title: A kinetic analysis of manual wheelchair propulsion during start-up on select indoor and outdoor surfaces.
abstract: The objective of this study was to conduct a kinetic analysis of manual wheelchair propulsion during start-up on select indoor and outdoor surfaces. Eleven manual wheelchairs were fitted with a SMART(Wheel) and their users were asked to push on a course consisting of high- and low-pile carpet, indoor tile, interlocking concrete pavers, smooth level concrete, grass, hardwood flooring, and a sidewalk with a 5-degree grade. Peak resultant force, wheel torque, mechanical effective force, and maximum resultant force rate of rise were analyzed during start-up for each surface and normalized relative to their steady-state values on the smooth level concrete. Additional variables included peak velocity, distance traveled, and number of strokes in the first 5 s of the trial. We compared biomechanical data between surfaces using repeated-measures mixed models and paired comparisons with a Bonferroni adjustment. Applied resultant force (p = 0.0154), wheel torque (p < 0.0001), and mechanical effective force (p = 0.0047) were significantly different between surfaces. The kinetic values for grass, interlocking pavers, and ramp ascent were typically higher compared with tile, wood, smooth level concrete, and high- and low-pile carpet. Users were found to travel shorter distances up the ramp and across grass (p < 0.0025) and had a higher stroke count on the ramp (p = 0.0124). While peak velocity was not statistically different, average velocity was slower for the ramp and grass, which indicates greater wheelchair/user deceleration between strokes. The differences noted between surfaces highlight the importance of evaluating wheelchair propulsion ability over a range of surfaces.
authors.affiliation: Human Engineering Research Laboratories, Department of Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA 15206, USA. akoontz@pitt.edu
authors.forename: Alicia M
authors.initials: AM
authors.lastname: Koontz
authors.forename: Rory A
authors.initials: RA
authors.lastname: Cooper
authors.forename: Michael L
authors.initials: ML
authors.lastname: Boninger
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Yang
authors.forename: Bradley G
authors.initials: BG
authors.lastname: Impink
authors.forename: Lucas H V
authors.initials: LH
authors.lastname: van der Woude
mesh_terms: D000328:Adult; D000671:Amputation, Surgical / Q000534:rehabilitation; D001107:Architectural Accessibility; D004867:Equipment Design; D016552:Ergometry; D005260:Female; D005430:Floors and Floorcoverings / Q000145:classification*; D006801:Humans; D007700:Kinetics; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000534:rehabilitation; D013119:Spinal Cord Injuries / Q000534:rehabilitation; D013499:Surface Properties; D019415:Torque; D014910:Wheelchairs