Redefining the Manual Wheelchair Stroke Cycle: Identification and Impact of Nonpropulsive Pushrim Contact
By Kwarciak, Andrew M.; Sisto, Sue Ann; Yarossi, Mathew; Price, Robert; Komaroff, Eugene; Boninger, Michael L.; Archives of Physical Medicine and Rehabilitation, Vol. 90, No. 1, pp. 20-26Publication Date: January 2009
Study undertaken to create a comprehensive definition of the manual wheelchair stroke cycle including its multiple periods of pushrim contact. Participants, 44 men and 10 women with chronic paraplegia, a mean age of 40.7 years, and a mean weight of 76.6 kilograms, were asked to propel their own wheelchairs on a roller system at a self-selected speed and at a target speed of 1.8 meters per second. The wheelchairs were fitted with SmartWheels measuring wheel angular position and velocity as well as three-dimensional forces and moments applied to the pushrim during propulsion. Total force on the pushrim was used to define pushrim contact, and positive axle moment was used to identify the included period of propulsive contact. During most strokes, periods of nonpropulsive contact existed before and after propulsive contact. Within these periods, braking moments were applied to the pushrim, resulting in power loss. Including nonpropulsive data decreased mean stroke moment and power. The magnitude and the angle over which braking moments and power loss occurred increased with wheel speed. Mean braking moment and power loss within the initial contact period were significantly related to stroke pattern. The authors conclude that the proposed definition of the stroke cycle provides a thorough and practical description of wheelchair propulsion. Study limitations and implications for clinical practice and future research are discussed.
Assistive Products Discussed: Published by: W.B. Saunders Company, a division of Elsevier Health Sciences (Website:http://us.elsevierhealth.com)
American Academy of Physical Medicine and Rehabilitation (Web Site: http://www.aapmr.org/ )
American Congress of Rehabilitation Medicine (Web Site: http://www.acrm.org )
This publication is included in the library of the National Rehabilitation Information Center (NARIC), accession number J56648
