Lower back

Lower Back (Lumbar Muscles)

The lower back, or lumbar region, contains a large and complex group of muscles that work together to support the spine, help hold the body upright, and allow the trunk to move, twist, and bend. The main muscle groups include the extensors (e.g., erector spinae, quadratus lumborum, multifidi), flexors (e.g., psoas major), and obliques (internal and external obliques). These muscles attach to the lumbar vertebrae, pelvis, and ribs.

These muscles are vital for supporting the upper body's weight, distributing body weight, and transferring weight from the upper body to the legs. The extensors enable actions like standing and lifting objects and help bend the spine backward, while flexors facilitate bending forward and arching the lower back. The oblique muscles assist in spinal rotation and maintaining proper posture.