Document Detail

Performance of elbow tracking under constant torque disturbance in normotonic stroke patients and normal subjects.
MedLine Citation:
PMID:  12446160     Owner:  NLM     Status:  MEDLINE    
OBJECTIVE: In this study, the influences of externally imposed constant torque on the voluntary elbow movements of stroke and normal subjects were investigated quantitatively. BACKGROUND: Muscle weakness, spasticity and incoordination are the major factors that interfere with stroke patient's limb functions. Imposing external torque disturbance may worsen the motor performance. This experiment was designed to investigate the effects of small constant external torque on the performance of voluntary elbow movements. METHODS: Tracking of a ramp-and-hold angle trajectory in the direction of extension was used as the main task for performance assessment. Each subject repeated the same tracking movement six times in each of three loading conditions: no, assistive or resistive loading. Five normal and six stroke subjects were recruited for this study. We used parameters extracted from movement trajectory and processed electromyograms as the performance indicators. RESULTS: For normal subjects, there was no difference in the tracking performance in the three loading conditions. For stroke patients, the affected side had inferior performance to the healthy side in the free loading condition and the difference diminished in assistive and resistive loading conditions as the performance of the affected side improved. Integrated electromyograms of biceps or triceps did not show significant changes in different loading conditions. CONCLUSIONS: Small externally imposed constant torque, either resistive or assistive, may improve motor performance of affected elbows in stroke patients. RELEVANCE: Most of the currently available prostheses are passive devices, aiming at providing better support and improving stability. The results of the current study imply that an active prosthetic device that applies a small constant torque to the hemiparetic elbow can improve its motor performance in stroke patients. The direction of external torque is to assist the weaker side of the antagonistic muscle pair.
M S Ju; C C K Lin; J R Chen; H S Cheng; C W Lin
Publication Detail:
Type:  Clinical Trial; Controlled Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Clinical biomechanics (Bristol, Avon)     Volume:  17     ISSN:  0268-0033     ISO Abbreviation:  Clin Biomech (Bristol, Avon)     Publication Date:    2002 Nov-Dec
Date Detail:
Created Date:  2002-11-26     Completed Date:  2003-01-16     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  8611877     Medline TA:  Clin Biomech (Bristol, Avon)     Country:  England    
Other Details:
Languages:  eng     Pagination:  640-9     Citation Subset:  IM    
Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC.
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MeSH Terms
Elbow / physiopathology*
Middle Aged
Muscle Contraction*
Muscle Tonus
Muscle, Skeletal / physiopathology*
Muscular Diseases / etiology,  physiopathology*
Reproducibility of Results
Sensitivity and Specificity
Stress, Mechanical
Stroke / complications,  physiopathology*
Task Performance and Analysis

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

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