The Effect Of Stabilization Versus Nonstabilization Of The Nontested Lower Extremity On Quadriceps Torque Production During An Isokinetic Test

Author : Daniel Gary Syrotuik
Publisher : National Library of Canada
ISBN 13 : 9780315194090
Total Pages : 0 pages
Book Rating : 4.1/5 (94 download)

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Download or read book Resistive Torque Analysis of the Nautilus Leg Extension Machine [microform] written by Daniel Gary Syrotuik and published by National Library of Canada. This book was released on 1984 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was the purpose of this study to determine to what extent the ability of a Nautilus leg extension machine (NLEM) provided resistance that varied in proportion to the biomechanical capability of the quadri ceps muscle group. Specifically, this study examined isokinetic human torque curves (HTC) indicative of the variable strength pattern of the quadriceps muscle group of a selected sample of 75 physically active male and female subjects over a 90° range of motion at three pre-determined rates of angular velocity. These curves were compared with machine resistive torque (MRT) curves generated on the NLEM at two pre-determined rates of angular velocity. Measurements of the HTC were made with a two channel Cybex I I isokinetic device at 0.524, 1.048 and 1.572 r/s. Peak torque and torque at 90 (vertical), 105, 120, 135, 150, 165 and 180° (horizontal) were measured from maximal recorded torque achieved during three voluntary leg extensions. These values were transformed to percent of maximum value and plotted to illustrate the human quadriceps torque capability throughout knee extension. The testing of the NLEM resistive torque utilized a specially constructed leg extension dynamometer which was capable of measuring changes in torque and the angle at which it occurred (33). Angular velocities of 0.263 and 0.524 r/s were selected to approximate the manufacturer's recommended speed for optimal strength benefits. Peak torque and the torque at the same angles as for the HTC were measured and normalized to plot the MRT curves. Test results demonstrated three distinctive human torque capability curves, represen tative of the muscle's angle of pull, Iengfh/tension and angular velocity interaction. The mean shape and form of the NLEM's MRT curves were identical in pattern and peak torque, regardless of plate load or level arm angular velocity, and were not similar to the HTCs. The present study observed that the regulated resistance of the NLEM, via the cam device, did not match the changing biomechanical capability of the quadriceps, at any of the tested angular velocities, regardless of the plate load.