Begin the last part of this exercise by identifying the most superficial plantar (sole) structure, the plantar aponeurosis . See the extent of the tough deep fascia.

When you reflect this layer you will be looking at the 1st layer of the sole of the foot.

The flexor digitorum brevis is usually attached to the deep surface of the plantar aponeurosis and the calcaneus bone. It runs to the middle phalanx of digits 2-5, like the flexor digitorum superficialis of the upper extremity.

The abductor hallucis and abductor digiti minimi are also in this 1st layer of plantar structures.

In this layer, the medial and lateral plantar nerves may be visible distally near the digits. The medial plantar nerve serves digits 1-3. while the lateral plantar nerve serves digits 4-5.

The medial plantar nerve is motor to the flexor digitorum brevis, the abductor hallucis, the flexor hallucis brevis and the 1st lumbrical.

The lateral plantar nerve is motor to the abductor digiti minimi, the quadratus plantae, flexor digiti minimi, adductor hallucis, all the interossei and the lateral 4 lumbricals.