Flat feet (flatfoot, pes planus, fallen arches) occur when the arch in your foot drops, causing the bottom of your foot to flatten. This is easy to note, as the entire sole of your foot will contact the floor when you stand. In many cases, flat feet are hereditary and cause no pain.

But for those who once had arches, Flatfoot slowly develops from wear and tear (aging) or trauma, causing pain in the arches, heels, ankles, knees or hips, as the leg and foot fall out of alignment. The culprit is usually damage to the posterior tibial tendon which runs along the inside of your ankle - when it weakens, it can no longer support the arch.

Why you need your arches

We all start with zero arch. We're born with flat feet and slowly our arches develop during childhood, becoming fully developed in adulthood.

The arches and the biomechanics of the lower leg are intimately linked - our arches literally put a "spring" in our step, determine how we walk and distribute our body weight proportionally across our feet and legs. Arches also need to be sturdy and flexible to adapt to various surfaces. When the strength or flexibility of the arch fails, the alignment and balance of the foot and leg suffers.

What causes flat feet?

The most common cause of Adult Acquired Flat Foot Deformity (AAFFD) is damage to the posterior tibial tendon, one of the most important tendons in your leg. Starting at the calf, the posterior tibial tendon travels down the inside of your leg and heel, and attaches to the bones on the inside of your foot. The main function of the tendon is to support your arch and foot. If the tendon suffers chronic damage such as persistent inflammation, it may lose its ability to support your arch, and the arch will slowly collapse. Pain and discomfort from AAFFD can be substantial, occurring anywhere in the foot, heel, ankle, knee, back, or hip.

Inflammatory arthritis, especially rheumatoid arthritis, attacks the cartilage in the joints as well as the ligaments that support the foot. The inflammation causes not only pain, but also may change the shape of the foot and cause the arch to drop.

Ligament injury causes the joints to fall out of alignment. The job of the ligaments is to hold the bones in place and prevent them from moving. When the ligaments are damaged, the bones fall, flattening the arch.

Fractures or dislocations of the bones in the midfoot can lead to Flatfoot deformity.

Charcot Foot Disorder, a complication of diabetes, results from a nerve condition (diabetic peripheral neuropathy) which causes a loss of sensation in the feet. An infection in the foot, unknown to the patient, causes weakness in the ligaments and bones, leading to collapse of the arch and other complications. Complicated surgery is required to correct the problem.

Other reasons for developing Flatfoot include

• Obesity
• Muscle diseases
• Pregnancy
• Aging
• Trauma

Symptoms of Flatfoot depend on the cause of the condition, but may include :

• Difficulty standing or walking for long periods, and pain that gets worse with activity. High intensity activities such as running can be especially difficult.
• Pain or achiness occurring anywhere from the mid foot, heel and arch to the hip and back.
• Pain along the inside of the foot or ankle (path of the posterior tibial tendon). May be accompanied by swelling.
• Stiffness in the feet
• Feet tire easily
• Standing on toes is difficult
• Pain on the outside of the ankle, caused by a shifting heel bone which puts pressure on the fibula (ankle bone)
• In the presence of diabetes, patients may discover a lump on the bottom of their foot. This may develop into an ulcer and consequently Charcot foot disorder. Any difference in the top or bottom surface of the foot should immediately be brought to the attention of a podiatrist

Treatment for flat feet

• Custom orthotics may be prescribed to support your feet correctly and reduce pain
• A change in footwear: Your podiatrist may suggest you buy a pair of high quality, supportive shoes to reduce stress on your feet and support them correctly
• Physical therapy to stretch the Achilles tendon. A short Achilles can contribute to Flatfoot, and stretching it will improve flexibility in the foot
• Surgery may be recommended to repair the arch and improve flexibility

Watch the story of how we alleviated the pain of Flatfoot (and other conditions) for one of our patients.