Extensor Digitorum Longus - of the anterior lower leg

Last week we discussed brevis and today it's Extensor Digitorum Longus

Extensor: performs the muscle action of "extension" (of the...
Digitorum: digits - in this case the digits of the foot (aka toes)
Longus: has a similar 'sister muscle' but is the longer of the two

NOT to be confused with Extensor Digitorum of the wrist :)

Extensor Digitorum LONGUS Muscle Attachments:

Origin: 

-Lateral tibial condyle, (the outside edge of the tibia (knee end aka proximal) right next to the fibula)
 -the proximal 2/3 of the tibia
-and the proximal 2/3 of the interosseus membrane)

Insertion: toes 2-5 ! (all the toes except for the big toe - #1)

Extensor Digitorum LONGUS Muscle ACTIONS:

a) dorsiflexion of the foot at the ankle joint (toes pointing UP as opposed to down, towards the floor)

b) extension of toes 2-5 at the MTP, PIP, & DIP joints*

extending the toes means to lift them - so if you were standing, toes would aim towards the sky :)

*MTP: Metatarsal-phalangeal joint

*PI : proximal inter-phalangeal joint

*DIP: distal interphalangeal joint



See you next week! Tibialis Anterior :)