The kinematical model of wave propagation in three-dimensional excitable media is formulated. As an example, it is used to investigate properties of scroll rings in such media. The analysis reveals that collapse or expansion of a scroll ring result from the resonant interactions between individual w
Three-dimensional kinematics of glenohumeral elevation
โ Scribed by Dr. K.-N. An; A. O. Browne; S. Korinek; S. Tanaka; B. F. Morrey
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 541 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0736-0266
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โฆ Synopsis
To help resolve longstanding uncertainties about kinematics of the shoulder, we studied three-dimensional glenohumeral joint motion during arm elevation. A magnetic tracking system was used to monitor the three-dimensional orientation of the humerus with respect to the scapula. Appropriate coordinate transformations were then performed for the calculation of glenohumeral joint rotation based on the defined Eulerian angle. The effects of the plane of elevation and the humeral rotation on the magnitude of arm elevation were documented. The maximum humeral elevation at the glenohumeral joint took place in a plane anterior to the scapular plane. Maximum elevation in all planes anterior to the scapular plane required external axial rotation of the humerus. Conversely, internal axial rotation was necessary for maximum elevation posterior to the scapular plane. Quantifying the obligatory axial rotation explains the relationship of internal and external rotation with maximum elevation.
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