Evaluation of force-velocity characteristics of quadriceps muscles by means of peak torque-angular velocity relationship during knee extension and flexion

Abstract

In this thesis, an experiment, which shows that there is a relationship between theoretical force-velocity characteristics of a muscle fiber and experimental peak torqueangular velocity characteristics of quadriceps muscle contraction using CYBEX NORM isokinetic dynamometer, is presented. First, the equations of force-velocity relationship for muscle fiber contraction were derived using a special cross-bridge theory. Then, during the experiments, the subject performed knee extension and flexion movements with different angular velocities. In this way, peak torque values at different angular velocities were obtained during eccentric, isometric and concentric contraction of quadriceps muscles. Finally, it was observed that the theoretical curve of force-velocity for muscle fiber contraction could fit the experimental data showing the relationship of peak torque-angular velocity for quadriceps muscles quite well. As a result, although many parameters were not controlled during the experiments, force-velocity curve of the muscles was applicable for different conditions.|Keywords: peak torque, angular velocity, force, isometric contraction, concentric contraction, eccentric contraction, isokinetic dynamometer.