Analysis of the effects of firing rate and synchronization on spike-triggered averaging of multidirectional motor unit torque

Jason J. Kutch*, Nina L. Suresh, Anthony M. Bloch, William Z. Rymer

*Corresponding author for this work

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

Spike-triggered averaging (STA) of muscle force transients has often been used to estimate motor unit contractile properties, using the discharge of a motor unit within the muscle as the triggering events. For motor units that exert torque about multiple degrees-of-freedom, STA has also been used to estimate motor unit pulling direction. It is well known that motor unit firing rate and weak synchronization of motor unit discharges with other motor units in the muscle can distort STA estimates of contractile properties, but the distortion of STA estimates of motor unit pulling direction has not been thoroughly evaluated. Here, we derive exact equations that predict that STA decouples firing rate and synchronization distortion when used to estimate motor unit pulling direction. We derive a framework for analyzing synchronization, consider whether the distortion due to synchronization can be removed from STA estimates of pulling direction, and show that there are distributions of motor unit pulling directions for which STA is insensitive to synchronization. We conclude that STA may give insight into how motoneuronal synchronization is organized with respect to motor unit pulling direction.

Original languageEnglish (US)
Pages (from-to)347-361
Number of pages15
JournalJournal of Computational Neuroscience
Volume22
Issue number3
DOIs
StatePublished - Jun 1 2007

Keywords

  • Firing rate
  • Motorunit
  • Pulling direction
  • Spike-triggered averaging
  • Synchronization

ASJC Scopus subject areas

  • Sensory Systems
  • Cognitive Neuroscience
  • Cellular and Molecular Neuroscience

Fingerprint Dive into the research topics of 'Analysis of the effects of firing rate and synchronization on spike-triggered averaging of multidirectional motor unit torque'. Together they form a unique fingerprint.

  • Cite this