Flatfoot, also known as pes planus is a postural deformity that arises when the arches of the feet are flattened, allowing the soles of the feet to rest on the floor when standing. It occurs in 20% of adults and also common in young children with a small longitudinal arch. People with flatfoot have no or very little foot arch. Their feet may roll over to the inside when standing or walking.
There are two main types of flatfoot: flexible flatfoot and rigid flatfoot.
Flexible flatfoot is usually diagnosed during childhood, and it is likely to affect both feet. In cases of flexible flat foot, the lack of a visible arch is apparent when the individual is standing. However, the arch will be visible if the person tiptoes or flexes the arch. Those with rigid flatfoot have visibly flat feet under all circumstances. Rigid flatfoot in adults is called “adult acquired flatfoot deformity”.
Common causes of flatfoot include:
Hereditary factors (it can run in families)
Abnormal development of the foot arch during childhood
Wear and tear over the years can weaken tendons inside the ankle that support the arch
Weak arch structure
Nervous system or muscle disorders such as muscular dystrophy, neuropathy or spinal bifida
Pregnancy (hormonal changes)
Diabetes, obesity, and aging
Flatfoot may be asymptomatic, aside from the apparent flatness and possibly uneven wearing of shoes. However, some individuals will experience heel pain, or tenderness in the arch. While walking, patients may also roll the foot and ankle inwards, causing calf or knee aches as a result of the bio-mechanical interdependencies. Swelling and stiffness are also common.
Patients are advised to use conservative treatments like switching to supportive shoes, wearing arch supports (orthotic devices), and taking over the counter medication to manage pain symptoms. There are also exercises that are effective in stretching and lengthening the achilles heel (which helps pronate the foot), as well as walking barefoot and performing calf raises to build strength and flexibility.
Surgical intervention may be necessary if severe pain persists, or if the patient wants to prevent progression.