thoracolumbar fascia/aponeurosis

Introduction

An extensive fascial sheet that splits into 3 layers: posterior, middle & anterior.

• posterior & middle layers: surround erector spinae muscles
• middle & anterior layers: surround quadratus lumborum The lumbar part of this fascia extends between the 12th rib & the iliac crest, becomes thin & transparent where it covers the thoracic part of the deep muscles(serratus posterior superior) & is reinforced inferiorly by the latissimus dorsi & serratus posterior inferior muscles.

Attachment

laterally to the internal oblique & transversus abdominis muscles.

More general terms

• fascia (superficial/deep)

Additional terms

• iliacus muscle
• quadratus lumborum fascia

Component of

• abdominal wall