An understanding of the formation of heel spurs is closely linked to the causation of the related inflammatory condition of the foot, plantar fasciitis. The heel bone, known as the calcaneus, is the largest bone in the foot. It is subject to significant forces with every stride, or at every occasion when the foot is required to bear body weight. The plantar fascia is the long fibrous tissue that supports the arch of the foot, anchored at one end on the surface of the heel, and connected at the other end to the ball of the foot, or forefoot.
Plantar fasciitis is an irritation of the plantar tissue; the specific site of discomfort can be anywhere along the tissue band. Small calcium deposits, appearing as a thin bony growth in an x-ray, will sometimes form on the outer edge of the heel bone. These are heel spurs, which occur in widths that range from 0.1 in 0.3 in (1 mm to 5 mm). In approximately 70% of all plantar fasciitis cases, heel spur formation occurs, but the two conditions are not necessarily dependant on one another.
The plantar fasciitis condition is believed to be the primary cause of pain in the foot; the bony heel spur is a structural abnormality. The pain is produced as a result of the irritation, similar to tendonitis, caused to the plantar tissue. These combined conditions are common in persons over the age of 45 years, due to accumulated stresses generated on the foot; athletes in sports such as distance running are most susceptible to the onset of plantar fasciitis.
There are a number of factors that often contribute to the combined development of plantar fasciitis and heel spurs. Imbalances in the relationship between the calf muscles, Achilles tendon, and the muscles of the foot are the most prominent contributors. When the calf muscles are tight as a result of not being properly stretched, the plantar structure is overstretched and it becomes irritated. When an athlete uses footwear that is not sufficiently supportive, particularly in the shoe construction that contacts the heel, known as the heel counter, the junction between the heel bone and the plantar may be unnaturally stressed.
The combined effect of heel spurs and plantar fasciitis will never present a life-threatening condition to an athlete or a sedentary person. The conditions are most noticeable when the person is first mobile in the morning, and it tends to lessen as the foot and the plantar tissue are stretched by normal movement as the day progresses. The result of these conditions on both performance and day-to-day comfort can be dramatic. It is virtually impossible for an athlete in a running sport to perform to an optimal level if foot pain is experienced throughout all training and competitive sessions. There are numerous remedies that may be utilized in the treatment of a heel spur or plantar fasciitis condition. The least invasive approaches, useful in the short to medium term, include: rest; stretching programs for both the foot and specific plantar tissues, as well as the calf muscles and the Achilles tendon, to achieve a better balance between those structures; the application of ice to the entire bottom of the foot after all sports activity; anti-inflammatory medications; taping the foot for additional support during training or competition; an orthotic to correct misalignment in the strike of the foot; and shoes with proper fit and additional cushioning and support in the heel.
In the longer term, when the less invasive strategies have not succeeded in countering the effects of these conditions, some athletes have obtained relief through cortisone injections. Cortisone, as a powerful synthetic anti-inflammatory, is a prescription medication that must be carefully weighed as an option due to the pronounced risks generally associated with this type of glucocorticoid injection in a small structure such as the heel (risk of rupture of the plantar).
Surgery is almost always a final resort. In this procedure, the goal is to loosen the tight, inflamed plantar tissue through a procedure known as a release. Such procedures are not always successful; if the plantar is made too lax, the person may become flat footed, or in some cases the delicate nerve pathways of the foot may be damaged. A procedure that has received greater prominence in recent years is a non-invasive extracorporeal shock wave therapy (ESWT), in which waves are directed to the affected tissue, to stimulate a micro-tear of the plantar fiber, an event that is believed to stimulate healthy plantar growth.