A CLOSE RELATIONSHIP BETWEEN HAND SKILL AND THE EXCITABILITY OF MOTOR NEURONS INNERVATING THE POSTURAL SOLEUS MUSCLE IN RIGHT-HANDED FEMALE SUBJECTS

The claim that there is not a 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. All the subjects were right-handed in preference and skill. 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 female subjects without familial sinstrality. There was no significant difference between the recovery curves from the right and left sides in subjects with familial sinistrality. The H reflex from right leg was different between these right-handers. There was a positive linear correlation between the asymmetry index of hand skill greater than zero (right-hand dominance) and the asymmetry index for H-reflex recovery curve greater than zero (left dominance in reflex activity). It was concluded that there is a spinal motor asymmetry in postural leg muscles to handedness. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.