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Concentric and eccentric force–velocity relationships during electrically induced submaximal contractions
Author(s) -
Kues Janet M.,
Mayhew Thomas P.
Publication year - 1996
Publication title -
physiotherapy research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.509
H-Index - 49
eISSN - 1471-2865
pISSN - 1358-2267
DOI - 10.1002/pri.58
Subject(s) - concentric , eccentric , isometric exercise , quadriceps femoris muscle , quadriceps muscle , mathematics , physical medicine and rehabilitation , medicine , cardiology , physical therapy , physics , geometry , quantum mechanics
The purpose of this investigation was to examine the force–velocity relationship during electrically induced, submaximal concentric and eccentric contractions of the quadriceps femoris muscle. Thirty female subjects with no history of knee pathology participated in the study. Force was measured on an isokinetic dynamometer and the quadriceps femoris muscle was electrically stimulated by use of a medium frequency current generator. Subjects were stimulated at 30% of their maximum voluntary isometric force. Four velocities were tested (30°, 90°, 120° and 180°/sec) during both concentric and eccentric contractions. The relationship between force and velocity was examined with an analysis of covariance. The regression model describing the force–velocity relationship for concentric contractions was significant (p<0.0001) with an R 2 of 0.96 and a slope of ‐0.76 (p<0.0001). The regression model describing the force–velocity relationship for eccentric contractions was significant (p<0.0001) with an R 2 of 0.91 and a slope of 0.4 (p<0.0001). The relationship between force and velocity during electrically induced, sub‐maximal concentric and eccentric contractions were similar to in vitro studies that have examined this relationship during shortening and lengthening contractions. Copyright © 1996 Whurr Publishers Ltd.