Botten van de bovenste ledemaat: Radius

The radius is the lateral forearm bone that runs parallel to the ulna and joins it proximally at the radial notch and distally via the ulnar notch.

It has a nail-shaped head and a curvy shaft that ends in a pointed projection called the radial styloid process.

At the proximal end, the head joins with the humeral capitulum and the ulna, forming the elbow joint. Rotation of the radial head enables forearm movement while turning the palm upwards or downwards. During flexing of the arm, the head moves into the radial fossa of the humerus.

Just below the radial head, a narrow neck extends to the rough radial tuberosity that anchors the bicep muscles of the arm.

At the distal end, the radial styloid process joins with the wrist bones forming the radiocarpal or wrist joint.

The styloid process stabilizes the wrist joint movement via a short and a long radiolunate ligament to limit the lateral rotation of the wrist.