Relationships of Body Size, Segmental Dimensions, and Ponderal Equivalents to Muscular Strength in High-Strength and Low-Strength Subjects

Abstract

There are conflicting results in prior studies concerning the relationships among body size, muscle size, and muscular strength. The purpose of the present study was to evaluate how body size, body shape, and segmental dimensions related to individual differences in muscular strength. Subjects were tested on four dynamic measures of strength and then classified into one of two groups as high strength (HS; N = 21) and low strength (LS; N = 21), Individual differences in strength were then related to body composition and segmental anthropometry. Strength was assessed during high-resistance, low-velocity standing squat and supine bench press with an isokinetic dynamometer, and during seated bench press and knee extension with a hydraulic resistance dynamometer. Anthropometry and body composition included 11 girths, six fatfolds, predicted fat-free mass (FFM), thigh and upper arm volume, muscle + bone cross-sectional area (CSA), and the Behnke Ponderal Somatogram (PSom) body profiling system. There was a 21.3% difference in strength between HS and LS (p < 0.05), but no significant differences in age, stature, and fatfolds MANOVA revealed that seven of 11 girth components of PSom were larger for HS (p < 0.05). The correlations between strength vs body mass, FFM, thigh and upper arm volume, and CSA and fatfolds in HS and LS ranged from r = 0.52 to 0.56 (r = 0.70 to 0.70 when corrected for restriction of range). We conclude that individual differences in muscular strength are poorly related to various measures of body size and segmental body dimensions.