Why are my feet flat?

Adult-acquired flat foot is a condition that results in a fallen arch and the foot pointed outward.  This condition is most common in women over the age of 40.  A variety of foot problems can lead to adult acquired flatfoot deformity but the most common cause is a gradual stretching out of a tendon near the ankle bone, known as the posterior tibial tendon.  This tendon is the main stabilizer of the foot arch.  While the cause of the stretching is not fully understood, many doctors believe that wearing high heels and standing or walking for long periods may add to the problem.  Other risk factors include obesity, hypertension, and diabetes.


People with flatfoot experience different symptoms depending on the cause.  Pain and swelling may be felt on the inside of the foot and ankle.  This pain points to involvement of the posterior tibial tendon.  The pain may increase with activity and high intensity activities such as running can be very difficult.  As condition worsens, the arch can collapse causing the heel bone to move, and placing pressure on the outside of the ankle.  This can cause outside ankle pain and arthritis of the ankle joint.


The posterior tibial tendon is one of the most important tendons of the leg.  It starts at a muscle in the calf and travels down the inside of the ankle and attaches to bones on the inside of the foot.  The main function of this tendon is to support the arch.  If the tendon becomes inflamed or torn, the arch will slowly collapse.  Inflammatory arthritis can attached the ligaments as well as the cartilage in joints.  Arthritis can cause pain as well as changes to the shape of the foot.  Injury to the ligament sin the foot can cause joints to fall out of alignment and cause flat foot.  The last major cause of adult-acquired flat foot is diabetes.  People with diabetes or with a nerve loss can have arch collapse.  This is typically more severe and due to a loss of pain sensation as the arch collapses.


Adult-acquired flat foot is a very common problem affecting the foot and ankle.  The good news is orthotics and braces can help most people.  For people that have tried orthotics and braces without any relief, surgery can be a effective way to reduce pain and deformity.  Your podiatrist is specially trained in treating flat foot and will create a custom treatment plan.