A method of determining a condition of bone structure in a living organism includes impacting a bone to induce vibration in multiple modes having a resonance frequency in a range of about 400 Hz to about 1000 Hz, detecting at least one modal vibration response of the bone for the at least one mode of vibration, and analyzing the at least one modal vibration response to determine a modal vibration characteristic of the bone. A system for determining a condition of bone structure in a living organism includes a force input device configured to impact a bone to induce vibration having a resonance frequency of about 400 Hz to about 1000 Hz, at least one sensor configured to sense at least one modal vibration response, and a computer configured to collect modal vibration response data and analyze the modal vibration response data to determine a vibration characteristic of the bone.