Key actions of the anterior and lateral compartment muscles:
- Dorsiflexion
- pull the dorsal surface (aka, top) of your foot towards the anterior leg to demonstrate this action.
- Plantar flexion
- push the ventral surface (aka, sole) of your foot towards the posterior leg to demonstrate this action.
- Eversion
- turn the ventral surface of your foot to face laterally to demonstrate this action.
- Inversion
- turn the ventral surface of your foot to face medially (towards the midline of the body) to demonstrate this action.
Anterior compartment leg muscles:
Fibularis tertius
- Originates on distal fibula and interosseous membrane
- Inserts on the base of the 5th metatarsal;
- Dorsiflexes and everts the foot.
Extensor digitorum longus
- Originates on the lateral tibial condyle, the interosseous membrane, and, the proximal 2/3rds of the fibula
- Inserts on the bases of the middle and distal phalanges of digits 2-5
- Extends the toes and dorsiflexes and everts the foot.
Extensor hallucis longus
- Originates on the middle of the anterior fibula and interosseous membrane
- Inserts on the base of the distal phalanx of digit 1
- Extends the big toe and dorsiflexes and inverts the foot.
Tibialis anterior
- Originates on the lateral tibial condyle and the interosseous membrane
- Inserts on the first cuneiform and first metatarsal
- Dorsiflexes and inverts the foot.