Now we’ll look at the nerves of the foot. We’ll follow the nerves that we saw in the last section: the superficial and deep peroneal nerves, and the medial and lateral plantar nerves. There are two more nerves that we’ll also look at for completeness - the sural nerve, and the saphenous nerve. We’ll start with the two peroneal nerves.
The superficial peroneal nerve runs down in front of the lateral side of the ankle, and breaks up into several branches. These fan out to provide sensation to this large area on the dorsum of the foot.
The deep peroneal nerve enters the foot along with the dorsalis pedis artery. It gives off a motor branch, which supplies the short toe extensor muscles. It continues distally as a sensory nerve, which supplies this small area between the big and second toes.
Next we’ll look at the medial and lateral plantar nerves. They follow the same course as the medial and lateral plantar arteries. Here’s the medial plantar nerve. It gives off motor branches which supply flexor digitorum brevis, abductor hallucis, and flexor hallucis brevis.
To follow the medial plantar nerve, we’ll go round to the underside of the foot. Distally, the medial plantar nerve breaks up into common plantar digital nerves. These pass between the metatarsal heads, where each in turn divides into two plantar digital nerves.
The median plantar nerve supplies the underside of the big toe, the second, third and half of the fourth toes. It also supplies this medial area on the sole of the foot
Now we’ll look at the lateral plantar nerve. It runs just in front of the lateral plantar artery. To follow it, we'll again go round to the underside of the foot. Flexor digitorum brevis has been removed. The lateral plantar nerve gives motor branches to flexor accessorius and abductor digiti minimi.
It then divides into a deep branch, which suppies all the interossei and adductor hallucis, and a superficial branch, which supplies flexor digiti minimi brevis, and provides sensation to the lateral part of the sole, the fifth toe and half of the fourth toe
To complete our picture of the nerves that provide sensation to the foot, we’ll add two nerves that were passed over in the last section - the sural nerve, and the saphenous nerve.
The sural nerve, which runs down the back of the leg, is formed by two nerves which join together. One is the medial sural cutaneous branch of the tibial nerve, the other is the sural communicating branch of the common peroneal nerve.
The sural nerve runs down the lateral side of the ankle, behind the lateral malleolus. The sural nerve supplies sensation to a variable area along the lateral side of the foot.
The saphenous nerve, a branch of the femoral nerve, emerges at the knee, from beneath the insertion of the sartorius muscle. It runs down the medial side of the leg, and supplies a variable area on the medial side of the foot and ankle.
Last of all, the heel area is supplied by calcaneal branches of the tibial nerve, which are given off beneath the flexor retinaculum.