<Li> Possible nausea, dizziness, and / or spotty vision due to extreme pain </Li> <P> Clavicle fractures are commonly known as a breaking of the collarbone, and they are usually a result of injury or trauma . The most common type of fracture occurs when a person falls horizontally on the shoulder or with an outstretched hand . A direct hit to the collarbone can also cause a break . In most cases, the direct hit occurs from the lateral side towards the medial side of the bone . The muscles involved in clavicle fractures include the deltoid, trapezius, subclavius, sternocleidomastoid, sternohyoid, and pectoralis major muscles . The ligaments involved include the conoid ligament and trapezoid ligament . Incidents that may lead to a clavicle fracture include automobile accidents, biking accidents (especially common in mountain biking), horizontal falls on the shoulder joint, or contact sports such as football, rugby, hurling, or wrestling . </P> <P> It is most often fractured in the middle third of its length which is its weakest point . The lateral fragment is depressed by the weight of the arm and is pulled medially and forward by the strong adductor muscles of the shoulder joint, especially the pectoralis major . The part of the clavicle near the center of the body is tilted upwards by the sternocleidomastoid muscle . Children and infants are particularly prone to it . Newborns often present clavicle fractures following a difficult delivery . </P> <P> After fracture of the clavicle, the sternocleidomastoid muscle elevates the medial fragment of the bone . The trapezius muscle is unable to hold up the distal fragment owing to the weight of the upper limb, thus the shoulder droops . The adductor muscles of the arm, such as the pectoralis major, may pull the distal fragment medially, causing the bone fragments to override . </P>

Why is the clavicle at risk to fracture when a person falls on shoulder
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