|
|
||||||||
Department of Life Sciences, University of Tokyo, Komaba, 3-7-1, Meguro, Tokyo, Japan
To determine the shortening velocities of fascicles of the vastus lateralis muscle (VL) during isokinetic knee extension, six male subjects were requested to extend the knee with maximal effort at angular velocities of 30 and 150°/s. By using an ultrasonic apparatus, longitudinal images of the VL were produced every 30 ms during knee extension, and the fascicle length and angle of pennation were obtained from these images. The shortening fascicle length with extension of the knee (from 98 to 13° of knee angle; full extension = 0°) was greater (43 mm) at 30°/s than at 150°/s (35 mm). Even when the angular velocity remained constant during the isokinetic range of motion, the fascicle velocity was found to change from 39 to 77 mm/s at 150°/s and from 6 to 19 mm/s at 30°/s. The force exerted by a fascicle changed with the length of the fascicle at changing angular velocities. The peak values of fascicle force and velocity were observed at ~90 mm of fascicle length. In conclusion, even if the angular velocity of knee extension is kept constant, the shortening velocity of a fascicle is dependent on the force applied to the muscle-tendon complex, and the phenomenon is considered to be caused mainly by the elongation of the elastic element (tendinous tissue).
isokinetic knee extension; fascicle shortening velocity; force-velocity relationship
This article has been cited by other articles:
![]() |
N. D. Reeves, C. N. Maganaris, S. Longo, and M. V. Narici Differential adaptations to eccentric versus conventional resistance training in older humans Exp Physiol, July 1, 2009; 94(7): 825 - 833. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. D. R. Harridge Plasticity of human skeletal muscle: gene expression to in vivo function Exp Physiol, September 1, 2007; 92(5): 783 - 797. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. F. Hoyt, S. J. Wickler, A. A. Biewener, E. A. Cogger, and K. L. De La Paz In vivo muscle function vs speed I. Muscle strain in relation to length change of the muscle-tendon unit J. Exp. Biol., March 15, 2005; 208(6): 1175 - 1190. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. D. Reeves and M. V. Narici Behavior of human muscle fascicles during shortening and lengthening contractions in vivo J Appl Physiol, September 1, 2003; 95(3): 1090 - 1096. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Muraoka, Y. Kawakami, M. Tachi, and T. Fukunaga Muscle fiber and tendon length changes in the human vastus lateralis during slow pedaling J Appl Physiol, November 1, 2001; 91(5): 2035 - 2040. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Kurokawa, T. Fukunaga, and S. Fukashiro Behavior of fascicles and tendinous structures of human gastrocnemius during vertical jumping J Appl Physiol, April 1, 2001; 90(4): 1349 - 1358. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |