radial notch

At the posterior attachment the ligament widens to reach above and below the radial notch.

Its lateral surface presents a narrow, oblong, articular depression, the radial notch.

Both genera share leaves with a radial notch from the circumference to the petiole (leaf stem) in the centre.

During pronation the radius is rotated so that the head's major axis reaches the radial notch on the ulna.

The fibrocartilage on the upper part of the ligament is continuous with the hyaline cartilage of the radial notch.

At the elbow, it joins with the capitulum of the humerus, and in separate region, the ulna at the radial notch.

It lodged in the radial notch, wedged as tight as a doorstop in the hypercarbon.

The leaves are round, with a radial notch in Nymphaea and Nuphar, but fully circular in Victoria.

The head is cylindrical to allow axial rotation of the radius, thus to articulate with the annular ligament and the radial notch on the ulna.

The quadrate ligament is a fibrous band attached to the inferior border of the radial notch on the ulna and to the neck of the radius.

The upper extremity presents two curved processes, the olecranon and the coronoid process; and two concave, articular cavities, the semilunar and radial notches.

Below, it is fixed to the upper and lateral margins of the olecranon, to the posterior part of the annular ligament, and to the ulna behind the radial notch.

A thickened band which extends from the inferior border of the anular ligament below the radial notch to the neck of the radius is known as the quadrate ligament.

The radial notch is a narrow, oblong, articular depression on the lateral side of the coronoid process; it receives the circumferential articular surface of the head of the radius.

Less distinct than the ulnar collateral ligament, this ligament blends with the annular ligament of the radius and its margins are attached near the radial notch of the ulna.

The anular ligament (orbicular ligament) is a strong band of fibers that encircles the head of the radius, and retains it in contact with the radial notch of the ulna.

The circumference of the head is smooth; it is broad medially where it articulates with the radial notch of the ulna, narrow in the rest of its extent, which is embraced by the annular ligament.

The anular ligament is attached by both its ends to the anterior and posterior margins of the radial notch of the ulna, together with which it forms the articular surface that surrounds the head and neck of the radius.

The proximal radioulnar articulation (superior radioulnar joint) is a synovial trochoid or pivot joint between the circumference of the head of the radius and the ring formed by the radial notch of the ulna and the annular ligament.

The quadrate ligament reinforces the inferior part of the capsule of the elbow joint and contributes to joint stability by securing the proximal radius against the radial notch and by restricting excessive supination (10-20 restriction) and, to a lesser degree, pronation (5-8 ).

The proximal radioulnar joint is similarly derived in higher primates in the location and shape of the radial notch on the ulna; the primitive form being represented by New World monkeys, such as the howler monkey, and by fossil catarrhines, such as Aegyptopithecus.

The bony surfaces would of themselves constitute an enarthrosis and allow movement in all directions, were it not for the annular ligament, by which the head of the radius is bound to the radial notch of the ulna, and which prevents any separation of the two bones laterally.

On its upper part is an oblique ridge, which runs from the dorsal end of the radial notch, downward to the dorsal border; the triangular surface above this ridge receives the insertion of the Anconæus, while the upper part of the ridge affords attachment to the supinator.

The interosseous crest (crista interossea; external or interosseous border) begins above by the union of two lines, which converge from the extremities of the radial notch and enclose between them a triangular space for the origin of part of the Supinator; it ends below at the head of the ulna.