title: The R-zero line: a new kinematic concept of the lumbar spine.
abstract: A new kinematic concept is described that relates to the notion that the lumbar spine behaves as a complete structure. This concept is called the "R-zero line" and represents kinematically the neutral position of the lumbar spine between anteflexion and retroflexion. The clinical significance of this parameter is evaluated in normal individuals and in patients with a symptomatic herniated disc at L4-5, with a symptomatic herniated disc at L5-S1, and with spondylolysis/spondylolisthesis. The results of this study show that the R-zero line has a characteristic configuration in all four test groups.
authors.affiliation: Department of Neurosurgery, De Wever Hospital, NL-6401 CX Heerlen, The Netherlands.
authors.forename: M W
authors.initials: MW
authors.lastname: Berfelo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000503:physiopathology; D016014:Linear Models; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D012044:Regression Analysis; D013131:Spine / Q000000981:diagnostic imaging* / Q000502:physiology*; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000503:physiopathology; D013169:Spondylolysis / Q000000981:diagnostic imaging / Q000503:physiopathology; D055815:Young Adult