Lumbar spine

Last edited and medically reviewed by Alaric Steinmetz on 25.08.2026

Synonyms

LWS

ICD-11

The lumbar spine (LWS) is the caudal segment of the Spine between the thoracic spine and the Os sacrum. It typically consists of five vertebrae (L1-L5) and, due to its biomechanical properties, represents one of the most common sites of degenerative, traumatic, and neurosurgically relevant disorders.

Imaging

Röntgen der Lendenwirbelsäule ap — AP Darstellung der Lendenwirbelsäule mit fünf Lendenwirbelkörpern im AP Röntgenstrahlengang.

Lendenwirbelsäule laterales Röntgen — Darstellung der Lendenwirbelsäule mit fünf Lendenwirbelkörpern im lateralen Röntgenstrahlengang.

Biomechanics

The lumbar spine bears most of the axial body weight and enables:

Flexion
Extension
Lateral flexion
Limited rotation

The transitional regions, particularly the lumbosacral junction (LWK 5/SWK1), are exposed to high shear and compressive forces. This explains the high prevalence of degenerative changes.