A micro drop system consisting of an impactor supported by twin parallelogram linkages was designed to enable guided drop height as low as 10mm. The system has been used to measure dynamic compressive response of human cancellous bone for strain rates of 135/s, 150/s and 175/s. The percentage variation of Young’s modulus from its mean value of 0.083GPa obtained at these strain rates is 54.5%, which is significant, suggesting that bones become stiffer during severe impacts.