior fibers of the gluteus maximus & greater trochanter

ischial bursa location

b/w inferior fibres of glutes max & ischial tuberosity

gluteofemoral bursa location

b/w ITB and superior prox attachment of vast lat ms

gluteus medius intro (3)

• deep to gluteus max

• triangular shaped

• fibers run inferior and lateral

gluteus medius origin

gluteal surface of ilium: b/w ant and post gluteal lines

gluteus medius insertion

greater trochanter of femur (laterally)

gluteus medius main ms actions (3)

• hip abd

• ant fibers= assist w medial rotation of hip

• post fibers = assist w ext & lat rotation of hip

gluteus medius functional anatomy (3)

• imp pelvic stabilizer during walking

• lack of stability results in trendelenburg gait

• maintains horizontal pelvic during single leg stance phase of walking

gluteus medius innervation

superior gluteal nerve (L4-S1)

gluteus medius arterial supply

superior gluteal artery

gluteus minimus intro (3)

• smallest

• fan shaped

• share actions with gluteus medius

gluteus minimus origin

gluteal surface of ilium: b/w ant and inferior gluteal lines

gluteus minimus insertion

greater trochanter of femur

gluteus minimus main actions (2)

• hip abd

• assists w med rotation and flex of hip

gluteus minimus innervation

superior gluteal nerve (L4-S1)

gluteus minimus arterial supply

superior gluteal artery

lateral rotators of the hip (6)

• piriformis

• obturator externus

• obturator internus

• superior gemelli

• inferior gemelli

• quadratus femoris

piriformis intro (3)

• pear shaped

• most superior of lat rotators

• forms pelvic wall

piriformis origin (2)

• anterior-lateral sacrum

• sacrotuberous lig

piriformis insertion

greater trochanter of femur

piriformis main actions (3)

• lat rotation of hip

• abd w flexed hip

• stabilizes femoral head in acetabulum

piriformis innervation

nerve to piriformis (S1, S2)

piriformis arterial supply

branches off the superior, gluteal, inferior gluteal and internal pedundal arteries

sciatica fact

lateral rotators may exert pressure on the sciatic nerve producing pain radiating into the lower extremity

obturator externus intro (3)

• flat, triangular ms

• belly lies deep to proximal thigh

• stabilizes head of femur

obturator externus origin (3)

• ant margin of the obturator foramen & inner 2/3 of obturator membrane

• superior pubic rami

• inferior pubic rami

obturator externus insertion

trochanteric fossa of femur

obturator externus main action (2)

• lat rotation of hip

• stabilizes head of femur in acetabulum

obturator externus innervation

obturator nerve - post branch (L2-L4)

obturator externus arterial supply

obturator artery & medial circumflex femoral artery

obturator internus intro (3)

• right angle out of pelvis

• bursa allows for free mvm

• forms triceps coxae w gemelli ms

obturator internus origin (2)

• post edge of the obturator foramen & membrane

• post aspect of ischium

obturator internus insertion

greater trochanter of femur

obturator internus main actions (3)

• lat rotation of hip

• assists in hip abd when hip is flexed

• stabilization of femoral head in acetabulum

obturator internus innervation

nerve to the obturator internus & superior gemellus (L5, S1, S2)

obturator internus arterial supply

branches off the superior gluteal, inferior gluteal, and internal pedundal arteries

superior & inferior gemelli intro (3)

• on either side of obturator internus

• superior is smaller of the 2 w horizontal fibers

• form a tricipital ms which occupies gap b/w piriformis and quadratus femoris

superior gemellus origin

ischial spine (dorsal)

superior gemellus insertion

greater trochanter of femur via tendon of obturator internus

superior gemellus main action (2)

• lat rotation of hip

• hip abd when hip is flexed

superior gemellus innervation

nerve to obturator internus & superior gemellus (L5, S1, S2)

superior gemellus arterial supply

branches off the superior gluteal, inferior gluteal, and internal pedundal arteries

inferior gemellus origin

ischial tuberosity (superior aspect)

inferior gemellus insertion

greater trochanter of femur via tendon of obturator internus

inferior gemellus main actions (2)

• lat rotation of hip

• hip abd when hip flexed

inferior gemellus innervation

nerve to quadratus femoris & inferior gemellus (L4, L5, S1)

inferior gemellus arterial supply

medial circumflex femoral artery

quadratus femoris intro (2)

• short, flat quadrangular

• inferior to obturator internus & gemelli

quadratus femoris origin

ischial tuberosity (lat border)

quadratus femoris insertion

quadrate tubercle

quadratus femoris main actions (2)

• lat rotation of hip

• assist in hip abd

quadratus femoris innervation

nerve to quadratus femoris & inferior gemellus (L4, L5, S1)

quadratus femoris arterial supply

inferior gluteal artery

muscles that insert on the greater trochanter (7)

• gluteus medius

• gluteus minimus

• piriformis

• obturator internus

• obturator externus

• superior gemellus

• inferior gemellus

neurovascular structures of gluteal region

all branch from the sacral plexus and leave the pelvis via greater sciatic foramen

except for the superior gluteal nerve…

they all emerge inferior to the piriformis

superior gluteal nerve location

runs superior to piriformis and b/w gluteus medius & minimus

superior gluteal nerve inn (3)

• gluteus medius

• gluteus minimus

• TFL

inferior gluteal nerve location

runs inferior to piriformis

inferior gluteal nerve inn

gluteus maximus

nerve to quadratus femoris & inferior gemellus location

runs deep to sciatic nerve

nerve to obturator internus & superior gemellus location

runs post to sacrospinous lig

posterior cutaneous nerve of thigh location

emerges from inf border of glute max, descending deep to TFL

posterior cutaneous nerve of thigh supplies (2)

• inferior buttocks region

• posterior thigh

pudendal nerve (S2-S4) location

enters perineum via lesser sciatic foramen

pudendal nerve (S2-S4) innervates

primary nerve to perineum

sciatic nerve location

branches off sacral pleuxs merge at the inferior border of piriformis ms

sciatic nerve info (3)

• supplies no structures in this region

• runs deep to glute max, midway through G.T and ischial tuberosity

• most lat structure emerging through greater sciatic foramen, inferior to piriformis

arteries supplying the gluteal region arise from the

internal iliac artery

gluteal region arteries (3)

• superior gluteal artery

• inferior gluteal artery

• internal pudendal artery

superior gluteal artery location

passes through greater sciatic foramen, superior to piriformis

superior gluteal artery divides

into superficial and deep branches

inferior gluteal artery location

passes through greater sciatic foramen, inferior to piriformis

inferior gluteal artery contains a

branch, artery to the sciatic nerve

internal pudendal artery location

passes through the greater sciatic foramen inferior to piriformis

internal pudendal artery immediately leaves gluteal region through

lesser sciatic foramen to supply the perineal region

structures passing through greater sciatic foramen (7)

• piriformis ms

• sciatic nerve

• sup & inf gluteal n + a

• nerve to quadratus femoris

• post cutaneous nerve of thigh

• nerve to obturator internus ms

• pudendal n + a

structures passing through lesser sciatic foramen (3)

• tendon of obturator internus

• nerve to obturator internus

• internal pudendal n + a