The biceps muscle is in the front of your upper arm. It helps you bend your elbow and rotate your arm. It also helps keep your shoulder stable.
Tendons attach muscles to bones. Your biceps tendons attach the biceps muscle to bones in the shoulder and in the elbow. If you tear the biceps tendon at the shoulder, you may lose some strength in your arm and be unable to forcefully turn your arm from palm down to palm up.
Many people can still function with a biceps tendon tear, and only need simple treatments to relieve symptoms. Some people require surgery to repair the torn tendon.
Biceps tendon tears can be either partial or complete.
A complete tear of the long head at its attachment point in the glenoid.
Partial tears. Many tears do not completely sever the tendon.
Complete tears. A complete tear will split the tendon into two pieces.
In many cases, torn tendons begin by fraying. As the damage progresses, the tendon can completely tear, sometimes with lifting a heavy object.
The long head of the biceps tendon is more likely to be injured. This is because it is vulnerable as it travels through the shoulder joint to its attachment point in the socket. Fortunately, the biceps has two attachments at the shoulder. The short head of the biceps rarely tears. Because of this second attachment, many people can still use their biceps even after a complete tear of the long head.
When you tear your biceps tendon, you can also damage other parts of your shoulder, such as the rotator cuff tendons.