Anatomy of the cervical spine: implications for the upper limb tension test

A detailed investigation of the anatomy of the lower cervical nerves and associated structures was undertaken, as these structures would most likely be affected by any stresses generated in the nerves of the brachial plexus during the upper limb tension test (ULTT). The investigation used dissection of three adult human spines and histological sections of three cervical spines. The results support the hypothesis that the lower cervical nerves have a specialised anatomical arrangement which may protect them from forces generated in the upper limb and cervical spine by the ULTT. The fifth, sixth and seventh cervical nerves are securely attached to many structures as they emerge from the spinal cord to form the brachial plexus. Furthermore, the posterior longitudinal ligament anchors the nerve roots to the vertebral bodies and intervertebral discs. The results suggest that innervated structures other than neuromeningeal tissue may also need to be considered when evaluating a patient's positive ULTT response.