MUSCLES-ANTERIOR COMPARTMENT OF LEG

SUMMARY

1. TIBIALIS ANTERIOR - arises from the upper 2/3 of the extensor surface of the tibia + anterior interosseous membrane + overlying deep fascia. Its tendon pierces the superior extensor retinaculum (where it is enclosed by a synovial sheath) + inferior extensor retinaculum to be inserted into the medial cuniform.
ALL TENDONS PASS BENEATH THE LATERAL SUPERIOR + INFERIOR EXTENSOR RETINACULUM


2. EXTENSOR HALLUCIS LONGUS - arises from the middle of the fibula + anterior interosseous membrane. Its tendon passes beneath the superior extensor retinaculum (where it is enclosed by a synovial sheath) + inferior extensor retinaculum to be inserted into the terminal phalanx of the great toe.

3. EXTENSOR DIGITORUM LONGUS - arises from the upper 3/4 of the extensor surface of the fibula + tib/fib joint + anterior intermuscular septum + overlying deep fascia. It forms 4 tendons which pass beneath the superior extensor retinaculum + inferior extensor retinaculum (where it shares a synovial sheath with the peroneus tertius tendon) to be inserted into the lateral 4 toes. 

4. PERONEUS TERTIUS - arises from the lower 1/3 of the fibula beneath the EDL + EHL. Its tendon passes beneath the superior extensor retinaculum + inferior extensor retinaculum (where it shares a synovial sheath with the EDL tendons) to be inserted into the dorsum of the base of the 5th metatarsal.

5. Nerve supply - all are supplied by the deep peroneal nerve. 

6. Arterial supply - branches of the anterior tibial artery. 

Reference(s)

R.M.H McMinn (1998). Last’s anatomy: regional and applied. Edinburgh: Churchill Livingstone.
Gray, H., Carter, H.V. and Davidson, G. (2017). Gray’s anatomy. London: Arcturus.