What Are Common Ways to Break Your Arm?

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According to Prevention magazine, most upper arm fractures are caused by a direct blow to the humerus, or upper arm bone, such as during a high-impact fall or car accident. The humerus can also break from being severely twisted or from a fall onto an outstretched arm. Fractures to the radius or ulna, the forearm bones, also occur from a direct blow or from falling onto a straight arm.