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Cutaneous withdrawal reflexes of the upper extremity
Author(s) -
Floeter Mary Kay,
Gerloff Christian,
Kouri Joshua,
Hallett Mark
Publication year - 1998
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(199805)21:5<591::aid-mus5>3.0.co;2-3
Subject(s) - forearm , reflex , electromyography , habituation , stimulus (psychology) , stimulation , upper limb , medicine , physical medicine and rehabilitation , anatomy , flexor muscles , silent period , psychology , neuroscience , anesthesia , transcranial magnetic stimulation , psychotherapist
We characterized reflexes of the upper limb elicited by electrical stimulation of the fingers. Surface electromyogram (EMG) was recorded from several upper extremity muscles, and a finger was stimulated through paired ring electrodes. A train of 4–10 shocks at a frequency of 300 Hz and an intensity 4–6 times the perceptual threshold was the most effective stimulus for evoking EMG activity in relaxed arm muscles. Habituation was prominent. Latencies of EMG activity were <100 ms for most proximal and forearm muscles, and at least 40 ms prior to voluntary withdrawal movements. The timing of EMG activity in arm muscles was similar to that of the E2 component of the cutaneomuscular reflex evoked in these same muscles during contraction, and coincided with a silent period in active hand muscles. We conclude that cutaneous stimuli to the fingers activate a complex motor pattern that tends to withdraw the hand at the same time the grasp is released. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:591–598, 1998.