Manipulation of a fragile object by elderly individuals

Stacey L. Gorniak, Vladimir M. Zatsiorsky, Mark Latash

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

We investigated strategies of healthy elderly participants (74-84 years old) during prehension and transport of an object with varying degrees of fragility. Fragility was specified as the maximal normal force that the object could withstand without collapsing. Specifically, kinetic and kinematic variables as well as and force covariation indices were quantified and compared to those shown by young healthy persons (19-28 years old). We tested three hypotheses related to age-related changes in two safety margins (slip safety margin and crush safety margin) and indices of force covariation. Compared to young controls, elderly individuals exhibited a decrease in object acceleration and an increase in movement time, an increase in grip force production, a decrease in the correlation between grip and load forces, an overall decrease in indices of multi-digit synergies, and lower safety margin indices computed with respect to both dropping and crushing the object. Elderly participants preferred to be at a relatively lower risk of crushing the object even if this led to a higher risk of dropping it. Both groups showed an increase in the index of synergy stabilizing total normal force produced by the four fingers with increased fragility of the object. Age-related changes are viewed as a direct result of physiological changes due to aging, not adaptation to object fragility. Such changes in overall characteristics of prehension likely reflect diminished synergic control by the central nervous system of finger forces with aging. The findings corroborate an earlier hypothesis on an age-related shift from synergic to element-based control.

Original languageEnglish (US)
Pages (from-to)505-516
Number of pages12
JournalExperimental Brain Research
Volume212
Issue number4
DOIs
StatePublished - Aug 1 2011

Fingerprint

Safety
Hand Strength
Fingers
Biomechanical Phenomena
Healthy Volunteers
Central Nervous System

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)

Cite this

Gorniak, Stacey L. ; Zatsiorsky, Vladimir M. ; Latash, Mark. / Manipulation of a fragile object by elderly individuals. In: Experimental Brain Research. 2011 ; Vol. 212, No. 4. pp. 505-516.
@article{a501eabd2ffd4f689ea1ea390f70b50e,
title = "Manipulation of a fragile object by elderly individuals",
abstract = "We investigated strategies of healthy elderly participants (74-84 years old) during prehension and transport of an object with varying degrees of fragility. Fragility was specified as the maximal normal force that the object could withstand without collapsing. Specifically, kinetic and kinematic variables as well as and force covariation indices were quantified and compared to those shown by young healthy persons (19-28 years old). We tested three hypotheses related to age-related changes in two safety margins (slip safety margin and crush safety margin) and indices of force covariation. Compared to young controls, elderly individuals exhibited a decrease in object acceleration and an increase in movement time, an increase in grip force production, a decrease in the correlation between grip and load forces, an overall decrease in indices of multi-digit synergies, and lower safety margin indices computed with respect to both dropping and crushing the object. Elderly participants preferred to be at a relatively lower risk of crushing the object even if this led to a higher risk of dropping it. Both groups showed an increase in the index of synergy stabilizing total normal force produced by the four fingers with increased fragility of the object. Age-related changes are viewed as a direct result of physiological changes due to aging, not adaptation to object fragility. Such changes in overall characteristics of prehension likely reflect diminished synergic control by the central nervous system of finger forces with aging. The findings corroborate an earlier hypothesis on an age-related shift from synergic to element-based control.",
author = "Gorniak, {Stacey L.} and Zatsiorsky, {Vladimir M.} and Mark Latash",
year = "2011",
month = "8",
day = "1",
doi = "10.1007/s00221-011-2755-3",
language = "English (US)",
volume = "212",
pages = "505--516",
journal = "Experimental Brain Research",
issn = "0014-4819",
publisher = "Springer Verlag",
number = "4",

}

Manipulation of a fragile object by elderly individuals. / Gorniak, Stacey L.; Zatsiorsky, Vladimir M.; Latash, Mark.

In: Experimental Brain Research, Vol. 212, No. 4, 01.08.2011, p. 505-516.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Manipulation of a fragile object by elderly individuals

AU - Gorniak, Stacey L.

AU - Zatsiorsky, Vladimir M.

AU - Latash, Mark

PY - 2011/8/1

Y1 - 2011/8/1

N2 - We investigated strategies of healthy elderly participants (74-84 years old) during prehension and transport of an object with varying degrees of fragility. Fragility was specified as the maximal normal force that the object could withstand without collapsing. Specifically, kinetic and kinematic variables as well as and force covariation indices were quantified and compared to those shown by young healthy persons (19-28 years old). We tested three hypotheses related to age-related changes in two safety margins (slip safety margin and crush safety margin) and indices of force covariation. Compared to young controls, elderly individuals exhibited a decrease in object acceleration and an increase in movement time, an increase in grip force production, a decrease in the correlation between grip and load forces, an overall decrease in indices of multi-digit synergies, and lower safety margin indices computed with respect to both dropping and crushing the object. Elderly participants preferred to be at a relatively lower risk of crushing the object even if this led to a higher risk of dropping it. Both groups showed an increase in the index of synergy stabilizing total normal force produced by the four fingers with increased fragility of the object. Age-related changes are viewed as a direct result of physiological changes due to aging, not adaptation to object fragility. Such changes in overall characteristics of prehension likely reflect diminished synergic control by the central nervous system of finger forces with aging. The findings corroborate an earlier hypothesis on an age-related shift from synergic to element-based control.

AB - We investigated strategies of healthy elderly participants (74-84 years old) during prehension and transport of an object with varying degrees of fragility. Fragility was specified as the maximal normal force that the object could withstand without collapsing. Specifically, kinetic and kinematic variables as well as and force covariation indices were quantified and compared to those shown by young healthy persons (19-28 years old). We tested three hypotheses related to age-related changes in two safety margins (slip safety margin and crush safety margin) and indices of force covariation. Compared to young controls, elderly individuals exhibited a decrease in object acceleration and an increase in movement time, an increase in grip force production, a decrease in the correlation between grip and load forces, an overall decrease in indices of multi-digit synergies, and lower safety margin indices computed with respect to both dropping and crushing the object. Elderly participants preferred to be at a relatively lower risk of crushing the object even if this led to a higher risk of dropping it. Both groups showed an increase in the index of synergy stabilizing total normal force produced by the four fingers with increased fragility of the object. Age-related changes are viewed as a direct result of physiological changes due to aging, not adaptation to object fragility. Such changes in overall characteristics of prehension likely reflect diminished synergic control by the central nervous system of finger forces with aging. The findings corroborate an earlier hypothesis on an age-related shift from synergic to element-based control.

UR - http://www.scopus.com/inward/record.url?scp=79960961369&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79960961369&partnerID=8YFLogxK

U2 - 10.1007/s00221-011-2755-3

DO - 10.1007/s00221-011-2755-3

M3 - Article

VL - 212

SP - 505

EP - 516

JO - Experimental Brain Research

JF - Experimental Brain Research

SN - 0014-4819

IS - 4

ER -