Clavicle

Clavicle, right. Gray, Henry.

This is so, so, from Human Anatomy For Artists: The Elements of Form, by Eliot Goldfinger.

The clavicle articulates medially with the sternum, and laterally with the inner border of the acromion of the scapula.

Articulation at the sternum is the only bony connection between entire shoulder girdle and the rest of the skeleton.

Clavicle appears straight when viewed from the front; S-curved when seen from above.

Begins at thorax, where neck meets the chest, and end at the middle of the top of the shoulder (the midfrontal plane of the body).

Medial two-thirds projects forward (an anterior curve)(and is rounded), while the lateral third has a short, tight, backward curve. Clavicles together form “archer’s bow” from the top (view)(and is flattened).

Clavicle, right. Gray, Henry.

The acromial is the highest point of the shoulder, slightly higher than acromion process of the scapula– May be so prominent that it protrudes as a round bump in life. In contrast the medial end sits slightly forward of anterior surface of the sternum.

The pit of the neck, or the suprasternal notch, is formed between the pair of medial ends of the clavicle (about an inch apart).

Front and top surface of clavicle usually visible in life. While laterally, muscle fibers often obscure the form of the clavicle.

Varying in size, about one-fourth of the way in from the lateral end of the clavicle, is, sometimes a bony landmark. On this anterior surface, is the bend where the long anterior curve meets the short posterior curve), and is where the deltoid originates, in part from this projection.

At rest the clavicle may appear level or slight raised laterally. Sometimes it may be downward, therefore causing the neck to look longer.

When the shoulder is raised, the hollow behind the middle third, the supraclavicular fossa, deepens.

Both shoulders pulled back, the clavicle rest along the cylindrical base of the neck (explaining the S-shaped curves).

Arms raised, clavicle is less prominent, and is concealed in a groove laterally.

“In this position, appreciating its S-shaped curvature provides an important key to understanding the way the neck, shoulder, and upper chest muscles meet at the base of the neck.”