The clavicle, commonly known as the collarbone, is a long, slender bone located horizontally at the base of the neck. It serves as a connection between the torso and the arms, with one clavicle found on each side of the body.
Anatomical Structure and Position
The clavicle is a uniquely shaped bone, often described as an S-shape. This distinct curvature is important for its mechanical function. The clavicle is situated horizontally across the upper part of the ribcage, extending from the sternum in the center of the chest to the scapula, located laterally.
The clavicle forms two significant joints: the sternoclavicular joint, where it connects with the sternum, and the acromioclavicular joint, where it articulates with the acromion process of the scapula. These connections are stabilized by ligaments. The clavicle is distinct as it is the only long bone that lies horizontally and provides the sole direct bony attachment between the arm and the axial skeleton.
Essential Functions
The clavicle plays several roles, primarily supporting the shoulder and arm. It acts as a rigid support from which the scapula and the arm are suspended, helping to keep the upper limb positioned away from the body. This arrangement is important for allowing a wide range of motion for the upper limb, including movements like reaching, lifting, and throwing.
The clavicle also functions as a strut, enabling the shoulder blade to move freely and transferring physical forces from the arm to the axial skeleton. Additionally, it provides a protective shield for underlying nerves and blood vessels that pass from the neck into the arm.
Common Conditions and Importance
Given its exposed position and relatively slender structure, the clavicle is one of the most frequently fractured bones in the body. These fractures commonly result from direct impacts to the shoulder, such as falls onto the shoulder or an outstretched arm, or from car accidents and sports injuries. In some cases, a clavicle fracture can even occur in infants during birth.
Symptoms of a broken collarbone include pain, swelling, tenderness, and a possible bump or deformity over the break. Such an injury can significantly affect mobility, making it difficult to lift the arm and potentially causing the shoulder to sag. While many clavicle fractures can heal with non-surgical treatment like slings and rest, severe cases or those with significant displacement may require surgical intervention. The integrity of the clavicle is important for maintaining overall upper body function and stability, and successful healing typically restores full range of motion and strength.