Optimizing for Feet Health and Function

July 30, 2023

We usually don't think of our feet too much. At most, they're an opportunity to buy cool shoes. But a few months ago, I suffered a turf toe injury that failed to heal. Months later, I still couldn't bend my big toe. This led me down a rabbit hole of trying to understand everything I could about our feet and what makes them perform ideally. This article is a compilation of everything I learned and what I wish I had known earlier.

Back to baby feet

An essential characteristic of healthy feet is that they should be widest at the top of your toes. We all know this from looking at baby feet that haven't been in shoes.

Yet, most of our feet are widest at the base of the toes, not at the very top. This isn’t how they are supposed to be. If you search for pictures of adult feet that have never been in shoes (for example, from tribes that don’t even know what a shoe is), you’ll see shapes similar to those of babies.

Why would we use footwear that's not ideal for our feet? There are two main reasons.

1. Style

Narrow footwear with a pointed toe has been in and out of fashion for centuries with a rich history during the middle ages https://en.wikipedia.org/wiki/Poulaine. As with anything fashionable, it is hard to determine what made it popular. A hypothesis is that by its nature, such footwear was impractical for any worker, especially peasants, which made it a status symbol for the nobility. What makes this theory fascinating is that our modern footwear would therefore be bad for our feet not as an unfortunate consequence but by design. And interestingly, a study found that our ancestors who used those shoes experience feet issues similar to what we do today.

To this day, shoes that are narrower at the top are considered the most aesthetically pleasing. That's why dress shoes for both men and women emphasize this feature the most. This realization came as a huge surprise to me. Until now, I had been purchasing running shoes from Nike to use as my everyday shoes. I assumed they must be good for my feet. After all, who knows better than Nike what my feet need?

2. Unfrequent and delayed problem

If ordinary shoes caused problems within a few weeks, we wouldn't continue using them. However, they don't. Most people can wear these shoes for most of their lives and never experience significant issues. Even when problems arise, it is decades after we've started using shoes, making it harder to blame them. Additionally, now that foot problems are common, it is seen as one of those things that you get as you age. We've become fatalistic.

The problem with a narrow toe box

Ordinary shoes have a narrow toe box that prevents your toes from splaying. This small esthetic difference has numerous downstream consequences, as it can lead to bunions, hammer toes, more blisters, more calluses, ingrown toenails, metatarsalgia, plantar fasciitis, neuromas, etc.

The implications of narrow toe boxes is still uncertain, and even common afflictions such as plantar fasciitis don’t seem to be well understood. For example, plantar fasciitis was thought to be an inflammatory disorder, but a 2003 study failed to find any evidence and concluded that it was instead a degeneration of the fascia. Some believe the narrow box pushes the big toe inside, restricting blood flow to tissue at the bottom of the feet.

Another consequence of crushing the toes together is losing a lot of stability. You can try this by moving your big toe and noticing how unbalanced you are when the toe is crushed inside. This becomes a problem in sport in particular: Squatting, for example, benefits from maximizing your stability (which is also why it’s frequently recommended to do so barefoot as you give more space to the big toe and avoid the instability brought by the cushioning of shoes).

Finally, pushing the big toe inside limits your arch size (this is something you can also try). This can be a significant difference for those with a smaller arch.

For all those reasons, despite some scientific uncertainty, it makes sense to go with shoes that better fit our intended anatomy.

Making your toes splay

Finding the right shoes

The first step to have your toes take the shape they are supposed to is to stop crushing them inside a shoe that’s too narrow. A good way to know if your current shoes are a good fit is to take out the insole and splay your toes. If you’re outside, then it means you need more space.

Pictures 1 and 2 are of insoles from Brooks running shoes that got selected for me at a good running shop. Pictures 3 and 4 are for custom orthotic insoles an orthopedic doctor had made for me (and yet they are even tighter!). Picture 5 is the insole of Altra running shoes.

They are now a decent amount of brands that offer wide toe boxes. For running, I’ve been happy using Altra.

Toe spacers

If you’ve been cramming your feet in narrow shoes for decades, giving them some space won’t instantly bring them back to a normal shape. For this, there exist numerous toe spacers. Their goal is to speed up the spacing of your toes. However, not all toe spacers are the same, and they are two characteristics that I would suggest looking for:

The ability to wear the toe spacers all day even if you’re working out: This will maximize their effectiveness as you’ll have them on longer. It’s also easier to get in the habit of wearing them if you can wear them continuously regardless of what activity you're doing.
They should be adjustable to increase the spacing depending on your goals.

I’ve been using the toe spacers from Correct Toes, and they fit those criteria nicely. I put them on at the start of the day and remove them before going to sleep. After a few days, you don’t even notice you’re wearing them (I'm even running with them).

Notice at both extremities the small openings. Those can be used to extend the toe spacers depending on the shape of your feet.

A note on socks

Most socks we use have elastic, and it stands to reason that even in a wide toe box, this pull would prevent the toes from fully splaying. If you're using toe spacers, this doesn't apply. But if you aren't, it might make sense to look for better socks.

The most ridiculous option out there is toe socks. They fully allow toe splay and have the side benefit of preventing chafing and blisters, which can be great if you do a lot of hiking or running. The only downside is how they look, which might be a deal breaker for some.

Alternatively, some brands now have anatomically correct socks with a wider toe box. I haven’t tried them yet.

Toe socks are very comfortable but are known to cause divorce.

Zero drop shoes

Enough on toes! The shape of the sole also matters. Zero-drop footwear promises to be a better alternative to what we currently use. They are shoes with no height difference between the heel and the toe, similar to our feet.

Why are current shoes not designed this way? Historically, as running became more mainstream in the latter half of the 20th century, shoe manufacturers looked for ways to make the activity more comfortable. Adding cushioning to the heels to absorb shock and reduce the impact on the joints seemed to make sense. When we try on shoes with lots of cushioning, we intuitively feel they will have a protective effect. Biomechanical theories also supported this innovation, suggesting that raising the heel would reduce the stress on the Achilles tendon and calf muscles.

In parallel, marketing played a role in popularizing these shoes: Manufacturers promoted the supposedly advanced technology used in their shoes, which was achieved then by marketing thicker and more cushioned heels. To be fair, we are now seeing a reversal of this trend, with minimalist and more "natural" shoes becoming trendy.

At this time, there is no definitive evidence on what is best. The answer might change based on your goals: Even if raising the heel is not ideal if it allows you to run slightly faster, runners would justify the purchase. What is clear, however, is that zero-drop shoes change the foot position, foot strike pattern, and gait. I know this fits into the naturalistic fallacy, but I prefer to use the more natural option when in doubt. In this case, our feet evolved from hundreds of thousands of years of walking barefoot without a raised heel. Unless there is good evidence, I will buy shoes that fit this design.

Minimalist/barefoot shoes

Minimalist shoes have gained a lot of traction over the last few years. By definition, they are supposed to mimic natural walking and have minimal soles and minimal or no cushioning. This means they incorporate the two characteristics we discussed: zero drop and wide toe boxes.

Does the minimal sole bring any benefit? If you try those shoes, you'll clearly notice the ground under your feet. This is suggestive, but I personally very much like the feel. Wearing those shoes also strengthens your feet. By its nature, it also ensures the foot mechanics is more natural as you’re almost barefoot.

But here again, they are no conclusive evidence proving barefoot shoes are supperior. If we go back to thinking about what’s natural, it would make sense to prioritize being barefoot, but with a few caveats:

Our environment is different than the one of our ancestors: If you live in a city, you might spend your time on hardwood floors and concrete. This isn’t natural, and your body didn’t evolve for it.
Our activities compound this challenge: If you run a lot on concrete or do rucking, you are loading your joints in a way that would maybe benefit from more cushioning.

For now, my position is to continue walking barefoot at home as I’ve always done. Outside, I’ll use the cushioning from shoes, especially when running or rucking.

Conclusion

I find it fascinating that a topic as mundane as footwear is laden with uncertainty. From researching this topic, I take away a few lessons:

Shoes should have a wide toe box
Spending some time every day walking barefoot (even if just at home) is beneficial
Zero-drop shoes should be preferred

I love tracking things, and I've taken pictures of my feet. Hopefully, I can check in a few years to share my progress.

#health