Tendinous movement of a human muscle during voluntary contractions
determined by real-time ultrasonography.
Fukunaga, Tetsuo, Masamitsu Ito, Yoshiho Ichinose, Shinya Kuno, Yasuo
Kawakami, and Senshi Fukashiro.
Department of Life Science, The University of Tokyo, Komaba 3-8-1,
Meguro, Tokyo 153, Japan, Tsukuba Advanced Research Alliance (TARA),
University of Tsukuba, Tsukuba 305, Japan
APStracts 3:0229A, 1996.
The degree of shortening or lengthening of muscles during joint
actions has not been clarified in humans, although such information
is essential in understanding human muscle functions. In this study,
the tendinous movement of a muscle was determined by real-time
ultrasonography during voluntary contractions. The tibialis anterior
muscle (TA) was tested in five healthy males who performed dorsi- and
plantarflexion movements (shortening and lengthening of TA) at two
frequencies (0.1 and 1.5 Hz). The insertion point (h) of fascicles
onto the aponeurosis was clearly visualized on the ultrasonogram, and
its position relative to a fixed marker moved proximally/distally
according to dorsi-/plantarflexion of ankle joint. The movement of
the h occurred in phase with the angular change of ankle joint,
giving high correlations (r=0.93 to 0.97) between the displacement of
h (dl) and angle (q). The dl for one radian of joint angle change,
46.5 1.7 mm (mean SD), was comparable to the reported moment arm of
TA. The present method would have many applications in the field of
muscle physiology and biomechanics in humans.
Received 14 September 1995; accepted in final form 19 April 1996.
APS Manuscript Number A1005-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 8 May 96