The ligamentum nuchae is the expanded supraspinous ligament equivalent of the cervical spine, forming a broad fibrous septum between the occiput and C7. In humans it is a condensed fibrous sheet rather than the powerful elastic ligament of quadrupeds. It provides attachment for the trapezius and other posterior cervical muscles and contains a high density of sensory mechanoreceptors contributing to cervical proprioception.
| Origin | External occipital protuberance and median nuchal line of the occipital bone |
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| Insertion | Bifid spinous processes of C2-C7 — the ligamentum nuchae is a fibrous septum (not a simple cord) separating the posterior cervical muscles bilaterally |
| Actions | Resists cervical flexion; provides attachment for the posterior cervical muscles; in quadrupeds it is the primary head support structure but in humans it is vestigial functionally |
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The ligamentum nuchae is visualised on MRI as a low-signal midline structure in the posterior cervical soft tissues. Oedema or disruption within it on MRI after whiplash indicates posterior ligamentous complex injury. Calcification of the nuchae ligament (ossification) is a normal ageing variant that should not be confused with pathology.
MRI signal change in the ligamentum nuchae after hyperflexion injury indicating posterior cervical ligament complex involvement.
