Tibialis Anterior - of the anterior lower leg

Tibialis Anterior is one of the well known lower leg muscles, maybe because it's

pretty obvious on most people :)

Tibialis: referring to the lower leg bone that the muscle runs along.

Anterior: lives on the front (aka "anterior") of the lower leg.

me activating Tibialis Anterior - it's muscle belly is right

under my finger see?

Tibialis Anterior Muscle Attachment Points

Origin:  lateral tibial condyle & the proximal 2/3 of the tibia* AND the proximal 2/3 of the interosseus membrane (see pic below) 

*the outside edge of the tibia (knee end aka proximal) right next to the fibula)

Insertion:  1st cuneiform & the first metatarsal

((aka just under the right side of your knee, travels down the tibia bone crossing at the front of the ankle, with its tendon inserting on the inside arch of your foot))

Tibialis Anterior Muscle Actions

a) dorsiflexion of the foot at the ankle joint

aka toes pointing up to the sky (& heel down towards ground)

do this 25x and feel your Tibialis Anterior BURN ;)

b) inversion of the foot at the @ the sub-talar joint:

'turning your ankle inwards'

Maintaining ankle range of motion, strength and balance between the muscles all around is so so important  - so important that I made a video about it enjoy ! :

Fibularis Tertius - of the lower leg

Yes! Another Fibularis muscle! Fibularis referring to the fibula bone the muscles attach to.

Fibularis Tertius lives in anterior compartment of the lower leg (the front of the body) whereas Fibularis Longus and Brevis live in the lateral compartment.

Fibularis Tertius Muscle Attachments

ORIGIN: distal 1/3 of the anterior fibula and the distal 1/3 of the interosseous membrane

INSERTION:  dorsal surface of the base of the 5th metatarsal

Fibularis Tertius is actually an extension of Extensor Digitorum longus ( a muscle we haven't covered yet!) - also of course in the anterior compartment of the lower leg/ankle.  In fact, Fibularis Tertius may not even be present in some folk!

Fibularis Tertius Muscle Actions

a) DORSI-FLEXION of the foot at the ankle joint

Dorsiflexion is when your bring your foot UP (heel down -toes up)

Dorsi refers to the dorsal surface of your foot (aka the the top of you foot).

b) EVERSION of the foot at the sub-talar joint

TERTIUS comes from the latin word meaning "third" - because this muscle is the third 'fibularis' (aka Peronneal) muscle.

But when I hear Tertius all I can think about is.....