fascial

Fascia, in anatomical terms, refers to a band or sheet of connective tissue that encloses, supports, and separates muscles, muscle groups, vessels, nerves, and organs throughout the body. It forms a continuous three-dimensional network that extends from the head to the toes, helping to coordinate movement and maintain structural integrity across regions.

Fascia is primarily made of collagen fibers, especially types I and III, along with elastin, fibroblasts, and a hydrated ground substance. This composition allows fascia to be both strong and somewhat flexible, enabling sliding between adjacent layers while transmitting mechanical forces generated by muscles. Fascia is organized into layers with varying density: a superficial fascia beneath the skin that often contains fat and nerves, deep fascia which forms dense envelopes around muscles and neurovascular bundles, and visceral fascia that surrounds and supports internal organs.

Functions of fascia include compartmentalizing and stabilizing structures, transmitting and distributing forces during movement, allowing coordinated gliding between tissues, and housing sensory receptors that contribute to proprioception and nociception. Because fascia is interconnected, restrictions or adhesions in one region can influence movement and comfort elsewhere. Pathological changes—such as fibrosis, scarring, or dehydration—can contribute to stiffness and pain in some conditions.

Common examples of fascial structures include the plantar fascia of the foot, the fascia lata of the thigh, and the thoracolumbar fascia of the back. Etymologically, fascia derives from Latin and reflects its role as a band or layer within the body's connective tissue framework.