Fascia is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches, stabilises, encloses, and separates muscles and other internal organs. It is classified by layer, as superficial fascia, deep fascia, and visceral or parietal fascia, or by its function and anatomical location.
Like ligaments and tendons, fascia is made up of fibrous connective tissue containing closely packed bundles of collagen fibers oriented in a wavy pattern parallel to the direction of pull. Fascia is consequently flexible and able to resist great unidirectional tension forces until the wavy pattern of fibers has been straightened out by the pulling force.
Fasciae are similar to ligaments and tendons as they have collagen as their major component. They differ in their location and function: ligaments join one bone to another bone, tendons join muscle to bone, and fasciae surround muscles and other structures.
Myofascial release focuses on deep fascia which is a layer of dense fibrous connective tissue that surrounds individual muscles, and divides groups of muscles into fascial compartments. It has a high density of elastin fibre that determines its extensibility or resilience. Deep fascia is richly supplied with sensory receptors. Examples of deep fascia are fascia lata, fascia cruris, brachial fascia, plantar fascia, thoracolumbar fascia and Buck’s fascia.
Fascia becomes important clinically when it loses stiffness, becomes too stiff or has decreased shearing ability. When inflammatory fasciitis or trauma causes fibrosis and adhesions, fascial tissue fails to differentiate the adjacent structures effectively. This can happen after surgery where the fascia has been incised and healing includes a scar that traverses the surrounding structures.