Thigh Muscles

what are the three regions of the thigh

anterior(extenders), posterior(hamstrings), and medial (adductors)

sartorious (anterior)

origin: anterior superior iliac spine (ASIS)

insertion: upper part of medial surface of tibial shaft

action: flexes, abducts, externally rotates thigh, internally rotates leg at knee when flexed

innervation: femoral nerve

rectus femoris (anterior)

origin: Anterior Inferior iliac spine (AIIS)

insertion: tibial tuberosity via patellar tendon

action: flexes thigh, extends lower leg (knee)

innervation: femoral nerve

vastus lateralis (anterior)

origin: intertrochanteric line of femur

insertion: tibial tuberosity via patellar tendon

action: extends lower leg at knee

innervation: femoral nerve

vastus medialis (anterior)

origin: intertrochanteric line of femur

insertion: tibial tuberosity via patellar tendon

action: extends lower leg at knee

innervation: femoral nerve

vastus intermedius (anterior, deep)

origin: anterior and lateral 2/3 of femur

insertion: tibial tuberosity via patellar tendon

action: extends lower leg (knee)

innervation: femoral nerve

Gracilis (medial, adductor)

origin: pubic ramus

insertion: upper medial shaft of tibia

action: adducts thigh

innervation: obturator nerve

Pectineus (medial)

origin: superior ramus of pubis

insertion: lesser trochanter of femur

action: flexes thigh, assist with adduction when hip is flexed

innervation: femoral nerve

adductor longus (medial)

origin: anterior pubis

insertion: linea aspera on posterior aspect of femur

action: adducts thigh, assists with medial rotation

innervation: obturator nerve

adductor brevis (medial)

origin: inferior ramus of pubis

insertion: linea aspera of femur

action: adducts thigh

innervation: obturator nerve

adductor magnus (medial)

origin: inferior ramus of pubis

insertion: linea aspera and adductor tubercle of femur

action: adducts and extends thigh at hip

innervation: obturator nerve

biceps femoris (posterior)

origin: long head: ischial tuberosity; short head: linea aspera of femur

insertion: head of fibula

action: flexes knee, long head also extends thigh

innervation: long head: tibial nerve; short head: common peroneal nerve

Semitendinosus (posterior)

origin: ischial tuberosity

insertion: medial superior tibia

action: flexes knee and extends thigh

innervation: tibial nerve

semimembranosus (posterior)

origin: ischial tuberosity

insertion: posterior superior tibia

action: flexes knee and extends thigh

innervation: tibial nerve