In viva bone behaviour predictions with respect to altered loading conditions, im@tts, and endq~ostheses are highly desirable to avoid untoward ejkts such as implant loosening and breahage. This hnowle&e does not rebate only to the result but also to the mechanssms of bone a&nation and bone growth, Since bone growth is assumed to be determined essentially by the loading history, the morphology of the human femoral m&ha. region was adysed to extract those loading cases re$wnsiblc~ the ncr~al cross-sectional geometry. This was achieved by the application of computer-aided optimization (GAO), a procedure sup@menting a finite element analysis which allows@ simulation of aakpive bone growth. A simulated load was applied to a cylinder, and the resulting changes in geometry were compared with the geometry of three ex vivo samples. Apparent~, standard hnuiing cases abme (axial loading, bending, torsion), or at coruecutive or simultaneous application, did not yield the characteristic morphology of the f-al shaj region Only the inkoduction of the aaductor musck fice in various combinations with other start&d Lnrdingr resulted in f-al mid-sha$ geometries comparable with the ex vivo specimens.