Int J Sports Med 2017; 38(10): 741-746
DOI: 10.1055/s-0043-113043
Training & Testing
© Georg Thieme Verlag KG Stuttgart · New York

A Novel Two-Velocity Method for Elaborate Isokinetic Testing of Knee Extensors

Vladimir Grbic
1   University of Belgrade, Faculty of Sport and Physical Education, The Research Centre, Belgrade, Serbia
,
Sasa Djuric
1   University of Belgrade, Faculty of Sport and Physical Education, The Research Centre, Belgrade, Serbia
,
Olivera M. Knezevic
2   University of Belgrade, Institute for Medical Research, Department of Neurophysiology, Belgrade, Serbia
,
Dragan M. Mirkov
1   University of Belgrade, Faculty of Sport and Physical Education, The Research Centre, Belgrade, Serbia
,
Aleksandar Nedeljkovic
1   University of Belgrade, Faculty of Sport and Physical Education, The Research Centre, Belgrade, Serbia
,
Slobodan Jaric
3   Kinesiology and Applied Physiology, & Biomechanics and Movement Science, University of Delaware, Newark, United States
› Author Affiliations
Further Information

Publication History



accepted after revision 22 May 2017

Publication Date:
02 August 2017 (online)

Preview

Abstract

Single outcomes of standard isokinetic dynamometry tests do not discern between various muscle mechanical capacities. In this study, we aimed to (1) evaluate the shape and strength of the force-velocity relationship of knee extensors, as observed in isokinetic tests conducted at a wide range of angular velocities, and (2) explore the concurrent validity of a simple 2-velocity method. Thirteen physically active females were tested for both the peak and averaged knee extensor concentric force exerted at the angular velocities of 30°–240°/s recorded in the 90°–170° range of knee extension. The results revealed strong (0.960<R<0.998) linear force-velocity relationships that depict the maximum muscle force (i.e. the force-intercept), velocity (velocity-intercept), and power (their product). Moreover, the line drawn through only the 60° and 180°/s data (the ‘2-velocity method’) revealed a high level of agreement with the force-velocity relationship obtained (0.76<R<0.97; all power<0.001); while the force-intercept highly correlated (0.68<R<0.84; all power≤0.01) with the directly measured isometric force. The 2-velocity method could therefore be developed into a standard method for isokinetic testing of mechanical capacities of knee extensors and, if supported by further research, other muscles. This brief and fatigue-free testing procedure could discern between muscle force, velocity, and power-producing capacities.