A method of monitoringtarget tissue of a biological skeletalsystem. The method comprises applyinga mechanical excitation to aportion of the biological skeletal systemto generate a mechanical wavethat passes through the target tissue,the target tissue modulating the mechanicalwave to produce a responseof the target tissue to the mechanicalwave, measuring the response； and determiningstructural or functional statusof the target tissue from the response.A system for applying themethod is also provided.
