We measured bone density and volume at different levels of the normal lower leg by computed tomography. The fibular mass at each transverse level was 18-20 percent of the total bone mass. Tibial masses at all the levels correlated with distal femoral and proximal tibial masses. Summing the fibular and tibial masses augmented the correlations. The mass values varied substantially at different levels of the lower leg, being highest in the midshaft. We hypothesize that the lower extremity is a biomechanical continuum where the distribution of the bone mass corresponds to the functional demands, indicating that the fibula is not "dispensable."