Muscle size, strength, and bone geometry in the upper limbs of young and old men

• Published in: The journals of gerontology. Series A, Biological sciences and medical sciences Biological sciences and medical sciences, 2002-07, Vol.57 (7), p.M455-M459
• Main Authors: Klein, C S, Allman, B L, Marsh, G D, Rice, C L
• Format: Article
• Language: English
• Subjects: Adult; Age Factors; Aged; Aging; Arm - anatomy & histology; Arm - physiology; Bones; Humans; Humerus - anatomy & histology; Male; Men; Muscle, Skeletal - anatomy & histology; Muscle, Skeletal - physiology; Muscular system; Radius - anatomy & histology; Ulna - anatomy & histology
• ISSN: 1079-5006; 1758-535X
• DOI: 10.1093/gerona/57.7.M455

Bone loss in old men is associated with a decrease in muscle mass and strength. However, the influence of muscle size and strength on age-related changes in bone geometry has not been comprehensively described. Methods. Men in their third (group I, 23 +/- 3 y, n = 20), eighth (group II, 77 +/- 1 y, n = 10), and ninth (group III, 86 +/- 4 y, n = 13) decades of age were studied. The cross-sectional area (CSA) of the elbow flexors, elbow extensors, and forearm muscles, the total area (TA), cortical area (CA), and medullary area (MA) of the midhumerus, and distal third of the radius and ulna (n = 7 group II; n = 6 group III) were measured with magnetic resonance imaging. The maximal isometric strength (MVC) of the elbow flexors and elbow extensors was also determined. The CSA and MVC of the arm muscles (elbow flexors plus elbow extensors) were less in group II (-17% and -22%) and III (-32% and -39%), respectively, compared to group I. However, forearm CSA was less (-21%) in group III only. The TA and MA of all bones were greater in the older groups. The CA of the humerus (-14%) and ulna (-10%), but not the radius, was less in group III compared to group I, whereas CA was unchanged in group II. Stepwise multiple linear regression determined that arm muscle CSA (r = 0.52, p