Biceps tendonitis is a common cause of shoulder pain, often developing when excessive, abnormal forces are applied across the tendon, including tension (a pulling of the muscle and tendon), compression (pushing or pinching), or shearing (rubbing). When the tendon is subjected to repetitive stresses, it can become irritated, swollen, and painful. Biceps tendinitis develops over time, with pain located at the front of the shoulder, and usually worsens with continued activity. People who perform activities requiring repetitive overhead movement of the arms are more likely to have biceps tendonitis. Pain, tenderness and weakness in the shoulder, especially after activity are common symptoms experienced with biceps tendonitis. This can make daily activities especially hard.