Guide the patient to sit. With the patient relaxed and with permission, place your fingers on the dorsum of the foot and ask the patient to extend the toes (usually extension of toes 2-5 can not be performed without extending the hallux). Move your fingers to each of the long tendons to toes 2-5 while the toes alternately are extended and then relaxed. As the tendons cross the ankle area, they are covered and held in place by the superior and inferior extensor retinacula.
With the patient relaxed and with permission, place your fingers on the extensor digitorum longus muscle belly lateral to the anterior tibialis muscle belly. Guide the patient to extend the toes without dorsiflexing the ankle. With unclear muscle activity, increase the contraction of the extensor digitorum longus by asking the patient to extend the toes while you provide a push on toes 2-5 in the direction of toe flexion. Distinguish this muscle from the tibialis anterior by asking the patient to dorsiflex the ankle and observe the tibialis anterior muscle action while you maintain palpation of the extensor digitorum longus muscle belly.