01 April 2005 : Original article
Neuromuscular control of physiological tremor during elastic load
Masato Takanokura, Kazuyoshi SakamotoMed Sci Monit 2005; 11(4): CR143-152 :: ID: 15874
Abstract
Background:Physiological tremor is an involuntary and continuous oscillation in every limb segment of a healthy human. This study investigates the neuromuscular control of physiological tremor by an elastic load applied to the middle finger.Material/Methods:The subject maintained a stretching position of the middle finger against various tension springs. Physiological tremor was detected by an acceleration sensor attached to the middle finger. The motor-unit activity was estimated by surface electromyogram (EMG) measured from the extensor digitorum communis muscle with physiological tremor. The tremor and the EMG signals were analyzed by power and coherence spectra.Results:Three frequency components appeared in physiological tremor while the subject extended the middle finger against the tension spring. They were classified as two load-independent components and a load-dependent component. Although the motor-unit activity was enhanced by the extension of the middle finger against a stiffer spring, the tremor amplitude did not significantly change. The extensor digitorum communis muscle produced a larger contraction force to maintain the finger posture against a stiffer spring, while the stiffness of the tension spring restrained the finger movement. The three frequency components of physiological tremor correlated with the motor-unit activity. These results supported the hypothesis of the origin of physiological tremor. The stretch-reflex system caused the load-dependent component, and the mechanical property of the elastic load determined its frequency. The supraspinal system produced the two load-independent components.Conclusions:The neuromuscular control to maintain the stretching of the middle finger against the elastic load gave rise to the three frequency components in physiological tremor.
Keywords: Alcoholism - physiopathology, Alcoholism - urine, Elasticity, Hand - innervation, Motor Activity, Muscle, Skeletal - innervation, Neuromuscular Junction - physiology, Posture, Tremor - physiopathology, Weight-Bearing, Alcoholism - urine, Elasticity, Hand - innervation, Motor Activity, Muscle, Skeletal - innervation, Neuromuscular Junction - physiology, Posture, Tremor - physiopathology, Weight-Bearing
Editorial
01 May 2024 : Editorial
Editorial: First Regulatory Approval for Adoptive Cell Therapy with Autologous Tumor-Infiltrating Lymphocytes (TILs) – Lifileucel (Amtagvi)DOI: 10.12659/MSM.944927
Med Sci Monit 2024; 30:e944927
In Press
09 May 2024 : Review article
A Review of the Current Status of Disease-Modifying Therapies and Prevention of Alzheimer’s DiseaseMed Sci Monit In Press; DOI: 10.12659/MSM.945091
09 Apr 2024 : Clinical Research
Correlation between Thalamocortical Tract and Default Mode Network with Consciousness Levels in Hypoxic-Isc...Med Sci Monit In Press; DOI: 10.12659/MSM.943802
19 Apr 2024 : Clinical Research
Comparative Analysis of Postoperative Sagittal Balance in Expansive Open-Door Laminoplasty versus Laminecto...Med Sci Monit In Press; DOI: 10.12659/MSM.943057
20 Mar 2024 : Clinical Research
Prevalence and Management of Chronic Pain, Including Neuropathic Pain, in Dialysis Patients with End-Stage ...Med Sci Monit In Press; DOI: 10.12659/MSM.943808
Most Viewed Current Articles
17 Jan 2024 : Review article
Vaccination Guidelines for Pregnant Women: Addressing COVID-19 and the Omicron VariantDOI :10.12659/MSM.942799
Med Sci Monit 2024; 30:e942799
14 Dec 2022 : Clinical Research
Prevalence and Variability of Allergen-Specific Immunoglobulin E in Patients with Elevated Tryptase LevelsDOI :10.12659/MSM.937990
Med Sci Monit 2022; 28:e937990
16 May 2023 : Clinical Research
Electrophysiological Testing for an Auditory Processing Disorder and Reading Performance in 54 School Stude...DOI :10.12659/MSM.940387
Med Sci Monit 2023; 29:e940387
01 Jan 2022 : Editorial
Editorial: Current Status of Oral Antiviral Drug Treatments for SARS-CoV-2 Infection in Non-Hospitalized Pa...DOI :10.12659/MSM.935952
Med Sci Monit 2022; 28:e935952