Muscles of the Hip and Thigh: Posterior Section

3 compartments of thigh

• anterior

• posterior

• medial

fascia of the thigh structure

sleeve of CT surrounding the ms of the thigh

fascia of the thigh function (2)

• maintaining shape of the thigh

• enhancing mechanical function of the ms of the thigh

fascia of the thigh includes (2)

superficial and deep

superficial fascia is continuous with

fascia of the lower back and abdominal regions

proxima and lateral continuation of fascia is called

the iliotibial band

deep fascia aka

fascia latae

deep fascia attached anteriorly to (2)

inguinal ligament

superior pubic ramus

deep fascia attached posteriorly to (2)

• sacrum

• coccyx

deep fascia attached medially to (2)

• inferior pubic ramus

• sacrotuberous lig

deep fascia attached laterally to

form ITB

intermuscular septum

CT that extends from the deep fascia → linea aspera of femur separating one muscle from another

3 types of intermuscular septum

• lateral intermuscular septum

• medial intermuscular septum

• posterior intermuscular septum

lateral intermuscular septum location

b/w the vastus lateralis and biceps femoris muscles

medial intermuscular septum location

b/w vastus lateralis and adductor group

posterior intermuscular septum location

b/w adductor group & hamstring group

saphenous opening location (2)

• aperture located in the deep fascia

• 3cm lat to pubic tubercle

saphenous opening structure

covered by superficial fascia

saphenous opening function

allows for passage of long saphenous vein

posterior compartment - the hamstring group (3)

• bicep femoris

• semitendinosus

• semimembranosus

all of the 3 hamstring muscles have

• common origin = ischial tuberosity

• innervated by the sciatic nerve

biceps femoris intro (4)

• lateral ms

• thick cord like tendon

• tendon gives expansion for deep fascia

• short head maybe absent in some people

biceps femoris origin: long head (2)

• post-inf ischial tuberosity

• sacrotuberous lig (distal)

bicep femoris origin: short head (3)

• lat lip of linea aspera

• lat intermuscular septum

• lateral supracondylar line (prox 2/3)

biceps femoris insertion (3)

• head of fibula (lat side)

• lateral condyle of tibia

• LCL of knee

biceps femoris main actions (5)

• hip ext (long head)

• hip lat rotation (long head)

• knee flex

• knee lat rotation

• post pelvic tilt

biceps femoris innervation

sciatic nerve (L4-S3)

• long head → tibial division

• short head → common peroneal division

biceps femoris vascular supply (2)

branches off profunda femoris, medial circumflex femoral, and inferior gluteal arteries

semitendinosus intro (4)

• semi = half

• tendinous in distal portion

• passes over tibial collateral lig

• lies medial to biceps femoris

semitendinosus origin

ischial tuberosity (post-inf)

semitendinosus insertion (2)

• pes anserine

• deep fascia of leg

semitendinosus main actions (5)

• knee flex

• med rotation of knee

• hip ext

• med rotation of hip

• post pelvic tilt

semitendinosus innervation

sciatic nerve (tibial branch) L4-S3

semitendinosus vascular supply (3)

branches off:

• internal iliac

• profunda femoris

• and popliteal arteries

semimembranosus intro (2)

• membranous = upper/prox portion

• deep to semitendinosus

semimembranosus origin

ischial tuberosity (inferior)

semimembranosus insertion

medial condyle of tibia (posteromedial aspect)

semimembranosus main actions (5)

• knee flex

• med rotation of knee

• hip ext

• med rotation of the hip

• post pelvic tilt

semimembranosus innervation

sciatic nerve (tibial branch) L4-S3

semimembranosus vascular supply (3)

branches off:

• internal iliac

• profunda femoris

• and popliteal arteries