A close relationship exists between hand skill and the excitability of motor neurons innervating the postural soleus muscle in right-handed male subjects.
The claim that there is no consistent inhibition of the H-reflex from the dominant leg was examined and rejected. Hand preference was assessed by the Edinburgh Inventory, and hand skill by the peg moving task. It was re-established that there is an inverse relationship between hand skill and the excitability of motoneurons innervating the postural soleus muscle in right-handed subjects without familial sinistrality. There was no significant difference between the recovery curves from the right and left sides in subjects with familial sinistrality. There was a positive linear correlation between the asymmetry index for hand skill greater than zero (right-hand dominance) and the asymmetry index for the H-reflex recovery curve greater than zero (left dominance in motoneuronal excitability). It was concluded that there is indeed a spinal motor asymmetry in postural leg muscles related to handedness.
Tan
U
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Atatürk University, Medical Faculty, Institute of Physiology, Erzurum, Turkey.
D000328:Adult; D007839:Functional Laterality; D006181:H-Reflex / Q000502:physiology*; D006225:Hand / Q000502:physiology*; D006801:Humans; D007866:Leg; D008297:Male; D009046:Motor Neurons / Q000502:physiology*; D009048:Motor Skills; D009132:Muscles / Q000294:innervation*; D011187:Posture / Q000502:physiology*