Thoracolumbar fascia

Fascia thoracolumbalis · Hrudobederní fascie

Fascia & connective tissue

Looks like

A broad diamond of tough sheet over the low back, tying the arms to the opposite leg.

Transfers force across the back and gives the deep muscles something to pull on.

Move in all directions; it stiffens with long sitting and is often what feels tight in back pain.