Thigh composition in young and elderly men determined by computed tomography

Authors

  • T. J. Overend,

    1. *Centre for Activity and Ageing (affiliated with the Faculty of Kinesiology at The University of Western Ontario and the Lawson Research Institute at St. Joseph's Health Centre), Faculty of Kinesiology
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  • D. A. Cunningham,

    Corresponding author
    1. *Centre for Activity and Ageing (affiliated with the Faculty of Kinesiology at The University of Western Ontario and the Lawson Research Institute at St. Joseph's Health Centre), Faculty of Kinesiology
    2. †Department of Physiology, University of Western Ontario, London, Ontario, Canada, N6A 3K7
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  • D. H. Paterson,

    1. *Centre for Activity and Ageing (affiliated with the Faculty of Kinesiology at The University of Western Ontario and the Lawson Research Institute at St. Joseph's Health Centre), Faculty of Kinesiology
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  • M. S. Lefcoe

    1. ‡Department of Diagnostic Radiology and Nuclear Medicine, University of Western Ontario, London, Ontario, Canada, N6A 3K7
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2 Centre for Activity and Ageing, The University of Western Ontario, London, Ontario, Canada, N6A 3K7.

Abstract

Summary. Computed tomography (CT) was used to quantify components of the thigh in young (n= 13) and elderly (n= 11) men. Cross-sectional areas (CSA) of the total limb, total muscle plus bone, quadriceps compartment, hamstring compartment and bone were measured at each of five scan sites along the length of the thigh. Non-muscle tissue (NMT) areas within the muscle compartments were measured using changes in density based on Hounsfield units. Skin plus subcutaneous fat areas and quadriceps and hamstring lean muscle areas were calculated by subtraction. Geometric formulae were used to calculate related volumes for each thigh component. Volumes were also predicted from regression equations employing thigh length and component CSA from single mid-limb CT scans. The results showed that while total thigh CSA was not different in elderly men, they had significantly smaller total muscle plus bone (13-0%), and quadriceps (26.4%), and hamstring (17.9%) muscle areas. The elderly men also had significantly greater CSA for skin plus subcutaneous fat (37-6%), and for NMT in the quadriceps (59.4%) and hamstring (127.3%) muscle compartments. These results suggest that comparisons of relative leg muscle strength between young and elderly men may be misleading due to the decrease in actual muscle tissue associated with ageing. Appropriate quantification of muscle size and CSA must be carried out before such comparisons can be meaningful.

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