What is the plantar fascia of the foot?

Plantar Fascia Anatomy
The plantar fascia is a structure made of a thick band of fibrous connective tissue on the sole of the foot that connects the forefoot to the heel. More precisely it connects the Calcaneus (heel bone) to the Metatarsal bones.
The plantar fascia inserts at 3 locations, in the forefoot, creating 3 bands: medial, central, and lateral.
The central band is the thickest and strongest – this band is usually implicated in PF. The central band divides into 5 separate bands, with each band attaching to one of the proximal phalanges (toe bones).
Plantar Fascia Function
The plantar fascia plays a significant role in walking, by supporting the arch. As your heel hits the ground at the beginning of your step, your plantar fascia is rapidly stretched. The plantar fascia is put under increasing tension and acts as a pressure absorber while supporting the foot bones above it.
One biomechanical model suggested it carries 14% of the foot’s stress. As you keep moving forward the heel lifts and the plantar fascia recoils as the tension is released.
When it becomes damaged
When the plantar fascia becomes irritated, torn, or damaged, it can result in plantar fasciitis (pain at the bottom of your heel and arch). Read this helpful, medically reviewed article about plantar fasciitis to learn more about the causes, symptoms, and treatment of this condition.
References
Plantar heel pain (2013) https://doi.org/10.1016/j.mcna.2013.10.009
Resources to help you visualize the plantar fascia anatomy
Human anatomy and physiology course taught by Dr. James Ross: https://www.humananatomycourse.com/