Insight into understanding the anatomical and clinical aspects of supernumerary rectus capitis posterior muscles

Abstract

Rectus capitis posterior muscles are located in the suboccipital triangle and function in extension and lateral rotation of the head and neck. There are two of these muscles on each side: the rectus capitis posterior major and the rectus capitis posterior minor. This study describes the presence of a third suboccipital muscle in a 55-year-old cadaver. In addition to highlighting the possible relationship between these muscles and cervicogenic headaches or balance in an individual, we also relate this observation to similar musculature in the cat that have been shown to effect crucial functions.

The myodural bridge in the common rock pigeon (Columbia livia): Morphology and possible physiological implications

“…Conservation of the myodural bridge across the different species of terrestrial vertebrates (sauropsids and mammals) may indicate the functional importance of the myodural bridge. The myodural bridge has been considered to anchor the dura mater, thus, preventing its buckling (Hack et al, 1995; Shinomiya, Dawson, Spengler, Konrad, & Blumenkopf, ; Tagil, Ozçakar, & Bozkurt, ; Scali et al, ).…”

Connection of the Posterior Occipital Muscle and Dura Mater of the Siamese Crocodile

“…These studies suggest that the human myodural bridge is the connective tissue bridge between deep structures in the suboccipital region and dura mater. The myodural bridge in the epidural cavity is formed from the rectus capitis posterior minor, the rectus capitis posterior major, obliquus capitis inferior and the nuchal ligament and inserted to the dura mater (Khan and Kortiké, ; Hack et al, ; Tagil et al, ; Scali et al, ,b; Pontell et al, ). Many mammals, including the monkey, dog and cowfish, were investigated by our research team and a myodural bridge was found in each of them (unpublished findings).…”

“…Relevant reports in recent years have suggested that the myodural bridge has important pathophysiological functions. Myodural bridges might generally play a role in protecting the spinal cord from dural enfolding (Hack et al, ; Alix & Bates, ; Nash et al, ; Tagil et al, ; Scali et al, ; Pontell et al, ), by placing the dura under tension (Alix & Bates, ; Scali et al, ,b; Pontell et al, ), and also aid in the maintenance of CSF outflow from the cisterna magna (Scali et al, ,b; Pontell et al, ) by maintaining the integrity of the subarachnoid space. Sui et al () and Zheng et al () proposed that the suboccipital muscles‐myodural bridge‐cervical dural sleeve complex was most likely acting as a pump to provide power for cerebrospinal fluid (CSF) circulation.…”

Back Muscles

“…It has been reported that doubling or division of the rectus muscles is rather common, but quite rare for the oblique muscles (Tagil et al 2005;Standring 2009). It has been reported that doubling or division of the rectus muscles is rather common, but quite rare for the oblique muscles (Tagil et al 2005;Standring 2009).…”