Healthcare Design - January/February 2016 - 48

R RESEARCH | 02.16
A new view on patient falls

Designing environments to prevent patient falls is especially challenging since so many
incidents aren't actually witnessed. One research team decided to change that
By Debajyoti Pati
The effect of patient falls is far-reaching. Falls
are the leading cause of injury and account for
6.5 percent of reported sentinel events in hospitals, with a direct medical cost of $34 billion
annually, according to the Centers for Disease
Control and Prevention. While healthcare stakeholders generally agree that the physical design
of a space contributes to patient falls, there's
little understanding of the specific role design
plays. After all, how could one definitively
identify physical environment attributes without

entities, humans are also physical entities,
which means their physical activities involve
forces inside the body. The human body
consists of physical matter, and all physical
actions are subject to physical forces (gravity, friction, etc.). The human body, like all
physical objects, also has a center of mass
that constantly accelerates and decelerates,
unless one is in a resting position. Observation of a consistent increase in what's known
as the "jerk trajectory" of the center of mass

witnessing an actual fall event in context?
We know that there are two kinds of factors
that contribute to falls: intrinsic and extrinsic.
Intrinsic factors consist of one's physical,
mental, and physiological state, including age,
gender, influence of medication, visual impairment, psychological condition, etc. The physical environment is a type of extrinsic factor.
According to a 2011 study by T.P. Haines
and N.G. Waldron in the Journal of Safety Research, more than 70 percent of patient falls
are unwitnessed, which renders understanding of the role of the physical design largely
impossible. The only tools available to the
designer are educated guesswork and a few
broad-brush correlational studies, including
the 2012 study "Contribution of the Designed
Environment to Fall Risk in Hospitals" by
Margaret Calkins, Stacey Biddle, and Orion
Biesan for The Center for Health Design-a
report that was used as a foundation for a
more recent look at the issue. That study examined archival data from 27 inpatient units in
12 hospitals to identify associations between
frequency of fall events and a range of physical design factors. The current study focused
on some of the factors showing significant
differences.

indicates the beginning of a fall, according
to engineering theories. Jerk represents the
rate of change in acceleration of the center of
mass with respect to time, or the smoothness
of a movement.

Theory in action
Armed with a grant from the National Patient
Study Foundation in 2013, the study team (the
author of this article along with James Yang
of the Texas Tech University department of
mechanical engineering) decided to view fall
phenomena from a biomechanical perspective.
Although social, cultural, and psychological
48

HCDmagazine.com 02.16

More than 70 percent of patient falls are
unwitnessed, which renders understanding of
the role of space design largely impossible.
To study this theory in action, 30 elderly
subjects were asked to follow a scripted list
of tasks inside a clinician zone and bathroom constructed as part of a patient room
mock-up at the Human-Centric Design Research Lab at Texas Tech (Lubbock, Texas).
There were a total of 600 trials, and the
script was developed by the falls committee of Covenant Health System in Lubbock.
The physical mock-up was based on an
extensive review of patient room designs
in the archives of HKS Inc. (Dallas). The
experiments included variations in bathroom
locations, door locations, door swing, and
which hand was attached to IV tubing with a
mobile pole.
Motion capture technology, in combination with software specializing in identification of core of mass and calculation of jerk
trajectory, helped identify the trajectory of
the center of mass for each individual subject as well as the moment representing the
initiation of fall. Actual falls were prevented
by building a harness to which all subjects
were attached continuously during the trials. The harness works like a car seat belt,

Debajyoti Pati

http://www.HCDmagazine.com

Healthcare Design - January/February 2016

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