between the top of the leg portion and the foot and heel portions finally it should be noted that the configuration of the leg portion of the preferred embodiments of the present invention particularly the relatively high area moment of inertia of the cross section of the leg portion 24 taken along a longitudinal axis 62 and the relatively low area moment of inertia of the same cross section taken along a transverse axis 64 provides a very rigid structure about the axis 62 but substantial non energy absorbing compliance about axis 64 which gives the prosthetic foot and leg some rotation capabilities as if it had an ankle joint this compliance is of course limited though is sufficient to significantly enhance the performance thereof a second unit has also been fabricated and tested this unit also being fabricated using epoxy impregnated carbon filament the second unit also has a width of two inches but a slightly thicker leg of 0 32 inches the second unit has a total length of 5 75 inches a leg length of 13 inches a maximum stress for 135 pound load of 23 684 psi in flexing and 316 psi in sheer the vertical spring rate of the second unit is 772 pounds per inch with the torsional spring rate.