TY - JOUR
T1 - Architectural and functional features of human triceps surae muscles during contraction
AU - Kawakami, Yasuo
AU - Ichinose, Yoshiho
AU - Fukunaga, Tetsuo
PY - 1998/8
Y1 - 1998/8
N2 - Architectural properties of the triceps surae muscles were determined in vivo for six men. The ankle was positioned at 15°dorsiflexion (-15°) and 0, 15, and 30°plantar flexion, with the knee set at 0, 45, and 90°. At each position, longitudinal ultrasonic images of the medial (MG) and lateral (LG) gastrocnemius and soleus (Sol) muscles were obtained while the subject was relaxed (passive) and performed maximal isometric plantar flexion (active), from which fascicle lengths and angles with respect to the aponeuroses were determined. In the passive condition, fascicle lengths changed from 59, 65, and 43 mm (knee, 0°; ankle, -15°) to 32, 41, and 30 mm (knee, 90°ankle, 30°) for MG, LG, and Sol, respectively. Fascicle shortening by contraction was more pronounced at longer fascicle lengths. MG had greatest fascicle angles, ranging from 22 to 67°, and was in a very disadvantageous condition when the knee was flexed at 90°, irrespective of ankle positions. Different lengths and angles of fascicles, and their changes by contraction, might be related to differences in force-producing capabilities of the muscles and elastic characteristics of tendons and aponeuroses.
AB - Architectural properties of the triceps surae muscles were determined in vivo for six men. The ankle was positioned at 15°dorsiflexion (-15°) and 0, 15, and 30°plantar flexion, with the knee set at 0, 45, and 90°. At each position, longitudinal ultrasonic images of the medial (MG) and lateral (LG) gastrocnemius and soleus (Sol) muscles were obtained while the subject was relaxed (passive) and performed maximal isometric plantar flexion (active), from which fascicle lengths and angles with respect to the aponeuroses were determined. In the passive condition, fascicle lengths changed from 59, 65, and 43 mm (knee, 0°; ankle, -15°) to 32, 41, and 30 mm (knee, 90°ankle, 30°) for MG, LG, and Sol, respectively. Fascicle shortening by contraction was more pronounced at longer fascicle lengths. MG had greatest fascicle angles, ranging from 22 to 67°, and was in a very disadvantageous condition when the knee was flexed at 90°, irrespective of ankle positions. Different lengths and angles of fascicles, and their changes by contraction, might be related to differences in force-producing capabilities of the muscles and elastic characteristics of tendons and aponeuroses.
KW - Gastrocnemius and soleus muscles
KW - Length-force relationship
KW - Pennate muscle
KW - Ultrasonography
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U2 - 10.1152/jappl.1998.85.2.398
DO - 10.1152/jappl.1998.85.2.398
M3 - Article
C2 - 9688711
AN - SCOPUS:0031880206
VL - 85
SP - 398
EP - 404
JO - Journal of Applied Physiology Respiratory Environmental and Exercise Physiology
JF - Journal of Applied Physiology Respiratory Environmental and Exercise Physiology
SN - 8750-7587
IS - 2
ER -