Premium
THE SILENT PERIOD IN SPASTIC, RIGID, AND NORMAL SUBJECTS DURING ISOTONIC AND ISOMETRIC MUSCLE CONTRACTIONS
Author(s) -
Dietrichson Per
Publication year - 1971
Publication title -
acta neurologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.967
H-Index - 95
eISSN - 1600-0404
pISSN - 0001-6314
DOI - 10.1111/j.1600-0404.1971.tb07475.x
Subject(s) - silent period , isometric exercise , isotonic , spasticity , spastic , triceps surae muscle , medicine , electromyography , period (music) , tendon , anatomy , physical medicine and rehabilitation , cerebral palsy , physics , stimulation , transcranial magnetic stimulation , acoustics
ABSTRACT The silent period in the triceps surae muscle has been studied in seven normal subjects, six spastic, and eight Parkinsonian rigid patients by averaging 50 EMG traces from each test. In spastics the mean duration of the silent period was longer than in normals, whereas in Parkinsonian patients it did not differ significantly from normals. The duration of the silent period was independent of large variations in the twitch tension obtained by isometric and isotonic recording of the twitch, suggesting that the active inhibition from the tensionsensitive tendon organs is not the main mechanism behind the prolonged silent period in spastics. This appears primarily to be due to an increased pause in the muscle spindle afferent firing during the twitch. The increased duration of the silent period in spastics is compatible with an increased dynamic fusimotor innervation in spasticity.