Physiologic Tremor

Part of the Contemporary Clinical Neuroscience book series (CCNE)


Physiologic tremor is barely visible to the unaided eye unless it is enhanced by fatigue, anxiety, or a medication (e.g., thyroxin and beta-adrenergic drugs). Consequently, the study of physiologic tremor requires the use of sensitive motion transducers such as miniature accelerometers, gyroscopic angular velocity transducers, or force transducers. Muscle activity is recorded electromyographically, using skin electrodes for gross motor activity and needle electrodes for single motor unit activity (Elble and Deuschl 2002). Motion transducer and electromyographic (EMG) signals are usually recorded digitally with a computer and analyzed using spectral (Fourier) techniques to determine the amplitude and frequency of tremor and the coherence (linear correlation squared) between tremor and EMG activity. These electrophysiologic methods are also used to quantify the effect of mass (inertial) and spring (elastic) loading on tremor frequency. Using these methods, investigators have demonstrated mechanical-reflex and central-neurogenic mechanisms of physiologic tremor.


Physiologic tremor Accelerometry Electromyography Oscillation Stretch reflex Biomechanics 


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© Springer Science+Business Media New York 2013

Authors and Affiliations

  1. 1.Department of NeurologySouthern Illinois University School of MedicineSpringfieldUSA

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