Pain on the bottom of your foot isn’t always plantar fasciitis.
The foot and ankle contains more than one hundred muscles, tendons, and ligaments. The fascia that takes the blame for so much of the pain that develops on the bottom of the foot is just one in that group of one hundred plus.
Not knowing what other soft tissue could be hijacking your foot function can be a real problem. It can keep you from solving your pain issue, and can keep you from really maximizing your movement potential.
It’s usually impossible to make “if x then y” absolute statements regarding fitness and health; however, if you have flat arches, a bunion, turf toe, or pain on the soles of your feet, it might be something other than your plantar fascia that’s causing your problems.
When The Foot Becomes Dysfunctional
“Strong Feet” is one of the 6 Pillars of Strength; they are the base upon which you stack the rest of your body, they are an important feedback tool for your body to adjust how the rest of the skeleton functions, and yet they are so often stuffed into shoes and ignored.
With over one hundred different elements that make up the soft tissue of the foot and ankle, it’s incredible that so much of the blame for foot pain gets tossed on the plantar fascia.
The pain in your foot could be coming from your calf muscles that don’t have enough usable length or strength in them.
The pain might be coming from a toe mobility issue that is making your foot alter how it interacts with the ground.
I’d like to introduce you to another muscle in your foot that could be causing your foot pain.
Meet the flexor hallucis brevis.
The flexor hallucis brevis attaches on the base of the big toe (specifically, the proximal phalanx of the hallux), and runs back to the cuboid bone and the cuneiform bone in your mid foot. And if you take a look at that first word of the name of the muscle, ‘flexor’, you’ll see exactly what movement the muscle does.
It flexes the hallux, that is, it makes the big toe bend downward!
But the flexor hallucis brevis isn’t responsible for the scrunched up big toe bending you’re likely attempting to do right now as test your big toe function. That’s the flexor hallucis longus and it’s also very important to foot function – but I’ll save her for the next conversation on feet.
Watch the video below to see the difference between each muscle’s ability to flex.
Pain Points For the Flexor Hallucis Brevis
I see a lot of feet in my coaching (in training with me, we always look at your feet and bring your foot strength up to snuff) and in thirteen years I’ve noticed that it’s very common for clients to have lost the ability to fire the flexor hallucis brevis.
Remember that your muscles are what makes your joints move, which is what makes you move. If you lose the ability to use one muscle, you’ll alter how the joint that muscle is attached to will function. Losing how your big toe joint functions affects key parts about how your foot works, and thus, how you move:
- Your big toe is the last part of your foot that is on the ground as you move through a gait cycle. When the flexor hallicus brevis doesn’t work, it reduces your ability to push off the ground. Less push equals less power.
- When a muscle is weak, it can change its length to be shorter or longer. At the same time, other muscles will get stronger in compensation for the weaker muscle. You have three muscles that connect to your big toe. Altering of the length-tension relationship of any one of them will change how the big toe functions.
- Your big toe was created to face forward as it also acts as a key point of stability for your body. If the big toe starts to face any direction but forward, as is the case when the adductor hallucis muscle gets stuck in the shortened position, pulling the big toe towards the other toes (and eventually creating a bunion), the way you stabilize yourself will change. Changes in stabilization capability down at the foot will affect how you stabilize upstream in your body.
- Your flexor hallucis brevis plays a role in arch support. Lose function in that muscle and you lose arch height. Lose arch height and the entire contact between your foot and the ground changes. This means load dispersement on to your foot will change and that is a huge problem for the hard and soft tissue of your foot, as well as things far upstream – like your knees.
You can also experience pain behind the big toe joint (the area where many folks just assume the plantar fascia attachment site is flared up).
You could also experience pain on the top of your foot, near the big toe.
You can also experience pain along the sole of your foot as other muscles and soft tissue in your foot compensates for your lost capacity of your flexor hallucis brevis. This is very similar to how you can experience pain in your IT Band due to muscles of the leg and hip not working well. Remember, your body does not live in a vacuum. What happens in one area will affect another area.
Solutions For Better Big Toe Movement Quality
I’ve made you a video to help you know how to take care of two important components of the flexor hallucis brevis. For the mobility work I show, I’m a fan of ‘more often’ to answer the question of “how often should I do this?”. For the strength work, ‘daily’ makes a lot of sense to me until you get to a place where doing the movements is easy, and then going to checking on the movement quality semi-regularly.
(My personal experience is not a prescription for you, but, for reference – I did these items daily while I was rebuilding the arch of my right foot years ago, then moved to 3-4 times per week once I arrived in the land of “better, stronger, feet”. And now I do them only once in a while when I want to check in on my feet.)