Flat Feet (Pes Planus): Treatment in Children and Adults

An arch rises along the inner edge of the foot between the heel and the bases of the toes. Supported by bone alignment, ligaments and tendons, particularly the tibialis posterior tendon on the inner side, it acts like a shock absorber that stretches and recoils during walking. Flat foot (pes planus) is marked lowering or complete loss of this arch when standing; the heel often tilts outwards.

Flat foot is a foot posture rather than a single disease. Distinguishing two forms guides treatment. In flexible flat foot, the arch reappears when the foot is off the ground or on tiptoe; the foot is supple and mobile. In rigid flat foot, no position restores the arch and movement is restricted; an underlying structural cause is investigated.

Flexible flat feet are common and usually cause no symptoms. Symptom-free flat feet require no treatment; pain and loss of function, rather than the X-ray appearance, guide decisions.

When symptoms occur, the most common descriptions are:

• Pain in the sole and inner foot after prolonged walking, standing or sport
• Swelling and tenderness on the inner ankle
• Rapid wear on the inner edge of the shoe sole
• Fatigue and pain in the calf, knee and lower back
• Difficulty rising onto tiptoes or standing on one foot
• In children, avoiding long walks, asking to be carried and tiring quickly while running

Babies are born with flat feet. The arch develops gradually from the first years of walking and becomes more apparent towards school age in most children; in some it develops until adolescence. A flat-looking sole in a young child is not itself a disease. The fat pad under young children's feet also hides the arch, giving a flat appearance.

Families most often ask whether insoles are needed. There is no strong evidence that insoles permanently change the arch in children with painless, flexible flat feet; routine insoles are therefore not recommended for children without symptoms. Insoles may be used to relieve pain in children who have discomfort or complain after prolonged walking. Flexible-soled shoes that do not squeeze the feet are sufficient; walking barefoot on uneven surfaces such as grass or sand exercises the foot muscles.

Assessment focuses on warning signs: one-sided flat foot, pain, stiffness, a short Achilles tendon, significantly altered walking and worsening symptoms. If any are present, causes other than flexible flat feet are investigated. For other walking issues, such as intoeing and toe walking, see intoeing and gait disorders in children.

Painless flat feet present since childhood and newly developed flat feet in adulthood are different conditions. The most common cause of adult arch collapse is dysfunction of the tibialis posterior tendon, which passes along the inside of the ankle and supports the arch. Excess weight, prolonged standing at work, diabetes, rheumatic conditions and previous injuries increase the risk.

Early on, pain and swelling affect the inner ankle while the arch remains flexible. As the condition progresses, the heel shifts outwards, the forefoot turns out and the foot gradually stiffens; the ankle joint may also deteriorate in advanced stages. New adult flat foot and inner ankle pain should therefore not be ignored.

Treatment depends on the stage. In early disease, reducing load, using an arch-supporting insole or ankle brace, following a tendon-strengthening programme and managing pain are sufficient for most patients. If the foot has become stiff, the deformity has progressed and pain cannot be controlled with non-surgical measures, surgical options are discussed: tendon repair or transfer, corrective operations on the heel bone and, in advanced cases, fusion of selected joints. The decision depends on foot flexibility, stage, age and expectations.

Examination compares the arch while standing and with the foot unloaded, includes a tiptoe-rise test and assesses heel alignment from behind. Achilles tightness and foot joint range of movement are checked to distinguish flexible from rigid flat feet.

If symptoms are present, standing weight-bearing foot X-rays show bone alignment and joint condition. For a rigid foot, CT may identify bridging between bones, while MRI assesses tendons and ligaments. Imaging is generally unnecessary for painless flexible flat feet.

Tarsal coalition is a connection between bones at the back of the foot, most commonly between the heel bone and ankle-region bones, through a bridge of bone, cartilage or fibrous tissue. It is present from birth, but symptoms usually begin in the second decade of life as the bridge stiffens. The typical pattern is an adolescent with recurrent ankle sprains, a rigid flat foot and increased pain after sport.

Restricted foot movement is identified on examination, and the diagnosis is confirmed by CT or MRI. First-line treatment is non-surgical: activity modification, arch-supporting insoles, a period of rest in a splint or cast, and pain management. If symptoms persist, surgical removal of the bridge or, in selected cases, corrective joint procedures are considered. This issue is assessed separately during consultation, and planning follows the imaging findings.

An accessory navicular is an extra small bone present from birth beside the navicular on the inner side of the foot. It occurs in some people and often causes no symptoms. The tibialis posterior tendon, which supports the arch, attaches to it, so strain or shoe pressure can make it noticeable as a painful prominence on the inner foot. It often accompanies flat feet and most commonly becomes symptomatic during adolescence.

Diagnosis is made by examination and X-ray; in uncertain cases, MRI assesses local oedema and the tendon. Treatment starts non-surgically: footwear that relieves pressure, an arch-supporting insole, reduced loading during painful periods and, when needed, a short period in a splint. Persistent symptoms may require removal of the accessory bone and appropriate tendon repair. This condition and tarsal coalition are assessed together according to foot stiffness and the location of pain.

Simple exercises for the sole and calf muscles, such as heel raises, gathering a towel with the toes and calf stretching, support the structures maintaining the arch. Weight management directly reduces foot loading. Cushioned, arch-supporting shoes can help people who stand for long periods.

Assessment is needed if foot pain persists for several weeks, flat foot develops on one side only, the foot becomes rigid or a child's gait deteriorates noticeably. You can book by telephone or WhatsApp at AC CLINIC in Altınordu, Ordu, for paediatric and adult foot assessment, planning of weight-bearing X-rays, and an insole and exercise programme.