Relationships between hand skill and the excitability of motoneurons innervating the postural soleus muscle in human subjects.

The relation of hand skill to the excitability of motoneurons innervating the postural soleus muscle was studied in normal human subjects. The motoneuronal excitability was tested by the recovery curve of the Hoffmann reflex. The hand skill was assessed by the peg moving test. Females have been found to be better than males in hand skill. It was established that the H response recovery curve from the right leg was significantly lower than that from the left leg in right handed subjects. The opposite was found in left handers. In ambidexters, there was no significant difference between the heights of the left and right recovery curves. The laterality quotients of the H response recovery curves were normally distributed in the total sample with a mean significantly less than zero, indicating a left shift bais in the motoneuronal excitability. The possible factors contributing to the inverse relationship between hand skill and the excitability of motoneurons innervating the postural soleus muscle were discussed in light of genetic determinants of brainedness and the corticospinal inputs to postural motoneurons.

[1]  U. Tan.  Lateral asymmetry of H-reflex recovery curves in cat: evidence for a spinal motor asymmetry. , 1984, The International journal of neuroscience.

[2]  D Kilshaw,et al.  Right- and left-hand skill II: Estimating the parameters of the distribution of L-R differences in males and females. , 1983, British journal of psychology.

[3]  D Kilshaw,et al.  Right- and left-hand skill I: Effects of age, sex and hand preference showing superior skill in left-handers. , 1983, British journal of psychology.

[4]  N. Geschwind,et al.  Left-handedness: association with immune disease, migraine, and developmental learning disorder. , 1982, Proceedings of the National Academy of Sciences of the United States of America.

[5]  E. Koff,et al.  asymmetry of Facial Expression Related to Handedness, Footedness, and Eyedness: a Quantitative Study , 1981, Cortex.

[6]  M. Annett,et al.  The right shift theory of handedness and developmental language problems , 1981 .

[7]  J. F. Middleton,et al.  Lateral asymmetry of the Hoffmann reflex: relation to cortical laterality. , 1980, Journal of neurology, neurosurgery, and psychiatry.

[8]  A. Nieoullon,et al.  Influence of pyramidotomy on limb flexion movements induced by cortical stimulation and on associated postural adjustment in the cat , 1978, Brain Research.

[9]  M Annett,et al.  A coordination of hand preference and skill replicated. , 1976, British journal of psychology.

[10]  B D Chaurasia,et al.  Functional asymmetry in the face. , 1975, Acta anatomica.

[11]  U. Tan.  Potentiation and depression of the motoneuronal activity following high frequency orthodromic tetanization. , 1974, Brain research.

[12]  R. C. Oldfield.  The assessment and analysis of handedness: the Edinburgh inventory. , 1971, Neuropsychologia.

[13]  H. Táboříková,et al.  Conditioning of H-reflexes by a preceding subthreshold H-reflex stimulus. , 1969, Brain : a journal of neurology.

[14]  G. Groden.  Lateral Preferences in Normal Children , 1969, Perceptual and motor skills.

[15]  H. Táboříková,et al.  Motoneurone pool and the H-reflex. , 1968, Journal of neurology, neurosurgery, and psychiatry.

[16]  E. Diamantopoulos,et al.  Excitability of spinal motor neurones in normal subjects and patients with spasticity, Parkinsonian rigidity, and cerebellar hypotonia. , 1967, Journal of neurology, neurosurgery, and psychiatry.

[17]  J. B. Preston,et al.  Functional coupling between the pyramidal tract and segmental motoneurons in cat and primate. , 1967, Journal of neurophysiology.

[18]  J. B. Preston,et al.  COMPARISON OF MOTOR CORTEX INFLUENCES UPON VARIOUS HIND-LIMB MOTONEURONS IN PYRAMIDAL CATS AND PRIMATES. , 1965, Journal of neurophysiology.

[19]  J. Eccles,et al.  Distribution of recurrent inhibition among motoneurones , 1961, The Journal of physiology.

[20]  Merrell Dj.  Dominance of eye and hand. , 1957 .