TY - JOUR

T1 - A comparison of methods to compute the point of force application in handrim wheelchair propulsion

T2 - A technical note

AU - Sabick, Michelle B.

AU - Zhao, Kristin D.

AU - An, Kai Nan

N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.

PY - 2001

Y1 - 2001

N2 - Several methods are available for computing the location of the point of force application (PFA) in manual wheelchair propulsion using kinetic data. We compared five different techniques for computing the PFA location in analysis of data from five wheelchair users propelling their own wheelchairs using their normal propulsion style. The effects of the assumptions used in the calculations on the resulting location of the PFA, handrim force and moment components, and mechanical efficiency (e) were quantified. When kinetic data were used to locate the PFA, the most consistent and stable results were obtained using the assumptions that components of the handrim moment about the anteriorly directed and vertically directed axes were negligible. Some assumptions led to unsolvable equations at points during the propulsion cycle, demonstrating that they were inappropriate. All PFA values calculated with kinetic data were unstable at the beginning and end of the propulsion phase. While differences exist due to individual technique, assuming handrim moment components about the anterior-posterior, vertical, and/or both axes resulted in the most representative results.

AB - Several methods are available for computing the location of the point of force application (PFA) in manual wheelchair propulsion using kinetic data. We compared five different techniques for computing the PFA location in analysis of data from five wheelchair users propelling their own wheelchairs using their normal propulsion style. The effects of the assumptions used in the calculations on the resulting location of the PFA, handrim force and moment components, and mechanical efficiency (e) were quantified. When kinetic data were used to locate the PFA, the most consistent and stable results were obtained using the assumptions that components of the handrim moment about the anteriorly directed and vertically directed axes were negligible. Some assumptions led to unsolvable equations at points during the propulsion cycle, demonstrating that they were inappropriate. All PFA values calculated with kinetic data were unstable at the beginning and end of the propulsion phase. While differences exist due to individual technique, assuming handrim moment components about the anterior-posterior, vertical, and/or both axes resulted in the most representative results.

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M3 - Article

C2 - 11322471

AN - SCOPUS:0035707767

VL - 38

SP - 57

EP - 68

JO - Journal of rehabilitation R&D

JF - Journal of rehabilitation R&D

SN - 0748-7711

IS - 1

ER -