The most common form of heel pain, is pain on the bottom of the heel. It tends to occur for no apparent reason and is often worse when first placing weight on the foot. Patients often complain of pain the first thing in the morning or after getting up to stand after sitting. The pain can be a sharp, searing pain or present as a tearing feeling in the bottom of the heel. As the condition progresses there may be a throbbing pain after getting off your feet or there may be soreness that radiates up the back of the leg. Pain may also radiate into the arch of the foot.
To understand the cause of the pain one must understand the anatomy of the foot and some basic mechanics in the function of the foot. A thick ligament, called the plantar fascia, is attached into the bottom of the heel and fans out into the ball of the foot, attaching into the base of the toes. The plantar fascia is made of dense, fibrous connective tissue that will stretch very little. It acts something like a shock absorber. As the foot impacts the ground with each step, it flattens out lengthening the foot. This action pulls on the plantar fascia, which stretches slightly. When the heel comes off the ground the tension on the ligament is released. Anything that causes the foot to flatten excessively will cause the plantar fascia to stretch greater than it is accustom to doing. One consequence of this is the development of small tears where the ligament attaches into the heel bone. When these small tears occur, a very small amount of bleeding occurs and the tension of the plantar fascia on the heel bone causes a spur on the bottom of the heel to form. Pain experienced in the bottom of the heel is not produced by the presence of the spur. The pain is due to excessive tension of the plantar fascia as it tears from its attachment into the heel bone. Heel spur formation is secondary to the excessive pull of the plantar fascia where it attaches to the heel bone. Many people have heel spurs at the attachment of the plantar fascia without having any symptoms or pain. There are some less common causes of heel pain but they are relatively uncommon.
There are several factors that cause the foot to flatten and excessively stretching the plantar fascia. The primary factor is the structure of a joint complex below the ankle joint, called the subtalar joint. The movement of this joint complex causes the arch of the foot to flatten and to heighten. Flattening of the arch of the foot is termed pronation and heightening of the arch is called supination. If there is excessive pronation of the foot during walking and standing, the plantar fascia is strained. Over time, this will cause a weakening of the ligament where it attaches into the heel bone. When a person is at rest and off of their feet, the plantar fascia attempts to mend itself. Then, with the first few steps the fascia re-tears causing pain. Generally after the first few steps, the pain diminishes. This is why the heel pain tends to be worse the first few steps in the morning or after rest. Another cause of heel pain is compression of the calcaneal nerve and may be diagnosed thru neuro sensory motor testing.
One other factor that contributes to the flattening of the arch of the foot is tightness of the calf muscles. The calf muscle attaches into the foot by the achilles tendon into the back of the heel. When the calf muscle is tight it limits the movement of the ankle joint. When ankle joint motion is limited by the tightness of the calf muscle it forces the subtalar joint to pronate excessively. Excessive subtalar joint pronation can cause several different problems to occur in the foot. In this instance, it results in excessive tension of the plantar fascia. Tightness of the calf muscles can be a result of several different factors. Exercise, such as walking or jogging will cause the calf muscle to tighten. Inactivity or prolonged rest will also cause the calf muscle to tighten. Women who wear high heels and men who wear western style cowboy boots will, over time, develop tightness in the calf muscles.
The diagnosis of heel pain and heel spurs is made by a through history of the course of the condition and by physical exam. Weight bearing x-rays are useful in determining if a heel spur is present and to rule out rare causes of heel pain such as a stress fracture of the heel bone, the presence of bone tumors or evidence of soft tissue damage caused by certain connective tissue disorders.
Treatment of heel pain generally occurs in stages. At the earliest sign of heel pain, aggressive calf muscle stretching should be started. Additionally, taking an oral anti-inflammatory medication and over-the- counter arch supports or heel cushions may be beneficial.
The next phase of treatment might consist of continued calf muscle stretching exercises, cortisone injections and orthopedic taping of the foot to support the arch. If this treatment fails, or if there is reoccurrence of the heel pain, then functional foot orthotics might be considered. A functional orthotic is a device that is prescribed and fitted by your foot doctor, which fits in normal shoes like an arch support. Unlike an arch support, however the orthotic corrects abnormal pronation of the subtalar joint. Thus orthotics address the cause of the heel pain - abnormal pronation of the foot.