کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
3045327 1185019 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The effect of contraction intensity on force fluctuations and motor unit entrainment in individuals with essential tremor
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی عصب شناسی
پیش نمایش صفحه اول مقاله
The effect of contraction intensity on force fluctuations and motor unit entrainment in individuals with essential tremor
چکیده انگلیسی

ObjectivesQuantify the effect of increasing contraction intensity on the amplitude of force fluctuations and neuromuscular and force tremor spectral power.MethodsTwenty-one subjects with essential tremor (ET) and 22 healthy controls applied isometric wrist extension contractions. Various sub-maximal contraction intensities were evaluated (5%-, 10%-, 20%- and 30%-MVC). Force fluctuations and wrist extensor neuromuscular activity were recorded using a load cell and electromyography (EMG).ResultsHigher contraction intensities were associated with larger amplitude force fluctuations and greater neuromuscular activation. However, spectral power associated with tremor peaks remained relatively constant (EMG) or decreased (force) with increasing contraction intensity.ConclusionsMotor unit entrainment associated with centrally generated oscillatory inputs does not increase with greater levels of muscle activation.SignificanceRather than influencing a constant proportion of active motor units, abnormal oscillatory drive influences a relative constant number of total motor units. When combined with the findings from our previous study on postural tremor, the present results provide preliminary evidence that abnormal stretch reflex activity may contribute to this motor unit entrainment.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Clinical Neurophysiology - Volume 121, Issue 2, February 2010, Pages 233–239
نویسندگان
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