The clavicle, commonly known as the collarbone, is a pair of slender bones found at the base of the neck, with one on each side of the body. Its primary role is to connect the arm to the main body structure. Each collarbone helps keep the shoulder blade in its proper position, facilitating movement.
External Appearance
The collarbone is often easily seen and felt, particularly in individuals with less body fat. It presents as a long, horizontal bone that stretches across the top of the chest, connecting the center of the chest to the shoulder. This bone has a distinctive S-shape, curving forward near the breastbone and then backward toward the shoulder.
You can locate your collarbone by gently touching the area at the base of your neck, just above your chest, and following this bony ridge outwards towards your shoulder. The prominence of the collarbone can vary, with some individuals exhibiting a more noticeable outline under the skin.
Anatomical Structure
Each collarbone is classified as a long bone. It serves as a link within the shoulder girdle, providing the only direct bony connection between the arm and the axial skeleton. The clavicle connects medially, or towards the center of the body, to the manubrium, which is the upper part of the sternum (breastbone).
Laterally, or away from the center, it articulates with the acromion, a bony projection of the scapula (shoulder blade). This dual connection allows the clavicle to act as a strut, holding the shoulder away from the body to provide a wide range of motion for the arm. The clavicle also offers protection to underlying nerves and blood vessels that pass through this region.
Normal Variations and Common Concerns
The appearance of collarbones can differ significantly among individuals due to various factors. Body fat percentage plays a role, as a lower percentage can make the collarbones more visible or prominent. Muscle development in the shoulder and chest areas, along with genetic predispositions, can also influence how defined the collarbones appear. Posture also contributes, as rounded shoulders or slouching can alter the alignment and perceived prominence of the collarbones.
It is common to observe minor asymmetries between the left and right collarbones, such as one appearing slightly more prominent or positioned differently. These variations are part of normal human anatomy and do not indicate a problem. However, sudden changes in appearance, such as new swelling, tenderness, significant deformity, or persistent pain, especially after an injury, should prompt medical attention. These symptoms could signal a fracture or another condition that requires professional evaluation.