title: Kinematics of the lumbar spine in elderly subjects with decreased bone mineral density.
abstract: Lumbar spine kinematics was studied in subjects with normal bone mineral density, osteopenia and osteoporosis to determine the effect of bone mineral density and morphology on the flexion-extension movement patterns of the lumbar spine. Lateral radiographs and skin-mounted electromagnetic motion tracking sensors were employed to study lumbar spine kinematics using a Bayesian Belief Network model. The predicted angular displacement of the vertebrae had a high correlation (r = 0.91, p < 0.001) with the actual movements. The overall mean error was -0.51 degrees +/- 3.11 degrees. Intervertebral angular displacement and velocity consistently increased from L1/L2 to L5/S1. Differences were observed in the movement pattern between normal subjects and those with decreased bone density. In normal subjects, vertebral angular acceleration consistently decreased from the upper to the lower vertebrae but the same consistent predictable pattern was not observed in the subjects with decreased bone mineral density. It is possible that these changes in kinematic behaviours are related to morphological changes as well as altered neuromuscular functions.
authors.affiliation: Jockey Club Centre for Osteoporosis Care and Control, Public Health School, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Heather Ting
authors.initials: HT
authors.lastname: Ma
authors.forename: James F
authors.initials: JF
authors.lastname: Griffith
authors.forename: Zhengyi
authors.initials: Z
authors.lastname: Yang
authors.forename: Anthony Wai Leung
authors.initials: AW
authors.lastname: Kwok
authors.forename: Ping Chung
authors.initials: PC
authors.lastname: Leung
authors.forename: Raymond Y W
authors.initials: RY
authors.lastname: Lee
mesh_terms: D000368:Aged; D015519:Bone Density / Q000502:physiology; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging / Q000503:physiopathology; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology