Actions, origins, insertions, innervations of leg muscles

Gluteus maximus origin

dorsal ilium, sacrum, and cocyx

Gluteus maximus insertion

gluteal tuberosity of femur; iliotibial tract

gluteous maximus action

major thigh extensor, laterally rotayes and abducts thigh

gluteous maximus innervation

inferior gluteal nerve (L5, S1, S2)

tensor fasciae latae origin

anterior aspect of iliac crest and anterior superior iliac spine

tensor fascia latae insertion

iliotibial tract

tensor fascia latae action

steadies leg and trunk on thigh by tightening iliotibial tract, flexes, abducts, and medially rotates thigh

tensor fascia latae innervation

superior gluteal nerve (L4 and L5)

Gracilis origin

inferior ramus and body of pubis and adjacent ischial ramus

gracilis insertion

medial surface of tibia just inferiror to its medial condyle

gracilis action

adducts thigh, flexes and medially rotates leg

gracilis innervation

obturator nerve

iliacus origin

iliac fossa and creast, ala of sacrum

iliacus insertion

lesser trochanter of femur via iliopsoas tendon

iliacus action

prime mover for flexing thigh or flexing trunk on thigh

iliacus innervation

femoral nerve (L2 and L3)

Psoas major origin

transverse proceses, bodies, and discs of lumbar vertebrae and T12

psoas major insertion

lesser trochanter of femur via iliopsoas tendon

psoas major action

flexes thigh and vertebral column

psoas innervation

ventral rami (L1-L3)

biceps femoris long head origin

ischial tuberosity

biceps femoris short head origin

linea aspera, lateral supracondular line, and distal femur

biceps femoris insertion

into head of fibula and lateral condyle of tibia

biceps femoris action

extends thigh and flexes leg, laterally rotates leg

biceps femoris innervation

sciatic nerve- tibial nerve to long head, common fibular nerve to short head (L5-S2)

rectus femoris origin

anterior inferior iliac spine and superior margin of acetabulum

rectus femoris insertion

patella and tibial tuberosity via patellar ligament

rectus femoris action

extends leg and flexes thigh at hip

rectus femoris innervation

femoral nerve

popliteus origin

lateral condyle of femur and lateral meniscus of the knee

popliteus insertion

proximal tibia

popliteus action

flexes and rotates leg medially to unlock extended knee when flexion begins

popliteus innervation

tibial nerve (L4-S1)

tibialis anterior origin

lateral condyle and upper 2/3 of tibial shaft; interosseous membrane

Tibialis anterior insertion

medial cuneiform and first metatarsal bone

tibialis anterior action

prime mover of dorsiflexion, inverts foot

tibialis anterior innervation

deep fibular nerve (L4 and L5)

gastrocnemius origin

2 heads from medial and lateral condyles of femur

gastrocnemius insertion

posterior calcaneous via calcaneal tendon

gastrocnemius action

plantar flexes foot when leg is extended

gastrocnemius innervation

tibial nerve (S1-S2)

flexor digitorium longus origin

posterior tibia

flexor digitorium longus insertion

into distal phalanges of 2nd to 5th phalanges of 2nd to 5th toes

flexor digitorium longus action

plantar flexes and inverts foot; flexes toes

flexor digitorium longus innervation

tibial nerve (L5-S2)

flexor hallicus longus origin

midshaft of fibula';interosseous membraine

flexor hallicus longus insertion

distal phalanx of great toe

flexor hallicus longus action

plantar flexes and inverts foot; flexes great toe at all joints

flexor hallicus longus innervation

tibial nerve (L5-S2)

Extensor digitorium longus origin

lateral condule of tibia; proximal ¾ of fibula; interosseous membrane

extensor digitorium longus insertion

middle and distal phalanges of 2nd to 5th toes

extensor digitorium longus action

prime mover of toe extension

extensor digitorium longus innervation

deep fibular nerve (L5 and S1)

extensor hallicus longus origin

anteromedial fibular shaft and interosseous membrane

extensor hallicus longus insertion

distal phalanx of great toe

extensor hallicus longus action

extends great toe

extensor hallicus longus innervation

deep fibular nerve (l5 and S1)

flexor hallicus brevis origin

lateral cuneiform and cuboid bones

flexor hallicus brevis insertion

base of proximal phalanx of great toe

flexor hallicus brevis action

flexes great toe at metatarsophalangeal joint

flexor hallicus brevis innervation

medial plantar nerve

extensor digitorium brevis origin

anterior part of calcaneous bone

extensor digitorium insertion

base of proximal phalanx of great toe

extensor digitorium brevis action

helps extend toes at metatarsophalangeal joint

extensor digitorium brevis innervation

deep fibular nerve (L5 and S1)