Back Muscles


thrombos major, thrombos minor (extrinsic group),
Muscle Groups: flexion (bilateral)-muscles anterior to the spine, rectus abdominis and psaos major

extension (bilateral)-muscles posterior to the spine, erector spinae

bilaterally mean both have to contract together to perform action
rotation (unilateral)-muscles with oblique fibre orientation, external oblique, internal oblique(opposite side) and erector spinae

lateral flexion (unilateral)-erector spinae, external and internal oblique

Anterior Abdominal Wall Muscles
-3 large and flat muscles with different fibre orientation
-rectus abdominis
-anterior flexion, lateral flexion and rotation if the trunk

Posterior Abdominal Wall Muscles
-3 main muscles: illiacus, psoas major, quadratus lumborum
-anterior flexion (psoas) and lateral flexion of the spine


split into three columns which form erector spinae
Clinical Anatomy of the Back

