Causes of Heel Pain ("Why does my foot hurt?")

related talks: plantar fasciitis, heel bone fracture, broken ankle

Heel pain (pain in the back of the foot) is a common complaint in the general population.  It’s a condition that affects active and sedentary people alike, and it can have a variety of causes ranging from nerve impingement to microtrauma of soft tissue.  Its a common problem that poses a real challenge to many doctors.  Lets take a look at someof the most common causes to understand how they are similar and how they are different.

1) Plantar Fasciitis (see talk): This is one of the most common foot conditions, mainly occurring in people between 30 and 50 years old, but it can also occur in athletes at a younger age.  Plantar fasciitis occurs in both feet in about 1/3 of affected people.  Once believed to be an inflammatory condition of the plantar fascia, this condition is now recognized as more of a degenerative condition.  Repetitive microtrauma causes our plantar fascia to wear down and become painful.  The normal healthy tissue is replaced with disorganized collagen and calcifications that fail to provide the necessary support to your feet.  The normal function of the plantar fascia is to connect your heel bone (calcaneus) to your toes (proximal phalanges) to provide support as you push off with each step.  This is why your first step in the morning, or your first step after a long rest is sooo painful with this condition.  People report sharp pain and tenderness right where the fascia attaches to the heel bone.  X-rays are ordered to rule out other conditions which we will discuss in a moment, but this condition is diagnosed based on the history of symptoms and a doctors exam.  X-rays sometimes show a bone spur right near the plantar fascia insertion but this is actually not attributed to plantar fasciitis as it lives in a different tendon (the flexor digitorum brevis).  Treatment starts nonsurgically, with home stretching exercises, heel cushions, ice and anti-inflammatories.  Avoid walking barefoot or using shoes without support.  The goal is to stretch out the tight fascia and Achilles tendon, which together cause too much strain on the plantar fascia with each step.  A dedicated patient has a 90% chance of getting relief within 1 year.  The small number of people that keep having symptoms can consider other treatments, including steroid injections (which provide immediate pain relief but no difference in relief at 3 months compared to no injection).  Some doctors will use shock wave treatment to stimulate healing however studies aer unclear about how effective this treatment is (some say yes, others no).  Lastly surgery can be considered for those that continue to feel pain.  Most surgery involves a partial cutting of the fascia to relieve tension, and the surgery is effective in about ¾ of patients.  But remember that the more invasive a procedure, the more potential complications that can arise. 

2) Heel Pad Atrophy: As we all get older, our fat (aka adipose tissue) gets thinner.  Our heel pad is made of fat, and is an important shock absorber for daily walking.  Thus we get older our heel pad can get thinner and be less effective in protecting our foot from stresses, and this is heel pad atrophy.  People, typically over 40 years old, with this condition experience deep pain in the center of their heel, and its commonly mistaken for plantar fasciits. The location of pain and triggers of pain are different however.  X-rays and sometimes an MRI is ordered to rule out other conditions, however, this condition is usally diagnosed by a doctors exam alone.  Treatment can be a challenge, but the goal is to supplement the ineffective heel pad with good shoe padding and customized orthotics.  Steroids and surgery are not effective for this condition. 

3) Heel bone Stress Fracture: The heel bone (calcaneus) is the biggest bone in your foot and it experiences a lot of stress each day from the impact of walking and running.  Its not uncommon for this bone to become overwhelmed by this stress and develop a small crack (without any major injury causing it to occur). This is a stress fracture: the bone cannot recover from the day to day forces acting on it, and so it eventually develops a crack.  Its especially common in people that recently started a new and intense exercise routine.  People with a heel stress fracture report severe pain throughout the heel bone, which is worse when standing on the affected foot.  Its tender when squeezed.  X-rays will sometimes show the crack (usually not until 2-8 weeks after the symptoms started, because initially its just too small to see), however, overall x-rays can miss a lot of these (it misses about 90% early on, and about 50% after a few weeks), and therefore its critical to get a MRI for diagnosis.  Treatment is usually activity modification, limited weight bearing for a few weeks (4-8) and then gradual return to activities.  Overall most people heal really well.

4) Baxter nerve entrapment: Sometimes one of your foot nerves, called Baxters Nerve (a branch of the lateral plantar nerve, which is a branch of the tibial nerve) can get squished and cause burning pain along the outside of the foot.  The nerve is squished in one of two places: 1) by the Abductor Hallucis Muscle, or 2) as it passes in front of the heel bone.  Pain is felt about 5 cm from the heel at the junction between the shiny (glabrous) and nonshiny skin.  The diagnosis can be challenging, but a doctor can sometimes identify an irritated nerve by tapping over it an reproducing the symptoms of pain/burning (called a Tinel’s test).  Also decreased skin sensation around the nerve can be seen in chronic cases.  There is no “best” treatment for this condition but its usually approached first with nonsurgical techniques like shoe orthotics, anti-inflammatories and rest, then if symptoms continue for more than 3 months, doctors may consider surgical decompression, meaning, they will free up the nerve so its not compressed.  Generally results with surgery are very good, Baxter himself reported about a 90% success rate.

5) Tarsal Tunnel Syndrome: This is another type of nerve entrapment of the foot.  You can think of this as the “carpal tunnel syndrome” of the foot (because a foot is really just a smelly hand… right? Just kidding).  Remember that the Baxter nerve is a branch of the lateral planter nerve that is a branch of the Tibial nerve.  Well, Tarsal Tunnel is compression of the Tibial Nerve (so just a little bit upstream of Baxters).  Compression occurs just below your medial malleolus (aka the inside bump of your ankle).  This condition is actually very uncommon and gets over diagnosed by doctors.  Flatfeet is believe to be a risk factor for this condition because it causes the foot to bend outward (valgus, abduction) putting this area under tension.  Also the condition can be caused by a ganglion cyst (a small outpouching of the capsule, see talk) which occupies too much space in this tunnel and causes the nerve to be pinched. People with this condition complain of pain and numbness along the inner aspect of their ankle and foot (basically the opposite as Baxters).  It usually gets worse with activity, and doctors can tap on the irritated nerve (Tinels test, just like with Baxters) to recreate the pain.  Unlike Baxters however, MRI is an important part of diagnosis as well as a EMG (testing nerve stimulation of the foot muscles).  Like all of the aforementioned conditions, treatment should usually start with anti-inflammatories and orthotics.  Some doctors will consider steroid injections, if pain continues after a few weeks of treatment, however there are a number of important tendons that run near the nerve and these can be at risk for rupturing after a steroid shot, so your doctor should explain these risks before giving any steroid.  Lastly, a surgical release of the flexor retinaculum (basically opening the roof of a tunnel that’s too narrow) can be offered if all other treatments fail.  But the results of this surgery aren’t great (unlike the good results of a carpal tunnel syndrome) and only about 50% of people report good results.