Document Detail


The curvature and variability of wrist and arm movements.
MedLine Citation:
PMID:  20383764     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The control of wrist rotations is critical for normal upper limb function, yet has received little attention. In this study, we characterized path shape of wrist rotations in order to better understand the biomechanical and neural factors governing their control. Subjects performed step-tracking wrist rotations in eight directions "at a comfortable speed" and "as fast as possible." For comparison, we also analyzed subjects' arm movement paths in a similar task. We found significant differences between wrist and arm movements. Wrist paths were more curved and more variable than arm paths (p < 0.001). The increased curvature and variability can be explained in part by neuromuscular noise (in actuation and sensing) which is known to increase from proximal to distal in the upper limb. The curvature and variability of wrist paths increased with movement speed (p < 0.001), further implicating (signal-dependent) noise. However, noise cannot explain all of our observations. For example, we found that wrist rotations exhibit a systematic pattern: outbound and inbound paths between the same two targets tend to veer to opposite sides of a straight line. We provide evidence indicating that this type of systematic pattern is not likely caused by noise or other neural causes, but may be explained by the unique biomechanics of the wrist.
Authors:
Steven K Charles; Neville Hogan
Related Documents :
11844584 - Comparison between macaques' and humans' kinematics of prehension: the role of morpholo...
17355034 - Bimanual curvature discrimination of hand-sized surfaces placed at different positions.
3239614 - Upper extremity range of motion and isokinetic strength of the internal and external sh...
9860274 - Coordination among the body segments during reach-to-grasp action involving the trunk.
22117234 - Improvement of external quantum efficiency depressed by visible light-absorbing hole tr...
16583764 - Does perceptual belongingness affect lightness constancy?
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-04-11
Journal Detail:
Title:  Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale     Volume:  203     ISSN:  1432-1106     ISO Abbreviation:  Exp Brain Res     Publication Date:  2010 May 
Date Detail:
Created Date:  2010-05-04     Completed Date:  2010-08-02     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0043312     Medline TA:  Exp Brain Res     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  63-73     Citation Subset:  IM    
Affiliation:
Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA. scharles@alum.mit.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Analysis of Variance
Arm / physiology*
Biomechanics
Female
Humans
Male
Motor Activity / physiology*
Rotation
Task Performance and Analysis
Wrist / physiology*
Young Adult

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Reach adaptation to explicit vs. implicit target error.
Next Document:  Is nitric oxide a mediator of the effects of low-intensity electrical stimulation on bone in ovariec...