Okay everyone, you are going to get a real kick out of this video, because we're going to talk about the anatomy of the foot.
The foot can be divided into two main parts - the sole or plantar region, which is the part of the foot contacting the ground, and the dorsum of the foot or the dorsal region, which is the part directed superiorly.
Alternatively, it can be divided into three sections - the hindfoot, containing the talus and calcaneus; the midfoot, containing the navicular, cuboid, and cuneiforms; and the forefoot, which includes the metatarsals and phalanges.
The foot also has two important landmarks - the heel, which is the sole of the foot underlying the calcaneus, and the ball of the foot, which is the sole underlying the heads of the medial two metatarsals.
So let’s talk a bit about the foot’s components. The most superficial elements are skin and fascia, which vary in thickness and strength across the foot, depending on if the area has roles in weight-bearing, ground contact, or compartmentalization.
The skin on the dorsum of the foot is much thinner and less sensitive than the one on the sole. By contrast, the thick skin on the sole is ticklish, hairless, and has numerous sweat glands.
The fascia of the foot can be divided into superficial and deep fascia. The superficial fascia or the subcutaneous fat tissue is loose and deep to the dorsal skin.
It is much more fibrous in the sole and is thicker than in other areas of the foot, making the heel act as a shock absorbing pad.
The deep fascia of the dorsum of the foot is rather thin and continuous proximally with the inferior extensor retinaculum.
It is also continuous with the plantar fascia, the deep fascia of the sole, over the lateral and posterior aspects of the foot
Speaking of which, the plantar fascia on the plantar aspect of the foot helps protect the sole from injury, and supports the longitudinal arches of the foot.
It consists of a thick central part, called the plantar aponeurosis, and weaker medial and lateral parts.
The plantar aponeurosis is strong, because it consists mostly of longitudinal bundles of dense fibrous connective tissue that invests the central plantar muscles.
These longitudinal fibers originate as a single entity on the medial process of the tuberosity of the calcaneus, and as they move towards the toes, they divide into five bands that become continuous with the fibrous digital sheaths that enclose the flexor tendons that pass to the toes.