Influence of hospital bed height on kinematic parameters associated with patient falls during egress

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Publication Type thesis
School or College College of Engineering
Department Mechanical Engineering
Author Christman, Marissa
Title Influence of hospital bed height on kinematic parameters associated with patient falls during egress
Date 2015-03
Description Understanding the quantitative aspects of kinematic and temporal parameters in fall-prone populations in natural environments is important, particularly in settings replicating hospital environments where patients are often impaired and less familiarized with the layout. Studies indicate fall rates are much higher in these settings than in comparable community settings. The aim of this study was to determine how bed height and side rail presence/type influence fall risk when patients get out of bed unassisted. Seventy-nine older adults with mobility impairments performed an unconstrained sit-to-walk movement at three randomized bed heights representing low, medium, and high bed conditions. Three side rail conditions were also studied. Temporal and kinematic parameters were obtained from key sit-to-walk movement events using 3D motion capture and ground reaction forces. There was no evidence that the presence of side rails influenced kinematics. Temporal parameters proved to be most affected by bed heights, particularly in the low bed condition. Velocity and momentum parameters were less significantly affected between conditions. Participants appeared to use similar momentum strategies to rise and initiate gait but altered their timing in order to accommodate their balance deficits. This study supports the model that suggests increased impairment leads to slower movement event timing during sit-to-walk transition. This study did not support other findings that mediolateral kinematics were higher in those with greater impairments, nor did bed height alter any of these kinematics at any event. Participants had statistically significant higher forward velocities when initiating gait from the medium bed condition, and they had statistically significant lower posterior momenta when exiting the high bed condition. These could be indications of increased mobility and improved use of generated kinetic energy. These represent potentially favorable results in light of reducing fall risk. Medium bed height appeared to produce the least significant differences in parameters when compared to the two other bed heights. This implies the most flexibility to prioritize postural stability or postural mobility. Low bed heights generated particular problems by reducing fluid motion and creating more impediments to postural stability. This suggests that low bed heights may not reduce fall rates during bed exit.
Type Text
Publisher University of Utah
Subject Bed height; Biomechanics; Falls; Kinematics; Mobility; Stability
Dissertation Institution University of Utah
Dissertation Name Master of Science
Language eng
Rights Management Copyright © Marissa Christman 2015
Format Medium application/pdf
Format Extent 1,418,201 Bytes
Identifier etd3/id/3744
ARK ark:/87278/s66q55jr
Setname ir_etd
Date Created 2016-02-29
Date Modified 2017-06-14
ID 197295
Reference URL