Hello! Shorty here to teach you a little bit about your foot. Today's focus is the Calcaneus!
Your calcaneus (aka your heel bone) is not just a round nub at the end of your lower leg. It extends behind your two lower leg bones and forward towards the center of the arch of your foot. Your talus sits above your calcaneus and interacts with your tibia and fibula, the bones of your lower leg, which create the archway of your ankle. Let's talk about the calcaneus, learn where it is and what it does!
The terms "pronation" and "supenation" of the foot have to do with how your calcaneus sits and thus affects the function of the foot. A pronated foot is one that rolls in, collapsing the arch of the foot. A supinated foot rolls out, putting a lot of weight on the outside of the foot and causing the inner arch to pick up away from the ground more than it should.
Notice that in neutral, because your calcaneus is not a square, your weight does not fall in the center vertically (the arrows do not align perfectly). The calcaneus is constructed to have a bit more of its bony weight on the outside, leaving room for muscles, ligaments and tendons on the inside of the ankle. These support the medial longitudinal arch. In walking, your foot naturally moves through a slight supination and pronation.
You may know about your achilles tendon or have heard of plantar fasciitis. The achilles tendon wraps around the back of your calcaneus and your plantar fascia grows forward from the under side of your calcaneus, creating a sling around your heel. Often times when your gastrocnemius and/or soleus (aka your calves) get tight, this tightness affects tension under the sole of your foot in your plantar fascia. Your heel functions as the fulcrum to the muscles of your superficial back line. This fulcrum helps you propel yourself forward in walking and running as well as keeps the muscles of your calves and sole of the foot pulled long when you are standing still.
Your calcaneus not only receives gravity and the weight of your body, it also distributes it forward and backward through the feet. Your vertical plumb line falls more or less through the center of your calcaneus (front to back). It has the ability to shift inwards and outwards, adapting to the needs of your gait and balance. In order to have a well-functioning foot and ankle, your calcaneus has to be able to feel the floor and have mobility, stability and adaptability to deal with the varying surfaces of the ground and actions your body makes.
Stay tuned this week for new ways to feel and experience your heels as well as some exercises to balance them!
Did you enjoy this post? See more from our Month of the Foot series here!
See what else Shorty Swan has to say!