Injuries to the distal biceps tendon are not uncommon. Most often occurring in middle-aged men, these injuries often occur when lifting heavy objects. Over 90 percent of distal biceps tendon tears occur in men. They are much more common in the dominant arm with over 80 percent of injuries occurring on the dominant side. While the perception is that these injuries are often associated with athletic activities or very high demand work activities, the reality is that most often they occur unexpectedly during a seemingly normal lifting activity.
Source: Verywell Health