Foot Pain

Written by staff | 13 July 2011

The foot is the basis of human locomotion, providing movement, shock absorption and balance. With time, most people clock a great deal of time on their feet, and about 75% of people in the US experience foot pain at some time. In fact, according to a 2009 American Podiatric Medical Association (APMA) survey, nearly 40% of Americans experience foot pain that is so severe, it impairs day-to-day life—and this pain should never be ignored¹.

Ill-fitting or complicated shoes such as high heels take their toll on feet, as does wear and tear from sports and aging. Pain in the foot can be a sign that internal or external components of the foot have sustained damage. Damage to the foot can occur from mechanical injury or from disease processes.

The foot is a complex structure comprised of muscles tendons, ligaments, and bones. The chief support structure of the foot is the 28 bones and more than 30 joints². The muscles of the foot, along with tough, sinewy tissue called fascia, also provide support to the foot. Ligaments connect bones in the foot to other bones, and tendons connect muscles of the foot to bones. Fat pads in the foot join the ligaments in bearing weight and absorbing impact.

During a lifetime, the physical components of the foot sustain an unfathomable amount of physical use and abuse, which is why mechanical injury is the most common reason for foot pain.

Since feet are very small relative to body, they carry a tremendous amount of weight and disperse a great deal of force. Although feet are built for a lifetime of service, sudden injury or gradual wear and tear can harm the feet.

Mechanical injuries such as sprains and strains are commonly the result of acute (sudden) trauma to the foot. Sprains refer to stretching or tearing of the ligaments. In particular, ligaments on the soles of the foot bear a great deal of weight and can sprain when subjected to excessive stress. The sister ailment to sprains is strains, or stretching or tearing of tendons. Like ligaments, tendons are subjected to constant stress and are prone to injury. Another common problem often seen in tendons in the foot is tendonitis, or inflammation and irritation of the tendon due to mechanical stress. Achilles tendonitis is a common irritation of the thick tendon located at the heel.

Another result of acute trauma to the foot is fracture of the bones within the foot. Fracture can be caused by sudden, excessive force, or by repetitive motion that eventually results in breakage. Repetitive trauma to the bones, muscles, and ligaments can also result in extra bone growth known as spurs or exostosis, plantar fasciitis, and acute and chronic osteoarthritis.

Bruises can also result from sudden trauma. Particularly when they occur in the heel, bruises can cause severe pain when an individual puts weight upon the bruised foot. Another cause of bruises is excessively tight footwear. For example, shoelaces tied too tightly can cause bruises across the arch of the foot.

Another cause of damage to internal and external structures of the foot is poor biomechanical alignment of the feet and body. Poor alignment can result from poor posture and gait. Poor alignment can also be caused by wearing shoes that are ill-fitting, tied too tightly, or high-heeled.

In addition to poor alignment, footwear can cause other mechanical injuries such as blisters, calluses, and bruising. Over time, damage from footwear can manifest as bunions, bony bumps at the base of the big toe, corns, round calluses of built-up dead skin, nerve irritation, ingrown toenails and misalignment of the toes.

A variety of diseases, ranging from common and manageable to infrequent and severe, can cause foot pain. Plantar warts, which appear on the soles of the feet, are caused by a virus and can result in pain. In certain people with diabetes, nerve damage can result in peripheral neuropathy within the feet. This is generally felt as pain, numbness and tingling. Diabetes can also cause inadequate circulation (ischemia) in extremities such as the feet, resulting in severe pain. Poor circulation deprives tissues in the foot of blood flow, leading to ulcers that are resistant to healing, tissue necrosis (death), and eventually amputation.

Nerves in the foot can also be affected by neuroma, a benign growth of nerve tissue frequently found between the third and fourth toes. Like peripheral neuropathy, neuroma can cause pain, a burning sensation, tingling, and numbness in the affected area.

Another common disease responsible for foot pain is gout. Gout is a complex form of arthritis characterized by sudden, severe attacks of pain, redness, and tenderness in joints, generally in the joint at the base of the big toe³. Gout occurs when urate crystals accumulate around the joint, causing the inflammation and intense pain of a gout attack.

In addition to gout, arthritis can produce other types of painful changes in the bones of the foot. According to the American Academy of Orthopedic Surgeons, osteoarthritis, also known as degenerative or "wear and tear" arthritis, is a common problem for many people after they reach middle age⁴. Over the years, the smooth, gliding surfaces covering the ends of bones (cartilage) become worn and frayed, resulting in inflammation, swelling, and pain in the joint. Similar to osteoarthritis is post-traumatic arthritis, which can develop years after a fracture, severe sprain, or ligament injury⁵.

APMA stresses that, whether a person is young or old, foot pain is not normal⁶. In order to combat foot pain, it offers the following tips^7,8:

• Inspect feet regularly.
• Wash feet regularly, especially between the toes, and dry them completely.
• Trim toenails straight across, but not too short.
• Make sure shoes fit properly.
• Wear the right shoe for specific activities (such as running shoes for running).
• Don't wear the same pair of shoes every day.
• Avoid walking barefoot, which increases the risk for injury and infection.
• It is critical that people with diabetes see a podiatric physician at least once a year for a checkup.
• Control weight: obesity puts extra strain on the feet.

References

1. "May 26, 2009." American Podiatric Medical Association. American Podiatric Medical Association, 2011. Web. 4 Jul 2011. www.apma.org/MainMenu/News/APMA-in-the-News.
2. "Arthritis of the Foot and Ankle ." American Academy of Orthopedic Surgeons. American Podiatric Medical Association, 09-2008. Web. 5 Jul 2011. www.apma.org/MainMenu/News/APMA-in-the-News.
3. "Gout." MayoClinic.com. Mayo Clinic, 04-04-2011. Retrieved 5 Jul 2011 from www.mayoclinic.com/health/gout
4. "Arthritis of the Foot and Ankle ." American Academy of Orthopedic Surgeons. American Podiatric Medical Association, 09-2008. Web. 5 Jul 2011. www.apma.org/MainMenu/News/APMA-in-the-News.
5. "Arthritis of the Foot and Ankle ." American Academy of Orthopedic Surgeons. American Podiatric Medical Association, 09-2008. Web. 5 Jul 2011. www.apma.org/MainMenu/News/APMA-in-the-News.
6. American Podiatric Medical Association. American Podiatric Medical Association, 2011. Web. 4 Jul 2011. www.apma.org/foot-pain.
7. "General Foot Health." American Podiatric Medical Association. American Podiatric Medical Association, 2011. Web. 4 Jul 2011. www.apma.org/MainMenu/Foot-Health.
8. "Study Finds Obesity in Children Increases Foot Injury Risk." American Podiatric Medical Association. American Podiatric Medical Association, 2011. Web. 5 Jul 2011. www.apma.org/Study-Finds-Obesity-in-Children-Increases-Foot-Injury-Risk.