On my blog, I want to presenting anatomy lessons which I am sharing with the Yoga Teacher Training at Yoga Vermont. I put together short little lessons with some experiences to explore, which then make a perfect link to my blog. So here goes the first one.
KEYNOTES ON THE FOOT:
Here are some fun openers: one quarter of the bones in your body are in your feet. It makes sense when you think how versatile they are. Each foot has 26 bones, 32 joints, 56 ligaments and 38 muscles.
A nice pattern trickles down from the femur, the thigh bone, of 1,2,3,4,5 in groups. There is 1 femur, there are 2 tibia and fibula (shin bones), 3 bones in the ankle joint (the calcaneus, talus and nevicular, 4 cuniform and cuboid( proximal transverse arch), 5 metatarsals (distal transverse arch) and 5 tarsals (toes).
The foot is assigned the destiny of traversing swiftly between stability and mobility at our whim. There are places in it’s structure that create limitations and increase stability and there are places that are very dynamic, mobile and when not appreciated, can become weak and unsupported, not stable enough. What is helpful to know is that awareness of how things work together is essential if you want to have a dynamic, alive and healthy body as long as you are in it.
The calcaneus, (heel bone) is a beautiful bone. It is solid, grounding deeply back behind the center of the ankle and then rising up the beginning of one-third of the length span arch of the foot, like the beginning of a wave. At it’s crest, from above, sits a three sided bone, the Talus, that is rounded at the top, like a bald head for the tall hat of the tibia, with the fibula attaching along side. Directly beneath, it sits like a hat on the calcaneus. So it is a hat with a hat upon it. Along the front, it is rounded into the navicular. No ligaments attached to it, so it is like a ball baring (pronation and supination).
Just past the navicular bone is the proximal transverse arch, which spans across the foot. This is where we wobble when we balance. It is a sturdy arch, like a roman arch, where the bones are wider on top then on the bottem, built to sustain the complete weight of the body on one foot. Yet a bit lower down, at the distal transverse arch, it is more weak and movable. The bones are rounded and supported more muscularly underneath then with bone structure, which begs for our understanding of usage. The gift it gives us the ability to mold around a boulder when we hike, or a branch, when we climb a tree, or to catch ourselves when we misstep off a curb. Since many of us don’t engage in these activities often, but rather traverse primarily along flat surfaces, this arch is prone to collapse regularly, causing us to shift our weight medially (inward) or laterally (outwardly), most often medially. How the weight is distributed through these arches effects the entire navigation of the distribution of weight through joints along the whole body. Our knees, hips and spine can be affected by the lack of symmetry in the transverse arches. Even our bones can bend to accommodate the weakness.
As you read on, you will see that this is like a puzzle. There are a few interesting pieces to be put together. The Longitudianl arch – the calcaneus, the cuboid and the forth and fifth metatarsals and tarsals on the lateral side of the foot – is very stable as the cuboid bone also is wider on top and more narrow on the bottom, like a sturdy roman arch. But full effective movement combined with stability often requires a contralateral patterns, like an “X”. The lateral foot is very equipped to hold weight. But above it, the lateral leg that directs it’s force upon the lateral arch, is just a spindelly narrow bone, the fibula, that holds no weight from the body above. So what is the other side of the “X”?
Here is the rub. The Medial arch – the talus, the navicular, the three cuniforms and the first three metatarsals and tarsals – is more mobile ad less stable. Above the talus, remember, is the great towering tall hat, the Tibia, which holds above it, the femur, the pelvis, the spine, the arms and the head. Here is the facts about the design and why: The first cuniform, most medial, is slightly wider on the bottom, which, points to mobility that helps with the need of the body to ossilate as it attempts to balance and be ready to move instantly into a new position when called to. So, with a lack of understanding, it falls, as is often the case, under it’s towering weight.
Here is the keystone, the other side of the “X”! The Talus sits on a small ridge of the calcaneus called the sustentaculum tali that juts medially from the main body of the calcaneus. So the weight from the Tibia is distributed across, through the calcaneus and the lateral arch, like an outrigger, creating support. The heel, it is described by Thomas Myers, holds the ankle bone, like a waiter holds a tray. Transferring the need of support to the outrigger, allowing the medial arch to be more mobile and dexterous, aiding ins it’s gifts of propulsion,.
A FEW MORE FACTS:
Beneath these arches, is more support. The bodies design gives us many tools. the ligamentus and fascial webbing that sustains the arch from below is called the Plantar fascia. It is a Bowstring to the bow of the bones. Each time weight comes down, the heel and the ball separate. The arch would collapse if it were not for the plantar fascia. And from above to below, are the muscles of the calf. There is a sling that creates primary support for the medial arch. The meaty tibialus anterior runs from just below the knee, down to the ankle, across and under the medial arch. It attaches to the first cuniform and the first metatarsal deep into the ligamentus bed and the periosteum, which indicates that it’s support is significantly strong). Down the entire shaft of the fibula, on the lateral side of the lower leg, is the Fibularis Longus. It drops behind the lateral maleolus )nub of the ankle), and dives deep, to the periosteum and ligamantal bed to lateral side of first cuiform and first metatarsal. So, like two hands holding the foot from each side, these muscles are like reins of a horse, they can go lateral or medial. We want them to be in balance, equal
Also, the Tibialus Posterior runs deep along the back of the calf, the interossius membrane, to the medial malleolus to grab with several fingers, the medial arch. It creates another sling, though slightly different with the fibularis longus And finally the Peroneus Brevis: Pulls the fifth metatarsal firmly into the cuboid, supporting the lateral arch.
If you trace these muscles along your calf and foot an imagine how they can grab, you will get an idea of their support. Look at an anatomy book to get an idea of how all these bones and muscles look and bring it into your play and you will begin to know more about your body. The sources of this writing is: The Body3, by Thomas Myers and The New Rules of Posture, by Mary Bond. Thank you for reading.