Transcript Poster Sum Int S Lei..

Seating Biomechanics and Comfort
T.R. Bush, M. Dainoff, S. Leitkam
Chair A
Objective
Chair B
This will be accomplished by comparing objective biomechanical factors such as body pressures,
body kinematics, and chair kinematics to the corresponding ratings of discomfort taken at set
intervals during the study. A correlation is expected because while the two chairs being used in the
study perform the same functions, they do so by kinematically differing approaches.
Upright
The goal of this study is to provide evidence that biomechanics and comfort can be correlated in the
area of office seating.
1. Subjects are trained in the functions, features, and use of
the two office chairs
2. Subjects are targeted with reflective markers and trained
in the use of the Shen Parsons Scale and the Bodymap,
used to rate discomfort
3. Subjects are then seated at a computer for an hour in
each chair and asked to rate their discomfort every ten
minutes.
4. Corresponding to each discomfort rating, at every 9th
minute, kinematic positions and interface pressures are
tracked using a motion capture system and a pressure
mat.
5. After 30 minutes in each chair, subjects are asked to
change their position from an upright posture to a reclined
posture, or vice versa
6. At the end of testing, at least 3 data sets have been
collected for each chair and position combination (Chair A
upright, Chair A reclined, Chair B upright, Chair B
reclined)
Reclined
Procedure
The four combinations of position and chair that were performed are shown above.
Also included as an inset is the seatback pressure display for each chair and position. Red
areas represent higher pressures.
Results
Prior to any in depth analysis, early results indicate the following general trends:
Analysis
Above: Subject seated in Chair B during
testing
Below: Same scene as viewed through
the motion capture system
Analysis of the discomfort data will be performed by Dr.
Dainoff at the University of Miami Ohio and the
biomechanical data will be evaluated by the Biomechanical
Design and Research Lab at Michigan State University. The
two will then be compared for any correlations.
•Higher localized pressures are experienced between the seat back and user
in Chair B than in Chair A
•Most subjects prefer Chair A over Chair B when asked subjectively
Comprehensive results will be available after the kinematic, pressure, and
comfort analyses have been completed and compared.
Study generously funded by Steelcase Inc.
IRB # 06-764