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Journal of Aging Research
Volume 2012, Article ID 629637, 6 pages
Clinical Study

Intramuscular Adipose Tissue, Sarcopenia, and Mobility Function in Older Individuals

1Department of Physical Therapy, University of Utah, 520 Wakara Way, Salt Lake, UT 84108, USA
2Department of Radiology, University of Utah, 30 N 1900 E, Salt Lake, UT 84132, USA

Received 1 August 2011; Accepted 13 November 2011

Academic Editor: Stéphane Michel Schneider

Copyright © 2012 Robin L. Marcus et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Objective. Intramuscular adipose tissue (IMAT) and sarcopenia may adversely impact mobility function and physical activity. This study determined the association of locomotor muscle structure and function with mobility function in older adults. Method. 109 older adults with a variety of comorbid disease conditions were examined for thigh muscle composition via MRI, knee extensor strength via isometric dynamometry, and mobility function. The contribution of strength, quadriceps lean tissue, and IMAT to explaining the variability in mobility function was examined using multivariate linear regression models. Results. The predictors as a group contributed 27–45% of the variance in all outcome measures; however, IMAT contributed between 8–15% of the variance in all four mobility variables, while lean explained only 5% variance in only one mobility measure. Conclusions. Thigh IMAT, a newly identified muscle impairment appears to be a potent muscle variable related to the ability of older adults to move about in their community.