title: Differentiation between solid-ankle cushioned heel and energy storage and return prosthetic foot based on step-to-step transition cost.
abstract: Decreased push-off power by the prosthetic foot and inadequate roll-over shape of the foot have been shown to increase the energy dissipated during the step-to-step transition in human walking. The aim of this study was to determine whether energy storage and return (ESAR) feet are able to reduce the mechanical energy dissipated during the step-to-step transition. Fifteen males with a unilateral lower-limb amputation walked with their prescribed ESAR foot (Vari-Flex, Ossur; Reykjavik, Iceland) and with a solid-ankle cushioned heel foot (SACH) (1D10, Ottobock; Duderstadt, Germany), while ground reaction forces and kinematics were recorded. The positive mechanical work on the center of mass performed by the trailing prosthetic limb was larger (33%, p = 0.01) and the negative work performed by the leading intact limb was lower (13%, p = 0.04) when walking with the ESAR foot compared with the SACH foot. The reduced step-to-step transition cost coincided with a higher mechanical push-off power generated by the ESAR foot and an extended forward progression of the center of pressure under the prosthetic ESAR foot. Results can explain the proposed improvement in walking economy with this kind of energy storing and return prosthetic foot.
authors: Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, the Netherlands; Department of Research and Development, Heliomare, Wijk aan Zee, the Netherlands;
authors: Daphne
authors: D
authors: Wezenberg
authors: Andrea G
authors: AG
authors: Cutti
authors: Antonino
authors: A
authors: Bruno
authors: Han
authors: H
authors: Houdijk
mesh_terms: D000328:Adult; D000368:Aged; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D004734:Energy Metabolism / Q000502:physiology*; D005528:Foot; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D055595:Mechanical Phenomena; D008875:Middle Aged; D011474:Prosthesis Design; D016138:Walking / Q000502:physiology*
keywords: ESAR prosthetic foot; SACH prosthetic foot; amputation; ankle power; center of mass mechanics; gait; lower-limb prosthesis; mechanical energy; roll-over shape; walking