Method to measure tone of axial and proximal muscle

Victor S. Gurfinkel, Timothy W. Cacciatore, Paul J. Cordo, Fay B. Horak

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the vertical axis during stance, so as to twist the neck, trunk or hip regions. This twisting imposes length changes on axial muscles without changing the body's relationship to gravity. Because Twister does not provide postural support, tone must be regulated to counteract gravitational torques. We quantify this tonic regulation by the restive torque to twisting, which reflects the state of all muscles undergoing length changes, as well as by electromyography of relevant muscles. Because tone is characterized by long-lasting low-level muscle activity, tonic control is studied with slow movements that produce "tonic" changes in muscle length, without evoking fast "phasic" responses. Twister can be reconfigured to study various aspects of muscle tone, such as co-contraction, tonic modulation to postural changes, tonic interactions across body segments, as well as perceptual thresholds to slow axial rotation. Twister can also be used to provide a quantitative measurement of the effects of disease on axial and proximal postural tone and assess the efficacy of intervention.

Original languageEnglish (US)
Article numbere3677
JournalJournal of Visualized Experiments
Issue number58
DOIs
StatePublished - 2011

Fingerprint

Muscle
Muscles
Torque
Electromyography
Body Regions
Gravitation
Hip
Neck
Extremities
Maintenance
Modulation
Equipment and Supplies

Keywords

  • Issue 58
  • Medicine
  • Motor control
  • Muscle tone
  • Posture
  • Stiffness

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Chemical Engineering(all)
  • Immunology and Microbiology(all)
  • Neuroscience(all)

Cite this

Method to measure tone of axial and proximal muscle. / Gurfinkel, Victor S.; Cacciatore, Timothy W.; Cordo, Paul J.; Horak, Fay B.

In: Journal of Visualized Experiments, No. 58, e3677, 2011.

Research output: Contribution to journalArticle

Gurfinkel, Victor S. ; Cacciatore, Timothy W. ; Cordo, Paul J. ; Horak, Fay B. / Method to measure tone of axial and proximal muscle. In: Journal of Visualized Experiments. 2011 ; No. 58.
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