Anatomy 101: Foot & Ankle
Last time I tried this this became a medical paper. So, I am going to keep this as simple as possible. It will be a challenge to say the least. This is how we are going to do this.
The first section is going to compromise of anatomical structure such as bones, and the second section is going to compromise of the muscles surrounding those bones. Just bear with me this will all come into play at the end of the month when we see how ankle movement during a squat is so important as to what happens at the foot and ankle. OK, let’s get on with it.
Section 1: Bone Structure
The basic structure of foot is made up of the fore foot, mid-foot and hind foot. There is a lot so bear with me.
The Forefoot is made up of the Metatarsals, and Phalanges
The mid foot is made up of 3 Cuneiform bones (Lateral, Medial, and Intermediate), the Navicular bone, and the Cuboid
The hind foot is made up of 2 bones, the calcaneus, and the talus
In total we are looking at about 26 bones in each foot. And we are going to briefly look at them and what they do.
The Calcaneus, this is the hardest bone in our bodies. It must be. It takes all the forces that come down from our bodies and distributes them either to the forefoot or the ground for traction. The image below shows perfectly how the calcaneus is designed. All the “grooves” or “smooth looking surfaces” are where the talus sits on. This is important as this is how the forces are distributed from the body to the foot and ground, as stated before.
The Talus, this bone is the largest in the ankle it is cradled by the fibula and tibia (the two bones that make up the shin), it “sits” on the calcaneal bone (Heel bone mentioned above). This bone is made up of three sections, the head, neck and body. The talus connects the ankle to the foot by two surfaces that connect to the navicular and the first two metatarsals (toe bones)
The Cuneiform Bones, these bones make up most of the mid foot they are compromised of the lateral, intermediate, and medial cuneiform bones. The medial Cuneiform bone leads to the big toe, the intermediate cuneiform bone lead to the second toe, and the lateral cuneiform bone transfers load to mostly the third toe but also some goes to the second toe. These bones are cradled by the navicular bone, but the lateral cuneiform bone also takes load from the cuboid as well.
The Navicular, this bone takes forces from talus and distributes those forces to the toes via the cuneiform bones stated above.
The Cuboid, this bone sits on the inside of the foot, it is positioned in between the second last toe and the pinky toe and connects to the calcaneus bone. It is designed to even out the forces being placed on the heel.
The metatarsals, these are five in total they take the forces from the midfoot and transfer them to the toes (or Phalanges). You can easily find them right behind the toes on our feet just run your hand across the top of your feet and you can feel each bone
The Phalanges, these are 14 in total that are divided into three sub sections. You have the proximal phalanx that are made up of 5 bones that connect the metatarsals to the intermediate phalanges, and the five intermediate phalanges are connected from the proximal to the distal phalanges that make up the toes. The one exception is the big toe, the big toe does not have a middle phalanx.
And there you go a brief overview of the structure of the foot and ankle. In the next section we are going to look at the muscles that make this complex piece of engineering move.
Section 2: Muscles of the Ankle and Foot
This section we are going to dive into the more complex part of the foot and ankle. The things that make it move. There are 18 in total and all are important if we are to understand what makes it work, and if one isn’t “pulling its weight” how the rest of the chain up the body can be affected. It all starts just under the knee. So, let’s dive into it.
Above is a brief look at all the muscles that make up the foot and ankle. I will do my best with whatever knowledge I have to briefly explain them without making this a medical paper.
So, let’s break this down to the four views that are available to us front, back, up, and down.
The Front View, if we look at the foot from the front we can see:
- Fibularis (Peroneus) Longus, which everts (turn out), dorsi flex (pulls up), and flexes the big toe,
- Tibialus Anterior, which inverts (turns in), dorsi flexes (pulls up) the foot,
- Extensor Digitorum Longus, this muscle passes down in front of the talus and spans out across the last four toes helping in toe flexion
- Fibularis (Peroneus) Brevis, which lies underneath the Peroneus Longus and allows the foot to plantar flex (point your toes) and eversion.
- Extensor Hallicus Longus, helps extend he big toe and dorsi flexes the ankle
- Extensor Digitorum Brevis, extends the metatarsal-phalangeal of the first to the fourth digits (toes)
The Back View, if we look at the foot and ankle from the back we can see:
- Gastrocnemius, the calve muscle, this muscle plantar flexes the foot
- Soleus, also plantar flexes the foot
- Plantaris, located inside the knee, plantar flexes the foot and aids in knee flexion
- Popliteus, internally rotates the tibia in relation to the femur (thigh bone), and unlocks the knee during knee flexion
- Extensor Digitorum and Hallicus Brevis Group, extends the toes
- Tibialis Posterior, this is the principal inverter of the foot, it also adducts, and plantar flexes the ankle, and aid in supination of the foot (rotates the foot up)
- Flexor Digitorum Longus, flexes toes 2 - 5 and helps plantar flex the ankle
- Flexor Hallicus Longus, flexes the big toe, helps supinate the ankle, and is a weak plantar flexor of the ankle
The top and bottom view of the foot are pretty much the same as the front and back part of the shins, with the only difference is the muscles that control the metatarsals such as:
- Flexor Digitorum Brevis, which flexes the toes
- Adductor Hallicus, Adducts the big toe
- Abductor Digiti Brevis, abducts the small toe
- Quadratus Plantae, helps flex distal phalanges
- Lumbricals, flexes metatarsophalangeals and extends interphalangeal
- Flexor Hallicus Brevis, flexes big toe
- Adductor Hallicus, Adducts big toe
- Flexor Digiti Minimi Brevis, flexes small toe
- Plantar Interossei, Adducts toes
- Dorsal Interossei, Abducts metatarsophalangeal joints
Phew that is it! One of the most complicated parts of the body and I hope I didn’t lose you guys, but you need to understand that if one of these muscles doesn’t understand when to fire at the right moment you will not be able to lift the most amount as you are capable and you will be limited in your result.
Next week, we are going to look into Ankle Sprains and we will be referring to this blog post for the rest of the month, don’t worry I will br setting links back to it. So, happy digesting.