Abstract
The objective of this study was to examine the changes in H reflex sensitivity after neuromuscular fatigue associated with fluctuations of the M wave. In the maximal and submaximal voluntary contraction (MVC and SMVC) paradigms, subjects performed voluntary plantarflexion at 100% MVC and 40% MVC respectively until the limit of torque maintenance was reached. In the submaximal electrical stimulation (SMES) paradigm, the tricep surae was exhausted with sustained electrical stimulation of 40% of the maximal tolerable intensity at a 40-Hz stimulus rate. The H reflexes and maximal M waves (Mmax) of the soleus were recorded before and after the three fatigue paradigms, and the H reflex was standardized with Mmax to minimize possible bias due to fatigue-induced M wave fluctuation. The results showed a significant increase in the standardized H reflex due to the SMES paradigm in spite of Mmax potentiation. The SMVC paradigm led to a reduction in size of the standardized H reflex without modification of Mmax, whereas the standardized H reflex was not mediated by the MVC paradigm, which contributed to a noticeable Mmax potentiation. The present study underscored the fact that the H reflex sensitivity and M wave amplitude were not necessarily suppressed consequent to neuromuscular fatigue, but varied with the activation history of a muscle for size-dependent efficacy of the Ia transmission pathways and postactivation potentiation.
| Original language | English |
|---|---|
| Pages (from-to) | 1317-1330 |
| Number of pages | 14 |
| Journal | International Journal of Neuroscience |
| Volume | 118 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 2008 Sep 1 |
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All Science Journal Classification (ASJC) codes
- Neuroscience(all)
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Assessment of H reflex sensitivity with M wave alternation consequent to fatiguing contractions. / Hwang, Ing-Shiou; Huang, Cheng Ya; Wu, Pei Shan; Chen, Yi Ching; Wang, Chun Hou.
In: International Journal of Neuroscience, Vol. 118, No. 9, 01.09.2008, p. 1317-1330.Research output: Contribution to journal › Article
TY - JOUR
T1 - Assessment of H reflex sensitivity with M wave alternation consequent to fatiguing contractions
AU - Hwang, Ing-Shiou
AU - Huang, Cheng Ya
AU - Wu, Pei Shan
AU - Chen, Yi Ching
AU - Wang, Chun Hou
PY - 2008/9/1
Y1 - 2008/9/1
N2 - The objective of this study was to examine the changes in H reflex sensitivity after neuromuscular fatigue associated with fluctuations of the M wave. In the maximal and submaximal voluntary contraction (MVC and SMVC) paradigms, subjects performed voluntary plantarflexion at 100% MVC and 40% MVC respectively until the limit of torque maintenance was reached. In the submaximal electrical stimulation (SMES) paradigm, the tricep surae was exhausted with sustained electrical stimulation of 40% of the maximal tolerable intensity at a 40-Hz stimulus rate. The H reflexes and maximal M waves (Mmax) of the soleus were recorded before and after the three fatigue paradigms, and the H reflex was standardized with Mmax to minimize possible bias due to fatigue-induced M wave fluctuation. The results showed a significant increase in the standardized H reflex due to the SMES paradigm in spite of Mmax potentiation. The SMVC paradigm led to a reduction in size of the standardized H reflex without modification of Mmax, whereas the standardized H reflex was not mediated by the MVC paradigm, which contributed to a noticeable Mmax potentiation. The present study underscored the fact that the H reflex sensitivity and M wave amplitude were not necessarily suppressed consequent to neuromuscular fatigue, but varied with the activation history of a muscle for size-dependent efficacy of the Ia transmission pathways and postactivation potentiation.
AB - The objective of this study was to examine the changes in H reflex sensitivity after neuromuscular fatigue associated with fluctuations of the M wave. In the maximal and submaximal voluntary contraction (MVC and SMVC) paradigms, subjects performed voluntary plantarflexion at 100% MVC and 40% MVC respectively until the limit of torque maintenance was reached. In the submaximal electrical stimulation (SMES) paradigm, the tricep surae was exhausted with sustained electrical stimulation of 40% of the maximal tolerable intensity at a 40-Hz stimulus rate. The H reflexes and maximal M waves (Mmax) of the soleus were recorded before and after the three fatigue paradigms, and the H reflex was standardized with Mmax to minimize possible bias due to fatigue-induced M wave fluctuation. The results showed a significant increase in the standardized H reflex due to the SMES paradigm in spite of Mmax potentiation. The SMVC paradigm led to a reduction in size of the standardized H reflex without modification of Mmax, whereas the standardized H reflex was not mediated by the MVC paradigm, which contributed to a noticeable Mmax potentiation. The present study underscored the fact that the H reflex sensitivity and M wave amplitude were not necessarily suppressed consequent to neuromuscular fatigue, but varied with the activation history of a muscle for size-dependent efficacy of the Ia transmission pathways and postactivation potentiation.
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U2 - 10.1080/00207450802055606
DO - 10.1080/00207450802055606
M3 - Article
VL - 118
SP - 1317
EP - 1330
JO - International Journal of Neuroscience
JF - International Journal of Neuroscience
SN - 0020-7454
IS - 9
ER -