Effect of voluntary contraction with electrical stimulation to antagonist muscle on agonist H-reflex.
OBJECTIVE
Hybrid exercise (HE) was designed to use the force generated by an electrically stimulated antagonist to provide resistance to a volitionally contracting agonist. The purpose of this study was to measure and compare the soleus H-reflex before and after HE or conventional resistance exercise (CRE).


METHODS
The experiments were carried out in 18 healthy subjects (5 men and 13 women; 19-30 yr), who were divided into 2 groups of 9 for each protocol (HE or CRE). The exercise sessions lasted for 15 consecutive minutes. The soleus Hmax/Mmax was measured before and after the HE or the CRE.


RESULTS
In the HE group, although there was no significant difference, the soleus Hmax/Mmax after the exercise increased compared with before the exercise (54.7 +/- 10.2% to 59.0 +/- 14.5%). On the other hand, the soleus Hmax/Mmax decreased in the CRE group (61.8 +/- 14.9% to 55.7 +/- 16.1%). In the rate of change of the soleus Hmax/Mmax, the result for the HE group was significantly higher than in the CRE group (108.0 +/- 11.7% and 89.1 +/- 8.0%, respectively) (p < 0.001).


CONCLUSIONS
Our results show a clear difference of the neurophysiological mechanism between HE and CRE. Thus, HE might not be an alternative method for CRE.
Yamaguchi
T
T
Keio University Tsukigase Rehabilitation Center, Izu-Shi, Shizuoka-Ken, Japan. yamaguchi@ktrc.med.keio.ac.jp
Tanabe
S
S
Watanabe
T
T
Muraoka
Y
Y
D000328:Adult; D000843:Ankle Joint / Q000502:physiology; D004576:Electromyography; D005260:Female; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013979:Tibial Nerve / Q000502:physiology; D004561:Transcutaneous Electric Nerve Stimulation