Variable-cam resistance training machines: Do they match the angle-torque relationship in humans?
Deutscher übersetzter Titel: | Widerstandstrainingsgeräte mit variablem Hub: Erreichen sie das Winkel-Drehmoment-Verhältnis des Menschen? |
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Autor: | Folland, Jonathan; Morris, Beth |
Erschienen in: | Journal of sports sciences |
Veröffentlicht: | 26 (2008), 2, S. 163-169, Lit. |
Format: | Literatur (SPOLIT) |
Publikationstyp: | Zeitschriftenartikel |
Medienart: | Gedruckte Ressource |
Sprache: | Englisch |
ISSN: | 0264-0414, 1466-447X |
DOI: | 10.1080/02640410701370663 |
Schlagworte: | |
Online Zugang: | |
Erfassungsnummer: | PU201407006812 |
Quelle: | BISp |
Abstract
The aim of this study was to determine the extent to which the resistance provided by variable-cam resistance training machines match joint torque capability. Eight variable-cam knee extension machines from six different manufacturers were assessed. Resistive torque for a constant weight/load was measured at five knee joint angles. Knee extensor muscle torque capability – the angle – torque relationship – of 10 healthy young men was determined isometrically and dynamically at the same five angles. After normalization, the two relationships were compared. The angle – torque relationship of the knee extensors displayed an inverted “U” shape as expected, with dynamic torque changing by +40% on the ascending limb (1.75 – 1.40 rad) and −60% on the descending limb (1.05 – 0.35 rad) of the angle – torque relationship. The angle – torque relationship of the different training machines was highly variable, but consistently less curvilinear and significantly different from knee extensor capabilities, with changes in torque of +2.5 to +22.2% (ascending limb) and +37.6 to −20.5% (descending limb). It is recommended that variable-cam resistance training machines be designed with the angle – torque relationship of the relevant joint and the inertial profile of the lifting exercise in mind. Verf.-Referat