TY - JOUR
T1 - Differential angle-dependent modulation of the long-latency stretch reflex responses in elbow flexion synergists
AU - Yamamoto, Shin Ichiroh
AU - Nakazawa, Kimitaka
AU - Yano, Hideo
AU - Ohtsuki, Tatsuyuki
PY - 2000/4
Y1 - 2000/4
N2 - We determined the effect of elbow joint angle on the short-(M1) and long-latency stretch reflex (M2 and M3) responses of the elbow flexion synergists, the brachioradialis (BR), and the biceps brachii (BB), during weak isometric elbow flexion tasks. The elbow joint angle was 35,75 and 115°(full-extension angle was 0°), and the muscle contraction level was 0,3 and 6% of maximum voluntary contraction (MVC) of the BR. In BR, the M1, M2 and M3 responses were significantly greater at 75 and 115°than at 35°. On the other hand, in BB, the M2 response was significantly greater at 35°than at 75 and 115°, while the M1 and M3 responses were not significantly different among the elbow joint angles. These results indicated that the stretch reflex responses of BR might be dependent on the changes of muscle length in stretch stimulus, while the M2 response of BB might not be dependent on the actual stimulus intensity. Therefore, we concluded that the M2 of BB might be modulated selectively by a higher reflex center in accordance with relationships of the mechanical advantages between synergistic muscles. Copyright (C) 2000 Elsevier Science Ltd.
AB - We determined the effect of elbow joint angle on the short-(M1) and long-latency stretch reflex (M2 and M3) responses of the elbow flexion synergists, the brachioradialis (BR), and the biceps brachii (BB), during weak isometric elbow flexion tasks. The elbow joint angle was 35,75 and 115°(full-extension angle was 0°), and the muscle contraction level was 0,3 and 6% of maximum voluntary contraction (MVC) of the BR. In BR, the M1, M2 and M3 responses were significantly greater at 75 and 115°than at 35°. On the other hand, in BB, the M2 response was significantly greater at 35°than at 75 and 115°, while the M1 and M3 responses were not significantly different among the elbow joint angles. These results indicated that the stretch reflex responses of BR might be dependent on the changes of muscle length in stretch stimulus, while the M2 response of BB might not be dependent on the actual stimulus intensity. Therefore, we concluded that the M2 of BB might be modulated selectively by a higher reflex center in accordance with relationships of the mechanical advantages between synergistic muscles. Copyright (C) 2000 Elsevier Science Ltd.
KW - Biceps brachii
KW - Brachioradialis
KW - Human
KW - Motor control
KW - Stretch reflex
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U2 - 10.1016/S1050-6411(99)00025-5
DO - 10.1016/S1050-6411(99)00025-5
M3 - Article
C2 - 10699561
AN - SCOPUS:0033967352
VL - 10
SP - 135
EP - 142
JO - Journal of Electromyography and Kinesiology
JF - Journal of Electromyography and Kinesiology
SN - 1050-6411
IS - 2
ER -