Biceps Tendon Rupture/Tear: Injuries to the distal biceps tendon can be partial or complete ruptures. They commonly occur in the dominant arm of middle aged adults. Unanticipated loading of the tendon is a common mechanism of injury when the biceps muscle is contracting but the elbow is rapidly straightened, such as when a heavy object is attempted to be caught when it unexpectantly falls from a height. Typically, the injured tendon has some level of preexisting disease or degeneration, called tendonosis, that makes it vulnerable to injury. Persons who smoke and those who are not physically active are more likely to rupture their biceps tendon when it is subjected to heavy loads.