Week 12 Anterior & Medial Thigh - Muscles.pdf

Anterior and Medial Compartments of the Thigh Muscles of the Anterior Compartment  Sartorius o narrow, strap-shaped muscle o Origin: ASIS o Insertion: fibers run inferiorly and medially and inserts into upper part of medial surface of sh...

Anterior and Medial Compartments of the Thigh Muscles of the Anterior Compartment  Sartorius o narrow, strap-shaped muscle o Origin: ASIS o Insertion: fibers run inferiorly and medially and inserts into upper part of medial surface of shaft of tibia (part of pes anserinus together with gracilis and semitendinosus) o Nerve supply: femoral nerve o Action:  flexion, abduction and lateral rotation of thigh at hip joint  flexion and medial rotation of leg at knee joint  Pectineus o flat, quadrangular muscle o Origin: pectineal line (pecten pubis) of superior ramus of pubis o Insertion: fibers pass inferiorly and laterally and attach to posterior aspect of femur between lesser trochanter and upper end of linea aspera (pectineal line of femur) o Nerve supply: femoral nerve (occasionally, it also receives some innervation from obturator nerve) o Action: flexion and adduction of thigh at hip joint  Quadriceps Femoris o consists of 4 parts: rectus femoris, vastus medialis, vastus intermedius and vastus lateralis o Origin:   rectus femoris: straight head to AIIS; reflected head to ilium, immediately above acetabulum and rectus femoris is the only head of quadriceps femoris that originates from hip bone  vastus lateralis: upper part of intertrochanteric line, base of greater trochanter, lateral border of gluteal tuberosity and linea aspera  vastus medialis: lower part of intertrochanteric line, spiral line and linea aspera  vastus intermedius: anterior and lateral surfaces of shaft of femur o Insertion: 4 muscles pass distally and form quadriceps femoris tendon that encloses patella and distal to patella, patellar ligament is functionally the continuation of quadriceps femoris tendon and extends from lower part of patella to tibial tuberosity o Nerve supply: femoral nerve o Action:  extension of leg at knee joint (4 heads)  rectus femoris is also a flexor of thigh at hip joint  Iliopsoas o consists of iliacus and psoas major muscles (muscles of posterior abdominal wall) and pass into anterior compartment of thigh to insert into lesser trochanter of femur o Origin of psoas major: transverse processes of L1 to L5 vertebrae, intervertebral discs and adjacent parts of vertebral bodies from T12 to L5 vertebrae o Origin of iliacus: iliac fossa o Insertion: both muscles pass under inguinal ligament, in muscular space (lacuna) and insert together into lesser trochanter of femur o Nerve supply: psoas major receives direct muscular branches from ventral rami of L1-L3 spinal nerves; iliacus is innervated by femoral nerve o Action:  flexion of thigh at hip joint  acting from below (femur fixed) à flexion of trunk Muscles of the Medial Compartment  Gracilis o long and slender muscle lying superficially, along medial aspect of thigh o Origin: body and inferior ramus of pubis o Insertion: fibers run vertically down and insert into upper part of medial surface of shaft of tibia and only muscle of medial compartment that crosses knee joint (part of pes anserinus together with sartorius and semitendinosus) o Nerve supply: obturator nerve o Action:  adduction of thigh at hip joint  flexion and medial rotation of leg at knee joint  Adductor Longus o most anterior of the 3 adductor muscles o Origin: body of pubis o Insertion: fibers diverge as they pass inferiorly and laterally and insert into middle ⅓ of linea aspera o Nerve supply: obturator nerve o Action:  adduction and flexion of thigh at hip joint  Adductor Brevis o located posterior to pectineus and adductor longus o Origin: body and inferior ramus of pubis o Insertion: fibers diverge as they pass inferiorly and laterally and insert into posterior surface of femur, just lateral to pectineal line, and proximal part of linea aspera o Nerve supply: obturator nerve o Action:  action and flexion of thigh at hip joint  Adductor Magnus o largest and most posterior of adductor muscles o Origin: ischiopubic ramus and ischial tuberosity o Insertion: medial border of gluteal tuberosity, linea aspera, medial supracondylar line and adductor tubercle of femur o parts:  adductor part: consists of fibers that originate from ischiopubic ramus and insert into medial border of gluteal tuberosity, linea aspera and medial supracondylar line of femur  hamstring part: most medial part of muscle and consists of fibers vertically oriented that extend from ischial tuberosity to adductor tubercle of femur  adductor hiatus: gap in lower part of adductor magnus that communicates adductor canal with popliteal fossa and as femoral vessels pass through adductor hiatus, they become popliteal vessels o Nerve supply:  adductor part: obturator nerve  hamstring part: tibial division of sciatic nerve o Action:  adductor part: adduction of thigh at hip joint  hamstring part: extension of thigh at hip joint  adductor hiatus: gap in lower part of adductor magnus that communicates adductor canal with popliteal fossa à as femoral vessels pass through adductor hiatus, they become popliteal vessels o Nerve supply:  adductor part: obturator nerve  hamstring part: tibial division of sciatic nerve o Action:  adductor part: adduction of thigh at hip joint  hamstring part: extension of thigh at hip joint  Obturator Externus o deeply located in medial compartment o Origin: outer surface of obturator membrane and bony margins of obturator foramen o Insertion: fibers converge and pass inferior and then posterior to hip joint and insert into trochanteric fossa on medial surface of greater trochanter o Nerve supply: obturator nerve o Action: lateral rotation of thigh at hip joint Deep Fascia of the Thigh (Fascia Lata)  encloses thigh like a stocking  thickened along lateral aspect to form iliotibial tract (described in gluteal region with gluteus maximus muscle)  saphenous opening:  gap in fascia lata in superomedial part of anterior aspect of thigh  transmits great saphenous vein, small superficial branches of femoral vessels and e erent lymph vessels from superficial inguinal lymph nodes Inguinal Lymph Nodes  divided into superficial and deep groups  superficial inguinal lymph nodes:  lie in superficial fascia  horizontal group: lies just below and parallel to inguinal ligament and receives superficial lymph vessels from anterior abdominal wall (below umbilicus), perineum and gluteal region  vertical group: lies along terminal part of great saphenous vein and receives all superficial lymph vessels of lower limb (except those from lateral foot and lateral leg, which accompany small saphenous vein and drain into popliteal lymph nodes)  e erent vessels from superficial inguinal lymph nodes pass through saphenous opening and drain into deep inguinal lymph nodes Spaces Under the Inguinal Ligament  inguinal ligament: lower free margin of aponeurosis of external oblique muscle and extends from ASIS to pubic tubercle  forms boundary between abdomen and thigh  space between inguinal ligament and hip bone is divided into muscular and vascular spaces (lacunae) by a thickening of iliac fascia (interlacunar ligament or iliopectineal ligament/arch)  muscular space (lacuna): located lateral to interlacunar ligament and contains psoas major and iliacus muscles, femoral nerve and lateral cutaneous nerve of thigh  vascular space (lacuna): located medial to interlacunar ligament and contains femoral artery and vein, lymphatics and femoral branch of genitofemoral nerve