Differential load impact upon arm tremor dynamics and coordinative strategy between postural holding and position tracking

Ing-Shiou Hwang, Yi Ching Chen, Pei Shan Wu

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

This study contrasted the effects of load characteristics on coordinative strategies between postural holding and position tracking. Fifteen healthy adults conducted postural holding and sinusoidal tracking with the index finger while manipulated loads (0, 50, and 100 g) were superimposed on an outstretched arm. Oscillatory activities in the upper limb, target curve, and index position were monitored. The results showed that the effect of loading upon tremor structure was segment-dependent in relation to the task being performed. Load addition resulted in a task-dependent compensatory modulation of tremors between the distal segments (hand and finger), despite tremor augmentation in the proximal segments (forearm or arm). In comparison with postural holding, manual tracking exhibited a greater release of tremor coupling in the finger-hand complex, but a stronger tremor coupling in the forearm-arm complex secondary to added mass. Tremor reorganization in the upper limb following load addition could be characterized by changes in the primary principal component of segment tremors, which was more downward modulated during loaded tracking than loaded holding. Functionally, adding weight reduced tremor-relevant tracking error, while an opposing load did not add to holding steadiness. In summary, tremors associated with loaded holding and tracking were differently reorganized, in support of the hypothesis that coordination strategies against destabilizing loads for postural task and movement task are fundamentally dissimilar.

Original languageEnglish
Pages (from-to)945-957
Number of pages13
JournalEuropean Journal of Applied Physiology
Volume105
Issue number6
DOIs
Publication statusPublished - 2009 Jan 23

Fingerprint

Tremor
Arm
Fingers
Forearm
Upper Extremity
Hand
Weights and Measures

All Science Journal Classification (ASJC) codes

  • Orthopedics and Sports Medicine
  • Physiology (medical)
  • Public Health, Environmental and Occupational Health

Cite this

@article{778f17ed14c54d15987d4e28a2d0f0c0,
title = "Differential load impact upon arm tremor dynamics and coordinative strategy between postural holding and position tracking",
abstract = "This study contrasted the effects of load characteristics on coordinative strategies between postural holding and position tracking. Fifteen healthy adults conducted postural holding and sinusoidal tracking with the index finger while manipulated loads (0, 50, and 100 g) were superimposed on an outstretched arm. Oscillatory activities in the upper limb, target curve, and index position were monitored. The results showed that the effect of loading upon tremor structure was segment-dependent in relation to the task being performed. Load addition resulted in a task-dependent compensatory modulation of tremors between the distal segments (hand and finger), despite tremor augmentation in the proximal segments (forearm or arm). In comparison with postural holding, manual tracking exhibited a greater release of tremor coupling in the finger-hand complex, but a stronger tremor coupling in the forearm-arm complex secondary to added mass. Tremor reorganization in the upper limb following load addition could be characterized by changes in the primary principal component of segment tremors, which was more downward modulated during loaded tracking than loaded holding. Functionally, adding weight reduced tremor-relevant tracking error, while an opposing load did not add to holding steadiness. In summary, tremors associated with loaded holding and tracking were differently reorganized, in support of the hypothesis that coordination strategies against destabilizing loads for postural task and movement task are fundamentally dissimilar.",
author = "Ing-Shiou Hwang and Chen, {Yi Ching} and Wu, {Pei Shan}",
year = "2009",
month = "1",
day = "23",
doi = "10.1007/s00421-009-0981-1",
language = "English",
volume = "105",
pages = "945--957",
journal = "European Journal of Applied Physiology",
issn = "1439-6319",
publisher = "Springer Verlag",
number = "6",

}

Differential load impact upon arm tremor dynamics and coordinative strategy between postural holding and position tracking. / Hwang, Ing-Shiou; Chen, Yi Ching; Wu, Pei Shan.

In: European Journal of Applied Physiology, Vol. 105, No. 6, 23.01.2009, p. 945-957.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Differential load impact upon arm tremor dynamics and coordinative strategy between postural holding and position tracking

AU - Hwang, Ing-Shiou

AU - Chen, Yi Ching

AU - Wu, Pei Shan

PY - 2009/1/23

Y1 - 2009/1/23

N2 - This study contrasted the effects of load characteristics on coordinative strategies between postural holding and position tracking. Fifteen healthy adults conducted postural holding and sinusoidal tracking with the index finger while manipulated loads (0, 50, and 100 g) were superimposed on an outstretched arm. Oscillatory activities in the upper limb, target curve, and index position were monitored. The results showed that the effect of loading upon tremor structure was segment-dependent in relation to the task being performed. Load addition resulted in a task-dependent compensatory modulation of tremors between the distal segments (hand and finger), despite tremor augmentation in the proximal segments (forearm or arm). In comparison with postural holding, manual tracking exhibited a greater release of tremor coupling in the finger-hand complex, but a stronger tremor coupling in the forearm-arm complex secondary to added mass. Tremor reorganization in the upper limb following load addition could be characterized by changes in the primary principal component of segment tremors, which was more downward modulated during loaded tracking than loaded holding. Functionally, adding weight reduced tremor-relevant tracking error, while an opposing load did not add to holding steadiness. In summary, tremors associated with loaded holding and tracking were differently reorganized, in support of the hypothesis that coordination strategies against destabilizing loads for postural task and movement task are fundamentally dissimilar.

AB - This study contrasted the effects of load characteristics on coordinative strategies between postural holding and position tracking. Fifteen healthy adults conducted postural holding and sinusoidal tracking with the index finger while manipulated loads (0, 50, and 100 g) were superimposed on an outstretched arm. Oscillatory activities in the upper limb, target curve, and index position were monitored. The results showed that the effect of loading upon tremor structure was segment-dependent in relation to the task being performed. Load addition resulted in a task-dependent compensatory modulation of tremors between the distal segments (hand and finger), despite tremor augmentation in the proximal segments (forearm or arm). In comparison with postural holding, manual tracking exhibited a greater release of tremor coupling in the finger-hand complex, but a stronger tremor coupling in the forearm-arm complex secondary to added mass. Tremor reorganization in the upper limb following load addition could be characterized by changes in the primary principal component of segment tremors, which was more downward modulated during loaded tracking than loaded holding. Functionally, adding weight reduced tremor-relevant tracking error, while an opposing load did not add to holding steadiness. In summary, tremors associated with loaded holding and tracking were differently reorganized, in support of the hypothesis that coordination strategies against destabilizing loads for postural task and movement task are fundamentally dissimilar.

UR - http://www.scopus.com/inward/record.url?scp=63049116478&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=63049116478&partnerID=8YFLogxK

U2 - 10.1007/s00421-009-0981-1

DO - 10.1007/s00421-009-0981-1

M3 - Article

VL - 105

SP - 945

EP - 957

JO - European Journal of Applied Physiology

JF - European Journal of Applied Physiology

SN - 1439-6319

IS - 6

ER -