Corns and calluses
by Gabriel Ariciu, DC
In honor of Foot Health Awareness Month, I decided to talk about feet! Yes, it is very exciting and like you I didn’t know there was a food health awareness month. But it gives me a great opportunity to talk about a very important aspect to health. It may seem nuanced but our feet provide the foundation upon which everything else rests. Poor foot health can lead to further problems up the chain in our knees, hips, spine, and shoulders. As you all know from reading my other articles, our body is interconnected and interdependent. You cannot affect just one system or body part.
Like many of you I used to never give much thought to foot health or even footwear. Growing up I would wear shoes that were a size bigger to grow into and they were usually athletic shoes of some type. When I started skateboarding I moved into the flat bottomed, no arch support, thick padding skate shoes. I remember getting lots of ingrown toenails during this time not really linking it to how tight my shoes were and the lack of going barefoot. Of course, skateboarding is rough on the feet too and I am not saying you shouldn’t skateboard. It is a sport I still love to watch. But I will give some pointers later on in regards to it.
Later on I chose to be a missionary in South Africa for two years. I wore durable dress shoes with arch support for the majority of that time and we did a lot of walking, I mean a lot. Surprisingly, never had any foot pain or muscle weakness from wearing the arch supports which I would learn is a common issue with arch supports. In Chiropractic school, I began to be exposed to the importance of proper footwear and foot health. As I learned the nuances of it I began to transition to minimalist shoes. The keyword here is transition, more to come on that point. From minimalist shoes, I transitioned into going barefoot and even wearing more barefoot style shoes which have a very thin sole on the bottom with no heel. After awhile the muscles in my feet began to be stronger. My arch became very strong and I was able to start splaying my toes again. Something you may notice with your little ones. Young children often have strong arches and they can splay their toes very well. Something that is harder for many of us who have gotten used to wearing tight fitting shoes.
In this article, I will talk all about feet, the anatomy, how they function, and proper care. But first let me mention some of the common problems people, and quite possibly many of you, have experienced with their feet.
Common Foot Problems
So what are some common ailments people deal with because improper footwear and health?
If you have any of the above issues, I hope to give you some helpful information in regards to them. Otherwise, this information is good for everyone and there is always more to learn about optimizing our health.
The Anatomy of the Foot
There are 26 bones and 33 joints within our foot and ankle. It is a complex structure. Many of you may think there is a few basic motions mainly dorsiflexion and plantarflexion or up-and-down. But is a more a joint complex. The ankle joint is made up of the fibula, tibia, and talus. The talus is an interesting bone in of itself, it has no muscular attachments and plays an important role in our flexor withdrawal reflex when we are in danger of being injured. This part of the ankle is the talocrural joint. Below it is the talocalcaneal joint or subtalar joint. The subtalar joint is made up of 3 facets; the posterior (back), middle, and anterior (front). This allows for triplanar motion.
The talocrural joint allows for the up-and-down motion while the subtalar joint helps us by providing mobility when walking over varied surfaces. Think of when hiking on a steep, rocky terrain. You need ankle mobility to accomplish this well. The rest of the bones and joints of the foot are important too each working together for that firm foundation we are seeking.
There are several muscles that act on the foot and ankle that are very important to highlight. Most of these originate in the leg. The intrinsic muscles of the foot itself are important too but I am going to focus on some of the big players.
Firstly, the tibialis posterior. This muscle originates from inner posterior portions of the fibula and tibia attaching to the interosseous membrane that lies between the two bones as well. The muscle tendon wraps behind the medial malleolus inserting itself to several bones on the plantar side of the foot, specifically the navicular, calcaneus, the cuneiforms, cuboid, and 2nd, 3rd, and 4th metatarsals. When speaking of origin and insertion, please understand that this a specific term for something that is more general. Because of ligaments, tendons, and fascia, the origins and insertions are broad points of contact that interact with the surround structures in a variety of ways. That being said there are a couple of main actions the tibialis posterior muscle performs. It is responsible for inversion and assisting in plantarflexion of the foot. It also plays a very important role in supporting the arch of the foot. This is where I see it commonly. Many who deal with fallen arches and overpronation have an issue with their tibialis posterior. Abductor hallucis, the muscle that holds our big toe out, is another common cause.
The soleus and gastrocnemius are the muscles that make up your calf. The gastrocnemius acts on both the knee and the ankle joints but the soleus only acts on the ankle. However, that being said remember what I said above. I am applying specific terms or simplifying complex anatomy. The soleus originates on the fibula and medial tibia. The gastroc, divided into two heads, originates just above the medial and lateral condyles of the femur. They share a common insertion via the achilles tendon onto the calcaneus. Together their action is to plantarflex the foot. The gastroc also assists in knee flexion. I am sure many of you have seen many athletes suffering from achilles tendon tears and ruptures.
Some other muscles that play an important role are tibialis anterior, which helps with inversion and dorsiflexion and the fibularis muscles which help eversion, dorsiflexion, and plantarflexion. I won’t go into detail with these, hoping that the above details illustrate the point that our feet are part of a complex system of muscles, joints, ligaments, etc., all providing us with the ability for mobility, support, and movement. It is very important to take care of our feet!
Our feet several different functions, some of them I have mentioned. I want to get rid of the misconception that people have genetically weak ankles and wrists. I thought this for a long time about myself but in reality it is because I was weak physiologically, meaning, I could overcome it with a bit of work. Almost always this is the case. If you think you have weak ankles, you may, but please do not think that there is no way to overcome it. “The opinion that the lower extremities are inherently fragile goes against the authors’ understanding of the concept of natural selection.” (1)
One of the most important functions of our feet is mechanoreception. Mechanoreceptors are sensors that detect change in mechanical pressure. These include Ruffini endings, Pacinian corpuscles, Meisner’s corpuscles, Merkel endings, golgi tendon organs, muscle spindle cells, free nerve endings, and 4 types of specialized joint receptors. These all serve different purposes some detect pain and temperature which utilize the anterolateral pathway, others detect fine touch and proprioception. I will focus on the latter. These utilize the DCML pathway.
When they are activated in the feet a signal is transmitted to the dorsal root ganglion, which is near the spinal cord, and out to another neuron in the dorsal column of the spinal cord. This neuron transmits the signal up the spinal cord via the the DCML (dorsal column-medial lemniscus pathway) in the gracile fasciculus ipsilaterally. They travel to a neuron residing in the ipsilateral gracile nucleus located in the medulla in the brainstem. This neuron responds by sending a signal across to the contralateral side of the brainstem and up to the thalamus via the medial lemniscus. There it acts on another neuron which sends a signal to the contralateral post central gyrus of the cortex which is the primary sensory structure of the brain. It is amazingly complex and wonderful! Funny thing is, that was a simplified explanation! Other neurons are acted upon with signals being sent up and down the spinal cord to respond to this stimulus.
The thing is, thousands upon thousands of these signals are being sent all the time! Outside the upper cervical region of the spine, the feet have some of the highest concentration of mechanoreceptors in the body. Which brings me back to proprioception. Proprioception is the sense or awareness of where our body is in space. It is the ability to know what position we are in and movements we are making independent of vision. Our balance system is achieved by the integration of proprioception, vision, and the vestibular system. The breakdown of any one of these causes issues with our balance. Our feet have a high concentration to aide in this system. They need to be able to feel the terrain we are walking on. To respond appropriately to what could injure us. To aid in reconfiguring our movement when changing directions, moving rapidly, and lifting heavy objects. Loss in foot mechanoreceptors decreases our proprioception and balance and can lead to increase risk of falling and injury. This can be lost simply by wearing the all to common cushioned shoes many of us are wearing these days. Neurons thrive on stimulus among other things. More cushion means less stimulus and over time loss of sensory function.
Another important function is the arch of the foot for stability and support. Arches are great at resisting compressive forces. The shape of the arch allows for the force to distributed outward rather than straight down greatly increasing the amount of resistance the structure has. Arch of the foot supports the structure of the body. The muscles of the foot and the fascia that interconnects everything support this structure. Much of the tension is transferred to the fascia itself. However, modern footwear compromise this system. Arch supports and cushioning decreases the proprioceptive awareness interfering with mechanisms of the foot and arch. Without these signals the body has a difficult time responding to the signals. Great amounts of stress is placed upon the foot and everything above it.
Further complicating it, foot and ankle imbalances can often be asymptomatic. However, they can also cause secondary issues in the leg, knee, hip, spine, shoulders, and elsewhere.
The Wrong Shoe
Shoes have been around for thousands of years but only recently have they taken a drastic change. For many thousands of years, people wore sandals, simple leather shoes, or no shoes at all. Many people still do. I think of many of my friends in Africa. Many Africans grow up running around barefoot and it is a wonderful thing!
However, many of us spent most of our lives in a pair of shoes. Most of our shoes have a heel on them which causes us to tilt forward when standing resulting in compensations from the ground up. In addition to the heel the sole is often thick. In athletic shoes the entire sole especially the heel is heavily cushioned. It is marketed for the purposes of aiding in running so it is not so hard on the joints. Yet, our natural running gait is not a heel strike. When we walk the first part of our foot to touch the ground is our heel. But our gait changes when we run. We switch from a heel strike to a midfoot or forefoot strike. Watch anyone who is running barefoot. The mid to front part of the foot is the first to touch the ground. If you were to heel strike it would hurt!
The cushioning our shoes was to prevent that jarring effect but the problem is you shouldn’t even be running that way to begin with, it is not natural!
Our shoes are also very narrow especially in the toe box. Our toes are often squished and we often buy shoes smaller than we should. Our toes are meant to splay or spread to great a broader and more firm foundation. Our shoes limit our foundation, our movement, our proprioception, and our ability to adapt. Our environment does this too. Often times the only stimulus we have is a flat, hard surface like a sidewalk. How often are we walking on trails with rocky, uneven terrain? Which brings me to the next point.
What is natural?
As I stated our feet are designed to support the structure of the body that rests on top of it. That is a lot of weight. That is why we have an arch to distribute the downward force outward rather than straight down. The muscles, fascia, tendon, and ligaments all work together to form this arch. Furthermore, our toes are designed to spread creating a more firm foundation. A weakness in any one of these areas creates a weak link in the chain resulting in being more prone to injury. Stimulation of the mechanoreceptors allowing for maximal sensitivity helps maintain an awareness of foot position. Being barefoot is incredibly helpful in this regard or using a barefoot style shoe.
Barefoot shoes have a wide toe box for maximal toe splay. They are very flexible being able to roll into a ball basically. They are zero drop. What that means, is that, there is no heel. Everything is flat without an arch support. Lastly, the sole is fairly thin. I have a pair of Vivobarefoot shoes which I love that have about a 2mm sole. I wear them all the time. Vivo is by far my favorite brand in regards to barefoot shoes. They are durable and comfortable. There are few other brands that are not bad as well such as Vibram, Xero Shoes, and Merrell’s barefoot styled shoes. Even for your kids, but the best thing would be to let them be barefoot and enjoy nature! The Foot Collective sells toe spreaders that can help restore the natural splay. They also sell shoes and provide helpful tips.
You may have to experiment to find one you like the most, but your feet will thank you. Now transitioning to a barefoot or minimalist shoe can be difficult. Take your time and do not over do it. You can injure yourself. One important aspect is your running gait will need to change which I will talk about later on. You may need to transition slowly getting a shoe with less of a heel and slowly reduce it. You may need to walk with shorter strides and slower. If it starts to hurt slow it down. I will provide quite a few resources including some recommended books. Everyone is different. But the barefoot challenge I will mention later on will help with that.
Exercise and movement
I love walking around barefoot. We have lots of trails near our home and as long as it is not too rocky or cold you will most likely see me barefoot. If you are going to start walking barefoot, take your time. Your feet will be tender and sensitive. They have not felt that much stimulus in a long time! Your skin is also soft so it will take time to toughen them. Take it slow and easy is the name of the game.
I workout barefoot too. Of course, this depends on your gym and what your doing possibly. But it makes the workout rather enjoyable. Now running is a different story.
Our natural running gait is different from our running gait. You’ll notice when you walk that you heel strike each time you take a step. In other words, your heel is the first thing to touch the ground as you step. Many of you may be saying to yourself that is the same gait for when you are running. Well if you have ever tried to run with a heel strike barefoot you know that it hurts pretty bad. It is a jarring motion with the force propelling you backwards as you hit the ground rather than forward. It actually works against you.
If you watch a barefoot runner you will notice that they do not heel strike but rather they land either on the midfoot or the forefoot. This is the natural running gait. The force propels you forward not backward. There are a couple of good websites that teach you how to do this. They are great resources! One is Natural Running Center ran by Dr. Mark Cucuzzella. It has excellent tutorials and videos. Another comes from none other than Harvard. This site is dedicated to the research of barefoot running. It is primarily ran by Dr. Daniel Lieberman, who has some fantastic research articles on barefoot running and evolutionary medicine.
I highly recommend visiting those sites if you are wanting to transition to barefoot running or barefoot in general. And by now I hope you do! At the end of the article I will few books that I recommend. They are very informative!
The Barefoot Challenge
Now for a challenge! So for 30 days I want you to do essentially 2 things, that is it!
1. Look for about 20 feet of gravel or rocks.
2. Walk on 20 feet of gravel or rocks, once per day for 30 days.
A couple of caveats.
*If find your feet are too sensitive and the rocks hurt a lot, try dirt, sand, or asphalt. But work towards walking on the rocks.
*It may be rather difficult at first. You may need to tip-toe or walk on your forefoot for the first little while. Your feet will be tender but that should go dissipate over the 30 days and you will feel less and less tenderness and pain. Just take it slow and easy.
That is the challenge! I hope you do it! If it becomes easy try something more difficult, otherwise keep it up after 30 days!
1. Born to Run by Christopher McDougall
2. Natural Born Heroes by Christopher McDougall
3. The Big Book of Health and Fitness by Philip Maffetone
4. Whole Body Barefoot by Katy Bowman