Article

The purpose of the current study was to examine the reproducibility of fascicle
length and pennation angle of gastrocnemius medialis while human walking. To the
best of our knowledge, this is the first study of the reproducibility of fascicle
length and pennation angle of gastrocnemius medialis in vivo during human gait.
Twelve males performed 10 gait trials on a treadmill, in 2 separate days. B-mode
ultrasonography, with the ultrasound probe firmly adjusted in the transverse and
frontal planes using a special cast, was used to measure the fascicle length and
the pennation angle of the gastrocnemius medialis (GM). A Vicon 624 system with
three cameras operating at 120 Hz was also used to record the ankle and knee
joint angles. The results showed that measurements of fascicle length and
pennation angle showed high reproducibility during the gait cycle, both within
the same day and between different days. Moreover, the root mean square
differences between the repeated waveforms of both variables were very small,
compared with their ranges (fascicle length: RMS= approximately 3mm, range: 38-63
mm; pennation angle: RMS= approximately 1.5 degrees, range: 22-32 degrees).
However, their reproducibility was lower compared to the joint angles. It was
found that representative data have to be derived by a wide number of gait trials
(fascicle length approximately six trials, pennation angle more than 10 trials),
to assure the reliability of the fascicle length and pennation angle in human
gait.

Langue : ANGLAIS