-Bohler's angle also called as the Tuber joint angle, measures the angular relationship between talus and calcaneum. This angle is formed by two lines . first line is drawn from the posteriosuperior margin of the calcaneal tuberosity through the tip of the posterior facet of the subtalar joint. second line is drawn from the tip of the posterior facet through the superior margin of the anterior process of the calcaneum.
-Normally this angle ranges between 20 and 40 degrees.
-Flattening of this angle is a classic x-ray sign of depressed fracture of calcaneum.
P.S : The image is not my original work and has been taken from the wikimedia commons project and the author is Gilo1969.