Measurement of muscle fibre displacement during contraction by real-time ultrasonography in humans.
The contact point (P) made by both the echoes of the aponeurosis and from interspaces among fascicles of the tibialis anterior muscle was detected by real-time ultrasound scanning in 12 adults. Movement in the location of P was observed during muscle contraction and its displacement was related to changes in ankle joint angles (r = 0.81, P < 0.01), i.e., P shifted proximally when the ankle joint was dorsiflexed. There was also a significant positive correlation between the degree of dorsiflexion and the velocity related to the change in location of P (r = 0.84, P < 0.01). Ultrasound measurements of the displacement and the velocity of P were reproducible as there was no variation noticed among measurements on different days. It is suggested from these results that the displacement of P reflected changes in muscle length during contraction and that this amount of change corresponded to changes in joint angles.
Kuno
S
S
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Japan.
Fukunaga
T
T
D000328:Adult; D000843:Ankle Joint / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000000981:diagnostic imaging / Q000502:physiology*; D018482:Muscle, Skeletal / Q000166:cytology / Q000000981:diagnostic imaging / Q000502:physiology*; D014463:Ultrasonography