Understanding the Borders of the Body of the Radius
The body of the radius, like many other bones, has a unique curve that causes it to protrude outward on the thumb side of the arm. This curved body consists of three distinct borders, namely the volar, dorsal, and interosseous borders. It is worth noting that some medical texts and physicians may refer to the volar and dorsal borders as the anterior and posterior borders, respectively.
The volar border of the radius starts at the radial tuberosity and extends to connect with the styloid process. On the other hand, the dorsal border begins at the neck of the radius and connects to the back of the styloid process. The interosseous border, initially less defined at the neck, gradually becomes sharper as it extends towards the wrist. It serves the purpose of separating the volar and dorsal borders.
Body Surfaces
When examining the body of the radius, it is evident that there are three distinct surfaces. The first one, known as the volar surface, is initially concave and then gradually becomes wider and flatter towards the wrist. Moving on to the dorsal surface, it can be divided into three sections: the upper third is smooth and convex, the middle section is broad and slightly concave, and the final area combines both characteristics, being broad and convex. The last surface, referred to as the lateral surface or the “convexity of the radius,” is completely convex and curves outward.