Mechanical analysis and hierarchies of multidigit synergies during accurate object rotation

Wei Zhang, Halla B. Olafsdottir, Vladimir M. Zatsiorsky, Mark L. Latash

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

We studied the mechanical variables (the grip force and the total moment of force) and multidigit synergies at two levels (the virtual finger-thumb level, VF-TH, and the individual finger level, IMRL) of a hypothetical control hierarchy during accurate rotation of a hand-held instrumented handle. Synergies were defined as covaried changes in elemental variables (forces and moments of force) that stabilize the output at a particular level. Indices of multidigit synergies showed higher values at the hierarchically higher level (VF-TH) for both normal and tangential forces. The moment of force was stabilized at both hierarchical levels during the steady-state phases but not during the movement. The results support the principles of superposition and of mechanical advantage. They also support an earlier hypothesis on an inherent trade-off between synergies at the two hierarchical levels, although the controller showed more subtle and versatile synergic control than the one hypothesized earlier.

Original languageEnglish (US)
Pages (from-to)251-279
Number of pages29
JournalMotor control
Volume13
Issue number3
DOIs
StatePublished - Jul 2009

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Fingers
Thumb
Hand Strength
Hand

All Science Journal Classification (ASJC) codes

  • Physical Therapy, Sports Therapy and Rehabilitation
  • Clinical Neurology
  • Physiology (medical)

Cite this

Zhang, Wei ; Olafsdottir, Halla B. ; Zatsiorsky, Vladimir M. ; Latash, Mark L. / Mechanical analysis and hierarchies of multidigit synergies during accurate object rotation. In: Motor control. 2009 ; Vol. 13, No. 3. pp. 251-279.
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Mechanical analysis and hierarchies of multidigit synergies during accurate object rotation. / Zhang, Wei; Olafsdottir, Halla B.; Zatsiorsky, Vladimir M.; Latash, Mark L.

In: Motor control, Vol. 13, No. 3, 07.2009, p. 251-279.

Research output: Contribution to journalArticle

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