Lower Extremity Muscles

This set of flashcards covers key muscles of the lower extremity, including origin, insertion, and primary functions.

Piriformis

Originates from the anterior surface of the sacrum and inserts at the superior greater trochanter. Function: External Rotation.

Quadratus Femoris

Originates from the lateral ischial tuberosity and inserts at the intertrochanteric crest between greater and lesser tubercule. Function: External Rotation.

Gluteus Maximus

Originates from the coccyx, edge of sacrum, and posterior iliac crest; inserts at the iliotibial tract and gluteal tuberosity. Function: Extension and External Rotation.

Gluteus Medius

Originates from the gluteal surface of ilium between anterior/posterior gluteal lines below iliac crest; inserts at the lateral greater trochanter. Function: Abduction.

Gluteus Minimus

O-glut surface of ilium btw ant and inf

glut lines

I-Ant greater trochanter

ABD

Psoas Major

O-bodies of transverse processes of lumbar vert

I-lesser trochanter

Flex hip and trunk

Iliacus

O-Iliac fossa

I-lesser trochanter

Flex hip and trunk

Tensor Fasciae Latae

O-Iliac crest, post to ASIS

I-Iliotibial tract

ABD, flex, IR

Rectus Femoris

Part of the quadriceps group, originates from the anterior inferior iliac spine (AIIS) and inserts at the superior patella and tibial tuberosity. Function: Hip flexion and knee extension.

Vastus Medialis

O-whole linea aspera and medial condyloid ridge

I-medial border patella to tibial tuberosity

Knee ext

Vastus Lateralis

O-Intertrochanteric line, ant and inf greater trochanter, gluteal tuberosity, upper half of linea aspera, entire lateral intermuscular septum

I - Tibial tuberosity (via the patella and patellar ligament)

Knee ext

Sartorius

O-ASIS

I-pes anserine

Hip flex, ER, ABD Knee flex

Biceps Femoris

O - Ischial tuberosity

I - Head of fibula

Flex the knee, extend the hip

Semitendinous

O - Ischial tuberosity

I - Pes anserine

Flex the knee, extend the hip

Semimembranous

O - Ischial tuberosity

I - Posterior medial condyle

Flex the knee, extend the hip

Gracilis

O-inf ramus of pubis

I-pes anserine

Hip ADD, some flex, IR Knee flex, IR

Adductor longus

O-Pubic tubercle

I-medial lip of linea aspera

ADD, IR, flex

Adductor Magnus

O-inf ramus of pubis, ramus of ischium,

ischial tuberosity

I-medial lip of linea apsera and adductor tubercle

ADD, IR, flex

Tibialis Anterior

O-lateral condyle of tibia, proximal and

lateral tibia, interosseous membrane

I-Medial cuneiform and base of 1st

metacarpal (dorsal)

Ankle dorsiflexor and inverter

Extensor Digitorum Longus

O-lateral condyle of tibia, proximal and

anterior shaft of fibula and interoseous

membrane

I-middle and distal phalanges of 2-5

toes

DF, EV, extend dig

Extensor Hallucis Longus

O-middle, anerior surface of fibula and interosseous membrace

I-distal phalanx of great toe

DF, INV, ext hall

Peroneus Longus

O-head of fibula and proximal 2/3 of lateral fibula

I-base of 1st metatarsal and medial cuneiform (plantar)

Plantarflexor and everter of the ankle

Peroneus Brevis

O-distal 2/3 of lateral fibula

I-tuberosity of 5th metatarsal

PF, EV

Gastrocnemius

O-Posterior Condyles of femur

I-Calcaneus, tuberosity

plantarflexes the ankle

Soleus

O-Proximal posterior surface of tibia and posterior head of fibula

I-Calcaneus tuberosity

PF

Plantaris

O-lateral supercondylar line of femur

I-Calcaneus (medial)

PF

Tibialis Posterior

O-Proximal posterior tibia and fibula and interosseus membrane

I- All tarsal bones and bases 2-4 metatarsals

PF, INV

Flexor Digitorum Longus

O-middle posterior tibia

I-distal phalanges of 2-5 toes

PF, INV, flex dig

Flexor Hallucis Longus

Plantarflexor and inverter, originates from the middle half of the posterior fibula, inserting at the distal phalanx of the great toe.

Abductor Hallucis

O-medial process of calcaneus and

plantar aponeurosis

I-proximal phalanx of Great toe and

medial Sesamoid bone (plantar)

Muscle responsible for the abduction of the great toe