L4-L5
Medical abbreviation · Anatomy
| Stands for | Fourth and fifth lumbar vertebrae (intervertebral level) |
|---|---|
| Categories | Medical |
L4-L5 stands for Fourth and fifth lumbar vertebrae (intervertebral level), an anatomy abbreviation.
Lumbar segment carrying heavy loads and frequent motion, one of the two most common levels for disc herniation, spinal stenosis and degenerative spondylolisthesis. A typical posterolateral L4-L5 herniation compresses the L5 nerve root, causing pain down the side of the leg and weakness lifting the big toe or foot.
Example: L4-L5 herniation with L5 radiculopathy and EHL weakness; PT and epidural injection planned.
Usage notes
The L5 root controls ankle dorsiflexion and big toe extension, so severe compression can cause foot drop. Degenerative slipping of L4 forward on L5 is especially common in older women. Lumbar punctures are often performed at this interspace, found near the line joining the tops of the iliac crests (Tuffier line).
Related abbreviations
More anatomy abbreviations
- ICA – Internal carotid artery
- ICS – Intercostal space
- IJ – Internal jugular (vein)
- IMA – Inferior mesenteric artery
- IT band – Iliotibial band
- L-spine – Lumbar spine
- L5-S1 – Fifth lumbar and first sacral vertebrae (lumbosacral junction)
- LCL – Lateral collateral ligament
- LE – Lower extremity
- LLQ – Left lower quadrant
- LN – Lymph node
- LUQ – Left upper quadrant
See all 70 anatomy abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.