Plexuses6 min read

The lumbar plexus

L1–L4 within the psoas major, projecting onto the anterior thigh.

Formation

The plexus forms within the substance of the psoas major and sends its branches out along the muscle's borders — iliohypogastric and ilioinguinal above, femoral laterally, obturator medially.

Surface path

Its cutaneous field runs from the lower abdominal wall across the inguinal line onto the anterior and medial thigh, continuing to the medial leg through the saphenous branch.

Related formulations

In the atlas

Lumbar region

Educational reference material. Nothing in the Knowledge Center is medical advice, and no therapeutic effect is claimed or implied.

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Related knowledge

Structures, formulations and documentation connected to this article.

Formulation

FormulationTLO DUOThoracolumbar transition concept for the mid-to-lower back application field.→FormulationPlexus Lumbalis DUOLumbar plexus concept covering the lower back and anterior thigh projection field.→FormulationPlexus Lumbosacralis DUOTransition concept for the lumbosacral field, where lumbar and sacral territories meet across the pelvic rim.→

Plexus

PlexusLumbar plexusLower back, inguinal line, anterior and medial thigh.→PlexusCervical plexusLateral neck, occipital scalp, periauricular field and clavicular line.→PlexusBrachial plexusSupraclavicular fossa, shoulder cap, arm, forearm and hand.→PlexusSacral plexusGluteal region, posterior thigh, leg, foot and perineum.→

Knowledge article

Knowledge articleReading peripheral nerve territoriesWhy peripheral nerve fields and dermatomes describe the same skin in two different languages.→Knowledge articleThe sacral plexusL4–S4 on the posterior pelvic wall, origin of the sciatic nerve.→