Tibialis anterior, Extensor hallucis longus, Extensor digitorum longus and Fibularis tertius, supplied by the deep fibular nerve
Mnemonic
“Tibialis anterior, Extensor hallucis longus, Extensor digitorum longus, fibularis tertius”, all supplied by the deep fibular nerve and all dorsiflexors.
The deep fibular nerve is the “D” nerve: Deep fibular, Dorsiflexion, Dorsal web space sensation between the first and second toes.
Injury gives foot drop with a high stepping gait, and the sensory loss is confined to the small web space, which distinguishes it from a common fibular lesion, where sensation over the whole dorsum and lateral leg is lost.
Expansion
- Tibialis anterior
- Extensor hallucis longus
- Extensor digitorum longus
- Fibularis (peroneus) tertius
All are supplied by the deep fibular nerve and dorsiflex the ankle, with tibialis anterior also inverting the foot. This compartment is the commonest site of acute compartment syndrome in the leg.