The human forearm is made up of tubular long bones. There are two of them. In the forearm is the ulna and radius. They are bent so that, being nearby, they are connected only by their ends. On its entire extent, there is space between them. The ulnar and radius include the body (diaphysis) and the ends (pineal glands). On the pineal glands are articular surfaces.
Through some articular surfaces, a connection is made to the humerus. Others are designed to articulate with wrist segments.
The ulnar and radius in their length have a trihedral shape. There are three edges and three surfaces. One surface is directed forward, the second - backward. The third - at the ulna - inside, and at the radius - outside.
Of all three edges, one is sharp. It separates the posterior and anterior surfaces, facing the adjacent bone, limiting the space between the bones. In this regard, it has another 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.
So, the radius is located on the outside of the forearm. The lower pineal gland of this segment is more massive. At the upper 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 radius is also endowed with a special tuberosity - the place of attachment of the biceps brachii.
The radius is characterized by a slightly widened lower end. There is a notch on the inside. The ulnar bone enters it.
On the opposite side there is an awl-shaped process running downward. The lower surface has a concave carpal joint surface. Using the protrusion, it is divided into two sections for the lunate and scaphoid.
In traumatological practice, various injuries of the bones of the forearm are found. Among them, experts distinguish more or less common. So, as a result of a direct (blow to the forearm) or indirect (fall on the arm) injury, a diaphyseal fracture can occur in both bones of the forearm. In this case, small fragments of segments are formed, the position of which can vary. Due to the contraction of the membrane located between the bones, the fragments, as a rule, approach each other.
A fracture of the radius with a shift is characterized by a certain shortening of the forearm. The patient supports a damaged limb with a healthy hand. The mobility of the fragments provokes sharp pain at the time of probing the site, lateral compression of the forearm section removed from the site of injury and under axial load.
When falling on an outstretched arm, as a rule, a fracture of the radial head occurs. In this case, pain appears in the region of the
elbow joint , swelling occurs, and it is difficult for the patient to move the limb. Due to the fact that this type of damage includes several types, to establish an accurate diagnosis, it is necessary to conduct an x-ray examination.