1. Covariance of isometric and dynamic arm contractions: multivariate genetic analysis.
- Author
-
De Mars, Gunther, Thomis, Martine A. I., Windelinckx, An, Van Leemputte, Marc, Maes, Hermine H., Blimkie, Cameron J., Claessens, Albrecht L., Vlietinck, Robert, and Beunen, Gaston
- Subjects
MUSCLE strength ,ELBOW ,GENOTYPE-environment interaction ,TWINS ,CAUCASIAN race ,ARM ,COMPARATIVE studies ,RESEARCH methodology ,MEDICAL cooperation ,MULTIVARIATE analysis ,MUSCLE contraction ,RESEARCH ,EVALUATION research - Abstract
The purpose of the present study was to examine genetic and environmental contributions to individual differences in maximal isometric, concentric and eccentric muscle strength and muscle cross-sectional area (MCSA) of the elbow flexors. A generality versus specificity hypothesis was explored to test whether the 4 strength variables share a genetic component or common factors in the environment or whether the genetic/environmental factors are specific for each strength variable. The 4 variables under study were measured in 25 monozygotic and 16 dizygotic male Caucasian twin pairs (22.4 +/- 3.7 years). The multivariate genetic analyses showed that all 4 variables shared a genetic and environmental component, which accounted for 43% and 6% in MCSA (h2 = 81%), 47% and 20% in eccentric (h2 = 65%), 58% and 4% in isometric (h2 = 70%) and 32% and 1% in concentric strength (h2 = 32%) respectively. The remaining variation was accounted for by contraction type specific and muscle cross-sectional area specific genetic and environmental effects, which accounted for 38% and 14% in MCSA, 18% and 15% in eccentric, 12% and 26% in isometric and 0% and 67% in concentric strength respectively. This exploratory multivariate study suggests shared pleiotropic gene action for MCSA, eccentric, isometric and concentric strength, with a moderate to high genetic contribution to the variability of these characteristics. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF