The effect of immobilization of the head and trunk on arm-cycling-induced depression of soleus motoneuron pool excitability.
The purpose of this study was to investigate the effects of immobilization of the head and trunk on arm-cycling-induced depression of leg motoneuron pool excitability. Seven healthy humans participated in this study. The subjects sat on a chair with or without immobilization of the head and trunk. The subjects rhythmically cycled a crank of the ergometer with their hands at a frequency of 1 Hz. Soleus H-reflexes were evoked during arm cycling and during stational arm position. The H-reflexes were not significantly depressed during arm cycling when the head and trunk were immobilized, but were significantly depressed during arm cycling when the head and trunk were not immobilized. The H-reflex depression during arm cycling in the non-immobilized condition was significantly larger than that in the immobilized condition. These findings support our hypothesis that the depression of leg motoneuron pool excitability induced by arm cycling is partially related to postural activity in the head and trunk.
School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino City, Osaka, Japan. hiraoka@rehab.osakafu-u.ac.jp
Koichi
K
Hiraoka
Yoichi
Y
Taniguchi
D000704:Analysis of Variance; D001132:Arm / Q000502:physiology*; D001696:Biomechanical Phenomena; D004576:Electromyography / Q000379:methods; D007839:Functional Laterality / Q000502:physiology; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D007103:Immobilization / Q000379:methods / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D018482:Muscle, Skeletal / Q000166:cytology / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology*; D055815:Young Adult