Activation frequency is often used as a measure of basic multicellular unit
(BMU) activity in cancellous bone. However, activation frequency expresses
the rate of BMU appearance in a histologic slide and not the rate of origi
nation, which is a more physiologic indicator of remodeling activity and is
necessary for the development of BMU-level bone remodeling simulations. Us
ing identical assumptions to those for calculating the activation frequency
, it is shown that the origination frequency in cancellous bone is equal to
the activation frequency divided by the total distance traveled by the BMU
and its width. (C) 1999 by Elsevier Science Inc. All rights reserved.