TY - JOUR
T1 - Modulation of soleus H-reflex amplitude and variance during pretibial contraction - Effects of joint position and effort level
AU - Hwang, Ing Shiou
AU - Lin, Yu Chin
AU - Ho, Kai Yu
N1 - Funding Information:
Received 2 February 2002. This research was financially supported by grants from the National Science Council, R.O.C., under grant no. NSC 89-2314-B006-191. Address correspondence to Ing-Shiou Hwang, PhD, Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan. E-mail: [email protected]
PY - 2002
Y1 - 2002
N2 - To investigate the effects of joint position and effort level of antagonist contraction on reciprocal inhibition, experiments with 15 healthy volunteers were performed to compare the changes of standardized soleus H reflex during dorsiflexion contraction (0%, 25%, 50%, 75% maximal voluntary contraction [MVC] associated with different ankle positions (plantarflexion 20°, neutral, and dorsi-flexion 20°). The results indicated that a decrease of the soleus H response was dependent on the level of prefibial contraction, but a significant interaction of ankle position and pretibial contraction was noted (p ≤ .05). Post hoc analysis suggested that progressive H-amplitude decrement as the pretibial contraction increased was especially significant in the plantar-flexed position, but not in the dorsiflexed position. In contrast to H-reflex amplitude, standardized intrasubject variances of the H amplitude (Hvar/Hmean) significantly increased with pretibial dorsiflexion (p < .05), but neither with the ankle position nor interaction effect (p > .05). These findings suggest that progressive reciprocal inhibition was position relevant pertaining to joint stability as well as force variability.
AB - To investigate the effects of joint position and effort level of antagonist contraction on reciprocal inhibition, experiments with 15 healthy volunteers were performed to compare the changes of standardized soleus H reflex during dorsiflexion contraction (0%, 25%, 50%, 75% maximal voluntary contraction [MVC] associated with different ankle positions (plantarflexion 20°, neutral, and dorsi-flexion 20°). The results indicated that a decrease of the soleus H response was dependent on the level of prefibial contraction, but a significant interaction of ankle position and pretibial contraction was noted (p ≤ .05). Post hoc analysis suggested that progressive H-amplitude decrement as the pretibial contraction increased was especially significant in the plantar-flexed position, but not in the dorsiflexed position. In contrast to H-reflex amplitude, standardized intrasubject variances of the H amplitude (Hvar/Hmean) significantly increased with pretibial dorsiflexion (p < .05), but neither with the ankle position nor interaction effect (p > .05). These findings suggest that progressive reciprocal inhibition was position relevant pertaining to joint stability as well as force variability.
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U2 - 10.1080/00207450290025707
DO - 10.1080/00207450290025707
M3 - Article
C2 - 12325309
AN - SCOPUS:0036018235
SN - 0020-7454
VL - 112
SP - 623
EP - 638
JO - International Journal of Neuroscience
JF - International Journal of Neuroscience
IS - 6
ER -