Anatomy Lecture 5: Gluteal Region & Posterior Compartment of the Thigh

between iliac crest and thigh

Gluteal region

between hip and knee

(also known as lower limb or lower extremity)

Thigh region

between knee and ankle

Leg region

Two types of fascia seen in the posterior thigh

superficial fascia

fascia lata

loose connective tissue that underlies the skin and attaches it to the superficial layer of muscles (fatty)

Superficial fascia

dense, fibrous fascia covering thigh muscles

Fascia lata

The hip is known as what bone?

coxal

What bone is known as the thigh?

femur

The pelvis is made up of what?

sacrum + 2 coxal bones

The coxal bone is made up of what?

ilium

ischium

pubis

socket for femoral head

Acetabulum

What bones make up the acetabulum?

all three coxal bones (ilium, ischium, pubis)

smooth, articular surface of acetabulum

lunate surface

deep notch in the inferior part of the brim of the acetabulum

Acetabular Notch

lip of fibrocartilage that surrounds outer margin of the acetabulum on the hip bone

Acetabular labrum

continuous with acetabular labrum

spans acetabular notch

Transverse Acetabular Ligament

ligament running from the head of the femur to the acetabular notch

Ligament of the femoral head

On which part of the femur do hip fractures occur?

femoral neck

What type of joint is the hip joint?

synovial

ball and socket

What actions and ROM occur at the hip joint?

flexion/extension

abduction/adduction

lateral rotation

medial rotation

3 Ligaments of the hip joint capsule

iliofemoral ligament

pubofemoral ligament

ischiofemoral ligament

limits extension

prevents pelvis from tilting posteriorly when standing upright

Iliofemoral Ligament

limits extension

limits abduction and lateral rotation

Pubofemoral Ligament

limits extension

limits medial rotation

Ischiofemoral Ligament

As a general rule, the gluteal region is innervated by what nerve?

superior and inferior gluteal nerves

As a general rule, the posterior compartment of the thigh is innervated by what nerve?

sciatic nerve

As a general rule, the anterior compartment of the thigh is innervated by what nerve?

femoral nerve

As a general rule, the medial compartment of the thigh is innervated by what nerve?

obturator nerve

The gluteal region includes what muscles?

gluteus maximus

gluteus medius

gluteus minimus

piriformis

superior gemellus

inferior gemellus

obturator internus

quadratus femoris

The gluteus maximus is innervated by what nerve?

inferior gluteal nerve

The gluteus medius is innervated by what nerve?

superior gluteal nerve

The gluteus minimus is innervated by what nerve?

superior gluteal nerve

What is the thickest muscle in the body?

gluteus maximus

What is the origin of the gluteus maximus?

sacrum

ilium

What is the insertion of the gluteus maximus?

gluteal tuberosity (femur)

lateral condyle of tibia via iliotibial band

What is the action of the gluteus maximus?

hip extension

What muscles are deep to the gluteus maximus?

gluteus medius

gluteus minimus

piriformis

thickened fascia lata on lateral side of thigh

Iliotibial band

Gluteus medius and minimus origin

ilium

Gluteus medius and minimus insertion

greater trochanter (femur)

Gluteus medius and minimus action

hip abduction

a thin, closed sac of serous membrane

the inner surface secretes a liquid lubricant that reduces friction between adjacent structures

Bursa

between gluteus maximus and greater trochanter

Trochanteric Bursa

inflammation of the Trochanteric Bursa

may result from repetitive activity involving extension of the thigh (ex. climbing stairs while carrying a load, running on a steeply elevated treadmill)

Trochanteric Bursitis

What are symptoms of Trochanteric Bursitis?

presents as tenderness over the greater trochanter

may radiate along iliotibial band

What muscle is used as a reference structure for identifying anatomy in the deep gluteal region?

piriformis

Where does the superior gluteal nerve, artery and vein emerge?

superior to piriformis muscle

Where does the inferior gluteal nerve, artery and vein emerge?

inferior to piriformis muscle

Piriformis origin

sacrum

Piriformis insertion

greater trochanter (femur)

Piriformis action

lateral rotation of hip

The superior gluteal artery and nerve pass between what muscles?

gluteus medius and minimus

What is the blood supply of the gluteus maximus

superior and inferior gluteal arteries

What is the blood supply for the gluteus medius and minimus

superior gluteal artery

what is action 2 of the gluteus medius and minimus

stabilizes the hip during gait

explain action 2 of stabilizing the hip during gait

as one limb is lifted the contralateral hip abductor contracts

origin and insertion are reversed and muscles pull down on ilium

what does action 2 of the gluteus medius and minimus do

prevents the hip on the side of the lifted limb from dropping.

if the abductors are weakened or the superior gluteal nerve is damaged, the contralateral side of the hip sags when the limb is lifted

ex. drooping on the left side means a problem on the right side

Trendelenburg sign

opening in hip bone formed by the pubic and ischial rami

filled in with obturator membrane

Obturator Foramen

receives the weight of the body when sitting

Ischial tuberosity

What muscles are inferior to the piriformis?

superior gemellus

inferior gemellus

quadratus femoris

obturator internus tendons

What is the origin of the superior gemellus?

ischial spine

What is the insertion of the superior gemellus?

greater trochanter

What is the origin of the inferior gemellus?

ischial tuberosity

What is the insertion of the inferior gemellus?

greater trochanter

What is the origin of the quadratus femoris?

ischial tuberosity

What is the insertion of the quadratus femoris?

greater trochanter

What is the origin of the obturator internus tendons?

obturator membrane

What is the insertion of the obturator internus tendons?

greater trochanter

What is the action of the superior gemellus, inferior gemellus, quadratus femoris, and obturator internus tendons?

lateral rotation of the hip

What are the 3 muscle compartments of the thigh?

anterior

medial

posterior

supplies NO gluteal region muscles

descends to supply posterior thigh compartment muscles

Sciatic nerve

The posterior muscle compartment of the thigh is also known as

hamstrings

The sciatic nerve is composed of two divisions:

tibial division

common fibular (peroneal) division

The tibial division splits at some point (usually superior to popliteal fossa) to form this nerve

tibial nerve

Tibial nerve direction

stays in midline of lower extremity

The common fibular division splits at some point (usually superior to popliteal fossa) to form this nerve

common fibular nerve

Common fibular nerve passes in what direction

inferolaterally

The posterior compartment of the thigh (hamstrings) contains what muscles?

biceps femoris

semimembranosus

semitendinosus

What is the origin of the semitendinosus and semimembranosus

ischial tuberosity

What is the insertion of the semitendinosus and semimembranosus

medial condyle of tibia

What is the action at the hip of the semitendinosus and semimembranosus

thigh extension

What is the action at the knee of the semitendinosus and semimembranosus

leg flexion

What is the nerve supply of the semitendinosus and semimembranosus

tibial nerve (division of sciatic nerve)

Both the semitendinosus and semimembranosus insert on what side of the knee?

medial side (in contrast with biceps femoris)

The distal end of the semitendinosus is what?

long tendon

The proximal end of semimembranosus is what?

flat aponeurosis

What is the origin of the long head of the biceps femoris?

ischial tuberosity

What is the origin of the short head of the biceps femoris?

femur

What is the insertion of the long and short head of the biceps femoris?

head of fibula

What is the action at the hip of the long and short head of the biceps femoris?

thigh extension (long head only)

What is the action at the knee of the long and short head of the biceps femoris?

leg flexion

What is the nerve supply of the long head of the biceps femoris?

tibial nerve (division of sciatic nerve)

What is the nerve supply of the short head of the biceps femoris?

common fibular nerve (division of sciatic nerve)

The common origin of the posterior compartment of the thigh is

ischial tuberosity

The exception to the common origin of the posterior compartment of the thigh is

short head of biceps femoris (origin is femur)

The common insertion of the posterior compartment of the thigh is

semitendinosus & semimembranosus = medial condyle of tibia

biceps femoris = head of fibula

The common actions of the posterior compartment of the thigh is

hip extension

knee flexion

The exception to the common actions of the posterior compartment of the thigh is

short head of biceps femoris (knee flexion only)

The common nerve supply of the posterior compartment of the thigh is

tibial nerve