What's a fallen arch - and do you have them?

A lot of you have been asking about advice on running shoes for this summer, and I wanted to take a few moments to talk you through choosing the right trainer to start running, or to take your mileage up to the next level.

It’s easy enough to look for the ‘best trainer of 2020’ or the ‘Top 10 running shoes’, but once you’ve made your shortlist, you start seeing words like ‘arch support’, ‘neutral’ and ‘control’. So, let’s discuss what arches are, how they work and how they affect your running.

What are 'arches'?

Your feet actually have two arches each: and they’re a combination of bones, tendons and ligaments arranged in a curved shape. Just like the arch of a bridge, they act as both shock absorbers and upright supports; literally giving you the ‘spring’ in your step.

So, what’s a 'fallen arch'?

Your arches naturally support your weight, rolling a little on the inside as you walk. This is called ‘pronation’.

If your arches are low, or have collapsed, you’ll find your feet (and probably your knees) roll inwards as you walk. This is called ‘over-pronation’, and yes, ‘under-pronation’ is a thing too; it means your arches are higher than they should be.

Take a look at the scans below – you can see how pressure is distributed in over and under-pronated feet while they are in motion.

Low arched foot, red shows the greatest pressure on the instep and the big toe

For over-pronated feet, the low arch means that the ankle and the big toes are taking a lot of the strain when walking or running, while the nerves and blood vessels in the bottom of the foot are at risk of compression. Painful big toes, calluses and ankle pain are common.

High arched foot, you can't see a good deal of contact with the ground here

For under-pronated feet, the high arch means muscles in your lower leg take additional strain they weren’t designed to, and don’t offer as much shock absorption as they should. Ankle pain, heel pain and ‘shin splints’ are a common feature.

In both cases, the shock and impact of running is distributed to bones, muscles and tendons that aren’t optimised for it. Calluses form on the outsides of the big toes as they take the strain all five should be sharing, while you become tired far quicker than you should.

How can I tell which I am?

You can damp your bare feet with water and stand on a piece of dark Kraft paper (the packing paper in Amazon boxes is ideal). If you can barely see your foot shape, it’s most likely a high arch. If you can see most of it then it’s either low or collapsed. In-between is neutral. You may see places advertising scans like the ones above, but there’s already a tested, validated system in use worldwide that allows a trained Podiatrist to tell at a glance.

How it works, and how it helps you is our next topic!

Credit to the fantastic Tom McPoil, PT, PhD for the pressure illustrations