Flat feet: when they matter and when they do not

Two different situations

Flexible flat foot is the common kind. The arch appears when you sit or rise onto your toes and flattens when you stand. Many people have this from childhood, never develop symptoms, and need no treatment at all.

Adult acquired flat foot is different and more important. Here an arch that existed is collapsing, usually because the tendon on the inside of the ankle that holds it up is failing. It tends to progress, and it is much easier to manage early.

The signs that matter

Pain and swelling along the inside of the ankle, below the bony bump, is the classic early sign of that tendon struggling. People often describe it as an ankle problem rather than an arch problem.

A foot that is becoming more flat over months or years, or one where the heel appears to roll outward when viewed from behind. Shoes wearing down heavily on the inside edge.

Difficulty rising onto the toes on one leg, when you could before, is a practical test that often reveals the tendon is not doing its job.

Pain that has moved from the inside of the ankle to the outside is a later sign and a more urgent one. It usually means the heel has drifted far enough outward that bone is now contacting bone on the other side of the joint.

Watch the heels from behind in a mirror, or have someone look. Seeing more toes on the outside of one foot than the other, sometimes called the too many toes sign, suggests the forefoot has drifted outward relative to the heel and is a simple thing to notice at home.

What treatment involves

Supportive footwear with a firm heel counter is the foundation, because a soft shoe lets the foot do exactly what you are trying to stop it doing.

Custom orthotics are made for this specifically. Rather than propping the arch up cosmetically, they control how the foot rolls through each step, reducing the load on the tendon that is failing.

Where the tendon is already inflamed, a period of immobilisation to let it settle is sometimes needed before strengthening begins. Caught early, this is usually managed without surgery.

Strengthening the tendon once the inflammation has settled is part of the treatment rather than an optional extra. Heel raises, performed carefully and built up gradually, restore the capacity the tendon lost while it was painful.

Flat feet in children

Most young children have flat-looking feet because the arch develops through childhood, and a fat pad fills it in the meantime. The majority need no intervention.

Worth having looked at: pain, a child who avoids activity or tires unusually quickly, a foot that is rigid rather than flexible, or a difference between the two feet. Those are the ones where early assessment is useful.

A flat foot that cannot be moved into an arch position, in a child or an adult, always warrants assessment. Rigidity suggests the bones are connected in a way they should not be, which is managed differently from a flexible flat foot and is easier to address earlier.