The lumbar ALL is a broad, thick band firmly adherent to the anterior vertebral bodies and anterior anulus fibrosus. It resists lumbar extension and provides anterior tensioning of the disc during flexion loading. ALL disruption in severe hyperextension injuries allows anterior vertebral body distraction — a rare injury mechanism in lumbar trauma producing the extension-distraction fracture pattern.
| Origin | Anterior vertebral bodies from L1-L5 (continuation of the thoracic ALL) |
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| Insertion | Anterior sacral promontory |
| Actions | Resists lumbar hyperextension; limits anterior vertebral body separation; fuses to the anterior anulus fibrosus at each disc level |
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The ALL is preserved in posterior lumbar fusion approaches but must be cut in anterior lumbar interbody fusion (ALIF) — removal of the ALL in ALIF allows disc distraction and indirect neural decompression. The ALL provides resistance to the distracting forces of ALIF cages, and its preservation in some approaches (oblique ALIF) provides anterior tension band stability.
ALL tearing in severe lumbar hyperextension producing anterior disc space distraction — a rare unstable pattern requiring surgical stabilisation.
