Radio-functional analysis of the cervical spine using the Arlen method. A study of 699 subjects. Part Two: Paradoxical tilting of the atlas.
The authors describe a peculiar movement of the first cervical vertebra: the so-called paradoxical tilting of the atlas, which consists of extension in relation to McGregor's line during flexion of the cervical spine. This physiological phenomenon has already been reported by several authors. The purpose of this study was to determine the mean amplitude and frequency of paradoxical tilting of the atlas in subjects with no known cervical pathology and to evaluate some of the factors that may influence it. The younger the subject the more frequent and more ample this paradoxical tilting: it occurs very often before the age of 40 years and is present in more than 93% of subjects under 20. Its amplitude diminishes with age, until it is replaced by mobility in flexion.
Kraemer
M
M
Patris
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001270:Cervical Atlas / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000502:physiology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D013122:Spinal Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology*