Pain in the heel can be caused by dysfunction or compression of a nerve. One more well-known nerve compression is tarsal tunnel syndrome. Tarsal tunnel syndrome (the foot version of carpal tunnel) is caused by compression of the nerve that lies behind the ankle on the inside aspect. This particular nerve is called the posterior tibial nerve. The area behind the ankle is tight for space and this area is shared between 3 tendons, the posterior tibial nerve, and an artery with accompanying veins. The tarsal tunnel is called a tunnel because overlying these structures is a band of fascia that keeps them from moving out of place.
What can happen within this tarsal tunnel is that one or a couple anatomical structures in this area can become inflammed and this makes the small space even tighter. When pressure is put on a nerve, it can produce sensations of tingling, burning and pain. This is the hallmark of tarsal tunnel syndrome.
Nerves in the body are like branches and twigs on a tree. A large tree trunk has many branches and off of those branches there are smaller branches and so on. Nerves originate from the spinal cord and brain (the trunk of the tree) and diverge into many branches that supply sensation and muscular innervation throughout the body. Because the posterior tibial nerve is a branch of a nerve that originates in the back, pain or compression of the nerve in the back can actually cause pain and symptoms in the ankle or foot.
Similarly, there are branches off of the posterior tibial nerve that provide sensation to various parts of the foot. One such branch is referred to as "Baxter's nerve." The technical term for this nerve is inferior calcaneal nerve. This nerve branches off of the tibial nerve and then directs down to the bottom of the heel. This nerve can be aggravated as a result of tarsal tunnel or as a result of being impinged within the muscular tissue and ligaments that are in this area of the foot.
Baxter's neuritis presents as heel pain in the bottom of the heel that typically gets worse with activity. Some aspects of treatment are similar to those of plantar fasciitis, but there are some special considerations with Baxter's neuritis. It is yet another condition that is considered in situations where heel pain does not respond to traditional treatments for plantar fasciitis, or if the symptoms that develop are more nerve-related pain.
As with any other conditions causing heel pain, the only way to truly know the underlying cause is to undergo a thorough physical exam by your local foot care specialist! Come in and see us if your heel hurts!