Propulsion De Sillas

718

Propulsion Patterns and Pushrim Biomechanics in Manual
Wheelchair Propulsion
Michael L. Boninger, MD, Aaron L. Souza, MS, Rory A. Cooper, PhD, Shirley G. Fitzgerald, PhD,
Alicia M. Koontz, MS, ATP, Brian T. Fay, MS
ABSTRACT. Boninger ML, Souza AL, Cooper RA,
Fitzgerald SG, Koontz AM, Fay BT. Propulsion patterns and
pushrim biomechanics in manual wheelchair propulsion. Arch
Phys MedRehabil 2002;83:718-23.

© 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and
Rehabilitation

Objectives: To classify stroke patterns of manual wheelchair users and to determine if different patterns of propulsion
lead to different biomechanics.
Design: Case series.
Setting: Biomechanics laboratory.
Participants: Thirty-eightindividuals with paraplegia who
use manual wheelchairs for mobility.
Intervention: Subjects propelled their own wheelchair on a
dynamometer at 2 different steady state speeds. Bilateral biomechanical data were obtained by using a force and moment
sensing pushrim and a motion analysis system.
Main Outcome Measures: The propulsive stroke of each
participant for each speed and side was classified asfollowing
1 of 4 patterns. These 4 patterns were then compared by using
a mixed-model analysis of variance. The biomechanical variables that were compared were cadence, peak and rate of rise
of the resultant force, mechanical effective force, push angle,
and ratio of time spent pushing to time in recovery.
Results: The most common propulsive stroke involved the
user lifting the hand over thepushrim during the recovery
phase. The stroke pattern was independent of axle position and
varied from side to side and between speeds. After controlling
for subject characteristics, significant differences were observed between stroke patterns in cadence and ratio of time
spent pushing to time in recovery. A stroke pattern that involves using a semicircular motion with the hand below thepushrim during the recovery phase of the propulsion stroke was
associated with a lower cadence and more time spent in the
push phase relative to the recovery phase.
Conclusion: The semicircular motion of propulsion displayed characteristics consistent with reduced repetition and
more efficient propulsion. Use of this propulsion style may
reduce trauma to the upper extremities. Clinicians shouldconsider training individuals in this propulsion style.
Key Words: Biomechanics; Kinematics; Rehabilitation;
Wheelchairs.

WHEELCHAIR users (MWUs) are at a
M ANUALupper-extremity injury inThe mostiscommonlyhigh
risk of
injury.
reported site of musculoskeletal
MWUs the shoulder.

From the Departments of Physical Medicine and Rehabilitation (Boninger, Cooper)
and of Rehabilitation Scienceand Technology (Boninger, Souza, Cooper, Fitzgerald,
Koontz, Fay), University of Pittsburgh, and Human Engineering Research Laboratories, A VA Center of Excellence, Highland Drive VA Medical Center, (Boninger,
Souza, Cooper, Fitzgerald, Koontz, Fay) Pittsburgh, PA.
Supported by the National Center for Medical Rehabilitation Research, National
Institutes of Health (grant no. 5 P01 HD33989 01),US Department of Veterans
Affairs Rehabilitation Research & Development Services (project no. B2290T), and
the Paralyzed Veterans of America.
No commercial party having a direct financial interest in the results of the research
supporting this article has or will confer a benefit upon the authors(s) or upon any
organization with which the author(s) is/are associated.
Reprint requests to MichaelL. Boninger, MD, VA Pittsburgh Healthcare System
151R-1, 7180 Highland Dr, Pittsburgh, PA 15206.
0003-9993/02/8305-6890$35.00/0
doi:10.1053/apmr.2002.32455

Arch Phys Med Rehabil Vol 83, May 2002

Surveys of MWUs show the prevalence of shoulder pain to be
between 31% and 73%.1-5 The most common neurologic cause
of upper-extremity pain in MWUs is carpal tunnel syndrome,
with a...