Quadratus Lumborum

The quadratus lumborum or QL is a common cause of back pain which is to one side and comes on after lifting or twisting.

Origin

  • Posterior iliac crest.
  • Iliolumbar ligament.

Insertion

  • Twelfth rib.  
  • Transerve processes of L1-L4.  

Actions

  • Lateral flexion (side-bends) of the trunk.

Innervation

  • Ventral rami of the subcostal nerve.  
  • Lumbar nerves.

Daily uses

  • Bending sideways to pick something up.  

Example strengthening exercises

Related injuries

Related muscles