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Motor cortex excitability during ballistic forearm and finger movements
Author(s) -
Mills Kerry R.,
Kimiskidis Vasilios
Publication year - 1996
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/(sici)1097-4598(199604)19:4<468::aid-mus7>3.0.co;2-a
Subject(s) - biceps , transcranial magnetic stimulation , motor cortex , forearm , neuroscience , electromyography , evoked potential , spinal cord , index finger , agonist , psychology , medicine , anatomy , physical medicine and rehabilitation , stimulation , receptor
In a ballistic forearm flexion movement, a centrally programmed triphasic pattern of electromyogram (EMG) is seen with two bursts in biceps and a single burst in triceps. Rapid abduction of the index finger, in contrast, is achieved with a single agonist burst. Transcranial magnetic and electrical stimuli, triggered at the onset of the EMG burst, have been used to probe cortical and spinal cord excitability during and after self‐paced ballistic finger and forearm movements. In both, the motor cortex has two phases of increased excitability. The first phase is coincident with the initial agonist burst. The second phase in biceps is associated with the second agonist burst, but in the finger movement, the raised motor cortical excitability is not associated with any EMG. It is argued that the motor program for the two movements may be similar, despite there being large differences in the EMG pattern generated. © 1996 John Wiley & Sons, Inc.