Sacral plexus

Anatomy

Course
Made up of the anterior rami of S1 – S4 and the lumbosacral trunk, which is made up of L4 and L5. It is a part of the lumbosacral plexus. It is in the pelvis, located just by the posterior pelvic wall, anterior to the piriformis muscle.

The anterior rami of spinal nerves S1-S4 and the lumbosacral trunk all join here together in different branching patterns to form a number of terminal branches such as the sciatic nerve (made up of fibres from L4-S3), the pudendal nerve (made up of fibres from S2-S4) and the superior gluteal nerve (made up of fibres from L4 – S1).

Supply

The terminal branches from the lumbosacral plexus, which the lumbar plexus is a part of, provide sensory and motor innervation to the lower half of the body.

Clinical

Damage to the lumbosacral plexus can have effects of varying severity. It will result in a motor or sensory deficit in the lower half of the body with possible pain, tingling or burning. In the most severe cases, damage can result in paralysis of the lower half of the body.

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