A repetitive and prolonged use of the shoulder and upper arm may fray the biceps tendons. This leads to the development of tendon inflammation or tendonitis, followed by an initial partial tear, possibly leading to a complete rupture of the tendon when executing a sudden and strenuous movement. A tendon rupture severely impairs the use of the arm. The causes leading to a biceps tendon rupture are:
Tear of the rotator cuff
Shoulder instability
Joint stiffness particularly of the elbow
Lack of, or excessive training
Inadequate warm up
Weakness of the muscles
Tightness of the biceps