Significant correlations between muscle cross-sectional area and bone were found at all section levels investigated. The strongest correlation for compression was observed in the sections at 14% (correlation coefficient r = 0.74), where 4.10 ± 0.46 cm2 bone, on average, was related to 100 cm2 muscle. The compression index (CI) at the 14% level was independent of the tibia length. Interestingly, the 15 athletes had significantly greater CIs than the control subjects.