Development of a Position-Specific Index of Muscle Strength to be Used in Stroke Evaluation
Abstract
Moriello C, Mayo NE. Development of a position-specific index of muscle strength to be used in stroke evaluation.
Objective
To develop a position-specific index of muscle strength for individuals with stroke.
Design
Cross-sectional design.
Setting
A major teaching hospital in a Canadian urban city.
Participants
Sixty-three patients with poststroke onset between 3 and 12 months.
Interventions
Not applicable.
Main Outcome Measure
The muscle strength of the lower-extremity muscles was tested bilaterally in multiple positions using hand-held dynamometry.
Results
A principal components analysis resulted in grouping the muscles of the affected and unaffected sides of the gravity related and gravity eliminated positions into 5 indices. The 5 indices were moderately to highly correlated (r2 range, .59−.81) with each other and so were combined into 1 global index. The gravity related muscle strength on the affected side was, on average, 85% of the unaffected side (range, 37%–157%); the gravity eliminated muscle strength of the affected side was, on average, 92% of the unaffected side (range, 53%–121%).
Conclusions
This study resolves the methodologic issue of how to summarize multiple data points that relate to one construct, namely, strength of different muscle groups assessed in several positions.
Division of Clinical Epidemiology, Royal Victoria Hospital, Montreal, QC, Canada; and School of Physical and Occupational Therapy, McGill University, Montreal, QC, Canada.
Reprint requests to Nancy E. Mayo, PhD, Div of Clinical Epidemiology, Ross Pavilion R4.29, Royal Victoria Hospital Site, 687 Pine Ave W, Montreal, QC H3A 1A1, Canada
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated.
ABSTRACT