The Myodural Bridge
‘What a name! I was always intrigued by the difference between a group of patients who could quite easily elongate their upper cervical extensor muscles (“pull your chin in”) and another group where upper cervical flexion was particularly sensitive and easily evoked HEADACHE. The repeated clinical anecdote is that the second group can flex their upper cervical spines more easily in sitting or even better, in supine with their knees flexed. This may well unload the myodural bridge.
Myodural bridges are connections between the cervical dura mater and the cervical extensor muscles. These connections probably anchor the dura and stop it folding in on the cord when you look up and extend your head back (Hack et al 1995, Rutten et al. 1997). This may have been an evolutionary advantage to our ancestors as they gazed up in awe at the firmament! There is a great recent review out by Enix et al (2014), updating the anatomy of the bridges including sub occipital bridges and proposing clinical implications. Think of it next time you are having a look at a patient’s posture as they sit in front of you with their worries and concerns? or ask someone to tuck their chin in. It also remind us that everything is kind of joined up in the body; discrete anatomy is for the textbooks.‘ David Butler NOI notes July 2014
Enix DE et al (2014) The cervical myodural bridge, a review of literature and clinical implications. J Can Chiropr Assoc 58: 184