Each of them is composed of a series of aponeurotic membranes, longitudinal, parallel, horizontal, and at about one line’s distance from each other.

In the distal half of this muscle there are three distinct parts; the anterior and posterior edges are fleshy and the central part is aponeurotic.

The amount of displacement depends upon the level of the fracture, and the extent to which the aponeurotic expansion of the triceps is torn.