Flat feet
A flat foot is one whose inner arch has dropped, so that when you stand the sole meets the floor along almost its whole length.
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A flat foot is one whose inner arch has dropped, so that when you stand the sole meets the floor along almost its whole length. On its own this is neither an illness nor a verdict: a great many people are built this way and most of them walk, run and play sport without ever giving it a thought. The questions worth answering are different ones — why the arch is missing, whether anything has changed over recent months, and whether the foot hurts. Those three separate a normal variant from something that does need treating, and treating promptly.
Taking a look at your own feet
The easiest way is to assess the foot standing rather than sitting: under body weight the arch settles and the picture becomes honest.
- Stand barefoot in front of a mirror and look at the inner border of the foot. With a marked flat foot there is no gap at all between the floor and the foot.
- Wet your soles and step onto dry floor or paper. The print of an arched foot narrows in the middle to roughly half its width, while a flat foot leaves a broad unbroken band.
- Ask someone to look at you from behind. In a flat foot the heel rolls outwards, and from behind more toes are visible on one foot than on the other, an asymmetry that should not be there.
- Rise onto your toes. If the arch appears at that moment and the heel straightens, the foot is flexible, which is the commonest and most harmless version. If no arch appears, the foot is rigid, and that one does need a doctor.
- Look at the soles of your old shoes. Heavy wear along the inner edge of the heel says the load is being shared unevenly.
Check separately whether you can rise onto the toes of one foot while steadying yourself against a wall. Being unable to do so is an important sign, and we come back to it shortly.
In children it is usually normal
Almost all small children look flat-footed, for two reasons: the arch has not formed yet at that age, and a soft pad of fat fills the sole and hides the arch even where it already exists. The arch emerges gradually, roughly between three and ten years of age, and in some children only settles into its final shape in the teens. In others it never appears at all, and that too is an inherited pattern of build.
From this follows a practical conclusion that saves families a good deal of money: a child who does not complain, who runs level with friends and tires no more than they do needs neither orthopaedic boots nor rigid insoles nor courses of massage for the arch. Insoles do not build arches, and this has been tested more than once. Something else is more useful: plenty of barefoot walking on uneven ground, on grass, sand and shingle, and light shoes with a flexible sole that let the foot do its own work.
A child is worth showing to a doctor, though, if the feet hurt, if the child avoids walks and asks to be carried more than others of the same age, if only one foot is flat, if the foot is stiff and does not correct on tiptoe, if the child habitually toe-walks or seems notably clumsy. These features speak not of the flat foot itself but of the cause hiding beneath it.
When a flat foot starts to get in the way
In adults the complaints arise not from the arch itself but from overload of the tissues doing its job for it. The typical picture runs like this: by the end of the day the inner border of the foot and the ankle ache, the inner side of the shin pulls, and in the morning the first steps hurt in the heel. The knee may tire and hurt, less often the hip and the lower back, because the foot rolls inwards, the leg turns after it and the chain carries upwards. Hard skin builds on the sole and under the big toe, shoes wear out lopsided, and the feet swell towards evening.
The trigger is rarely the foot itself and usually a change in load: a new job spent standing, weight gained, pregnancy, a sudden jump in running mileage, a switch to flat unsupportive shoes. In many people the pain settles as soon as the load returns to its earlier level and the footwear is chosen with more care.
When another illness lies behind the flat foot
There are several situations in which a flat foot is not a quirk of build but a symptom. They are worth recognising, because here time works against you.
- An arch that collapses in adult life, most often on one side only. Behind it usually lies wear of the tibialis posterior tendon, the very tendon that holds the arch up. It begins with pain and swelling on the inner side of the ankle, after which the foot slowly flattens and turns outwards. The early sign is being unable to rise onto the toes while standing on that leg alone. Early on, insoles, a brace and exercises help; later the joint stiffens and only surgery is left. Months separate the two stages, so delay is costly.
- A stiff, painful foot in a teenager that does not correct on tiptoe. That is how a fusion between the tarsal bones announces itself, a congenital feature that makes itself felt as those bones harden.
- A foot that flattens after an injury to the midfoot: a twist, a landing from height, a crush. Ligament damage there is easily missed, and untreated it leaves a lasting deformity.
- Swollen painful joints, morning stiffness and both feet flattening in an adult may point to rheumatoid arthritis.
- Diabetes deserves its own paragraph. If someone with diabetes and reduced sensation in the feet notices that one foot has become hot, red and swollen and that its shape is visibly changing over a few weeks, with little or no pain, this is a Charcot foot. The bones inside such a foot break down and collapse under body weight. It is uncommon, but it is precisely what ends in severe deformity and amputation, and it responds far better the sooner the foot is taken out of weight bearing. Do not wait for a booked appointment; seek help at once.
Nor should numbness, tingling or burning pain in the sole be blamed on flat feet: that belongs to the nerves and is looked into separately.
What helps when the foot hurts
The shape of an adult foot cannot be changed by exercises or insoles. What those manage is the symptoms, and at that they do well.
- Footwear. You want a wide last with a firm heel counter that stops the heel rolling over, a stable sole and little heel height. Ballet pumps, flip-flops and entirely flat unsupportive shoes are no use while there is pain.
- Insoles. Off-the-shelf arch-supporting insoles often bring clear relief and are the sensible place to start; custom-made ones are for when the ready-made kind has not worked or the deformity is marked. Break them in gradually, beginning with an hour or two a day.
- Exercises. Daily calf stretching, since a short Achilles tendon often keeps a flat foot company, heel raises, the short-foot exercise, rolling a ball under the sole, walking on the outer border of the foot. This has to be kept up for months before it pays.
- Load and weight. Every extra kilogram passes through the foot thousands of times a day. While it hurts, swap running and jumping for cycling or swimming, then build back up in small steps.
- Pain. Cold after activity helps, as do short courses of over-the-counter painkillers; which one suits you is best checked with a doctor or pharmacist.
- Specialists. A podiatrist and a physiotherapist fit footwear, insoles and an exercise programme. Surgery is used rarely: for a rigid painful deformity, for fused bones, or for advanced tendon damage when everything above has failed.
Online consultation
The main question sorts itself out well at a distance: is this a variant of build that needs nothing done about it, or a situation calling for examination and imaging. The doctor works through how long the foot has looked like this, whether it is one foot or both, what happens on tiptoe, how the shoes are wearing and what the onset of pain coincided with, and photographs of the feet from the front and from behind show a great deal. The consultation covers which shoes and insoles to buy and which exercises to do, plans the return to running, and clarifies whether a face-to-face appointment is needed and with whom. It is also worth asking online if you are a parent unsure whether your child's feet are normal, since it saves money wasted on so-called orthopaedic shoes. A hot swollen foot in someone with diabetes, and a foot deformed after injury, need examining in person and will not wait.
This material is for information only and does not replace medical advice.
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