By means of some articular surfaces, a connection with the humerus is made. Others are designed for articulation with segments of the wrist.
The ulna and radius in its entire lengthhave a trihedral shape. There are three edges and three surfaces. One surface is directed forward, the other is facing back. The third - at the ulna - to the inside, and at the radial bone - to the outside.
Of all three edges sharp one.It divides the posterior and anterior surfaces, facing the adjacent bone, limiting the space between the bones. In this regard, it has one more name - the interosseous region.
It should be noted that the components of the skeleton of the forearm, in addition to common features, have distinctive features.
Thus, the radius is located on the outsideforearm. The lower epiphysis of this segment is more massive. At the top end is the head of the bone. There is a small depression in it. The edge of the head has an articular circumference.
Just below the head is the neck. The radial bone is also endowed with a special tuberosity, the place of attachment of the biceps brachial muscle.
The radius of the radialis differs somewhat by its widened lower end. On the inside there is a tenderloin. It comes in the ulna.
On the opposite side there isstyloid process, going downwards. The lower surface has a concave carpal articular surface. Using a ledge, it is divided into two sections for the semilunar and scaphoid bone.
Fracture of radius with displacementis characterized by some shortening of the forearm. The patient supports the injured limb with a healthy arm. Mobility of the fragments provokes a sharp pain at the moment of palpation of the site, lateral compression of the forearm site removed from the injury site and under the axial load.