title: Body height change during upright and recumbent posture.
abstract: Body height changes are known to occur in response to changes in loads acting along the spine, such as those produced by movement from a recumbent to an upright posture. Lack of previously available data is addressed here by body height measurements closely spaced in time of ten normal subjects during 8 hours upright and 4 hours recumbent, with particular attention paid to the initial changes. Experimental errors are carefully defined and determined. A Kelvin-unit model is fitted to the mean data for each phase and confidence limits provided for the model equation parameters. Rapid height changes are shown to occur: 26% of the 8-hour loss occurred in the first hour upright, and 41% of the 4-hour recovery occurred in the first hour recumbent.
authors.affiliation: Department of Orthopaedics and Rehabilitation, Loskeletal Research Center, University of Vermont, Burlington.
authors.forename: M H
authors.initials: MH
authors.lastname: Krag
authors.forename: M C
authors.initials: MC
authors.lastname: Cohen
authors.forename: L D
authors.initials: LD
authors.lastname: Haugh
authors.forename: M H
authors.initials: MH
authors.lastname: Pope
mesh_terms: D000328:Adult; D000886:Anthropometry / Q000295:instrumentation; D001827:Body Height; D005260:Female; D006801:Humans; D008297:Male; D011187:Posture; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D013997:Time Factors