Anterior and Medial Thigh

Introduction

muscle function Þ three types

concentric: muscle shortens as it contracts

isometric: muscle length remains constant as it contracts

eccentric: muscle lengthens as it contracts

eccentric contraction of muscles is like a shock absorber (i.e. arch of foot, hamstrings in stopping run)
very important modality in the function of the lower limb – allows us to move without breaking bones despite the fact that we can place several times our body weight on the tiny bones of the limb when we walk, run, jump, etc

innervation of the thigh

lumbosacral plexus

lumbar portion (L1-L4)

femoral nerve (anterior division): supplies anterior compartment, and pectineus (an adductor)

obturator nerve (posterior division): supplies medial compartment (adductors except pectineus)

sacral plexus (L5-S4)

sciatic nerve: supplies hamstring muscles and part of adductor magnus; divides in popliteal fossa Þ

tibial: posterior division

peroneal (common fibular): anterior division

blood supply

external iliac – femoral: continues though the adductor hiatus as the popliteal artery
deep femoral: branch of femoral in the femoral triangle; gives rise to lateral and medial circumflex femoral

cruciate anastamosis: anastamosis with superior and inferior gluteal arteries; collateral circumflex to head of femur

evolution – many adaptations of the primate anatomy have allowed us to walk upright, and have also caused many problems:

curves in our spine are not found in any other animal Þ back pain

arches in our feet: shock absorbers for gait; big toe is no longer opposable

valgus knees: great for walking; bad for stability, easily injured

Structures in the Thigh

iliopsoas muscle combination of psoas major, psoas minor, iliacus

psoas major

origin: anterior surface of transverse process, lumbar bodies of T12-L5 and intervertebral discs

insertion: lesser trochanter of femur

innervation: 2^nd and 3^rd lumbar

artery: lumbar branch of iliolumbar

action: flexes thigh; flexes vert. column when leg is fixed

psoas minor (only in 60% of people)

origin: vertebral margins of T12, L1 and intervertebral discs

insertion: pectineal line, iliopectineal eminence

innervation: 1^st or 2^nd lumbar

artery: lumbar branch of iliolumbar

action: flexes pelvis on vertebral column; flexes vertebral column on pelvis

iliacus

origin: upper 2/3 of iliac fossa; iliac crest; anterior sacroiliac, lumbosacral, iliolumbar ligaments; ala of sacrum

insertion: tendon of psoas major, lesser trochanter, capsule of hip joint, body of femur

innervation: muscular branches of femoral

artery: iliac branch of iliolumbar, superior gluteal

action: flexes thigh; tilts pelvis forward when leg is fixed

sartorius muscle

origin: anterior superior iliac spine; upper half or iliac notch

insertion: upper part of medial surface of tibia

innervation: muscular branches of femoral

artery: muscular branches of femoral

action: flexes leg on thigh; flexes thigh on pelvis; rotates thigh laterally

quadraceps femoris: rectus femoris, vastus lateralis, vastus medialis, vastus intermedius

rectus femoris muscle

origin: straight head: anterior inferior iliac spine; reflected head: groove on upper rim of acetabulum

insertion: upper border of patella; by ligamentum patellae into tibial tuberosity

innervation: muscular branches of femoral

artery: lateral femoral circumflex

action: extends leg; flexes thigh

vastus lateralis muscle

origin: capsule of hip joint, intertrochanteric line, greater trochanter, gluteal tuberosity, linea aspera, lateral intermuscular septum

insertion: lateral border by patella, by ligamentum patellae into tibial tuberosity

innervation: muscular branches of femoral

artery: lateral femoral circumflex, lat. superior genicular

action: extends leg

vastus medialis muscle

origin: lower half of intertrochanteric line, linea aspera medial supracondylar line, medial intermuscular septum, tendon of adductor magnus

insertion: quadriceps femoris tendon, medial border of patella, capsule of knee joint, by ligamentum patellae into tibial tuberosity

innervation: muscular branches of femoral

artery: muscular branches of femoral, profunda femoris

action: extends leg and draws patella medially

vastus intermedius muscle

origin: upper 2/3 of anterior and lateral surface of femur, lower half of linea aspera, upper part of lateral supracondylar line, lateral intermuscular septum

insertion: deep surface of tendons of rectus and vasti muscles, by ligamentum patellae into tibial tuberosity

innervation: muscluar branches of femoral

artery: lateral femoral circumflex

action: extends leg

gracilis muscle

origin: lower half of pubic symphysis, upper half of pubic arch

insertion: upper part of meidal sirface of tibia

innervation: anterior branch of obturator

artery: muscular branches of profunda femoris, obturator, medial femoral circumflex

action: flexes leg; medially rotates at hip joint; adducts thigh

pectineus muscle

origin: pectineal line, surface of pubis between iliopectineal eminence and pubic tubercle

insertion: line extending from lesser trochanter to linea aspera

innervation: muscular branches of femoral

artery: medial femoral circumflex, obturator

action: adducts, flexes, medially rotates thigh

adductor longus muscle

origin: front of pubis in angle between crest and symphysis

insertion: middle half of medial lip of linea aspera

innervation: anterior branch of obturator

artery: medial femoral circumflex, obturator

action: adducts thigh; assists in flexion

adductor brevis muscle

origin: outer surface of inferior ramus of pubis

insertion: line extending from lesser trochanter to linea aspera

innervation: anterior branch of obturator

artery: medial femoral circumflex, obturator

action: adducts thigh; assists in flexion

adductor magnus muscle

origin: ischial tuberosity, rami of ischium and pubis

insertion: line extending from greater trochanter to linea aspera, linea aspera, medial supracondylar line, adductor tubercle

innervation: posterior branch of obturator, sciatic

artery: medial femoral circumflex, profunda femoris, obturator, branches of popliteal

action: adducts thigh; upper portion flexes is; lower portion extends it

tensor fascia latae muscle

origin: anterior part of outer lip of iliac crest, anterior border of ilium

insertion: middle third of thigh along iliotibial tract

innervation: superior gluteal

artery: lateral femoral circumflex, superior gluteal

action: tenses fascia lata (counteracts pull of glut max on iliotibial tract; aids in abducting, medially rotating thigh

articularis genum (may be blended with vastus intermedius)

origin: anterior inferior aspect of femur

insertion: synovial capsule of knee

action: pulls synovial capsule anteriorly during extension to keep it from getting caught in the joint

innervation: femoral

inguinal ligament: ligament runs from anterior superior iliac spine to pubic tubercle; superior border of femoral triangle

adductor (Hunter’s) canal: fascial tunnel running deep to the middle third of the sartorius boundries: anterior: sartorius; posteromedial: adductor longus/magnus; lateral: vastus medialis

femoral ring: superior mouth of the femoral canal

adductor hiatus: tendinous opening in adductor magnus where femoral a and v leave the adductor canal

adductor tubercle: small prominence at superior medial epicondyle of femur; insertion of adductor magnus

fascia lata: deep fascia of the thigh; surrounds entire thigh in a tube; increases efficiency of muscles by preventing excessive bulging

saphenous opening: hole in the fascia lata just inferior to inguinal ligament; great saphenous vein passes though just before it joins with the femoral artery

iliotibial band: thickened lateral component of fascia lata; runs from iliac crest to lateral condyle of tibia; pulled on by the tensor fascia latae muscle to stabilize the trunk on the thigh

ligamentum patellae: continuation of the quadriceps tendon; attaches patella to the tibial tuberosity

femoral sheath and compartments: fascial tube (~ 4 cm); encloses femoral vessels (artery, vein, lymph, NO nerve) inferior to inguinal ligament; fascia is continuous with transversalis and iliac fasciae; allows vessels to slide easily with movement of thigh; femoral hernia risk (greater in females due to wider hips)

femoral canal: medial compartment of the femoral sheath; contains some lymph nodes and vessels; allows for venous expansion

femoral triangle: contains femoral vessels and nerves (lateral Þ medial - NAVEL: nerve; artery; vein; empty; lymphatic)

boundries: superior: inguinal ligament; medial: adductor longus; lateral: sartorius; floor: pectineus, iliopsoas

intermuscular septae: divide the muscles of the thigh into three fascial compartments: anterior, posterior, medial

great saphenous vein: begins at medial end of dorsal venous arch of foot; passes anterior to the medial maleous of the tibia; runs obliquely superficial to the medial epicondyle; runs though saphenous opening to join with the femoral vein; longest vein in the body; often used for venous grafts (highly anastomotic, so you can afford to lose it); also a great place to start an IV if other veins have collapsed (i.e. shock)

femoral vena profunda (deep femoral vein): runs with profunda femoris artery

femoral artery continuation of external iliac; runs along the adductor canal

profunda femoris artery branch of femoral about 4 cm inferior to the inguinal ligament; main artery to thigh; runs deep to the

lateral femoral circumflex artery branch of profunda femoris (but highly variable); supplies lateral thigh and head of femur

medial femoral circumflex artery branch of profunda femoris (but highly variable); main blood supply for the head and neck of the femur; passes between the iliopsoas and pectineous muscles

femoral nerve largest branch of sacral plexus (from posterior branches of L2-L4); runs lateral to femoral vessels (outside femoral sheath) supplies anterior thigh

saphenous nerve cutaneous branch of femoral n; runs along adductor canal; becomes superficial as it passes between the sartorius and graciluis muscles; supplies anterior aspects of knee, leg, foot

lateral femoral cutaneous nerve from posterior branches of L2-L3; supplies skin on anterior and lateral thigh

medial femoral cutaneous nerve

genitofemoral nerve branches: from L1-L2; supply skin just inferior to the middle part of the inguinal ligament

ilioinguinal nerve from L1; supplies superomedial skin of thigh via anterior scrotal/labial branch

cutaneous branch of obturator nerve from anterior division of L2-L4; supplies skin on middle third of medial thigh

intermediate femoral cutaneous nerves supply skin on anterior thigh

linea aspera obturator nerve