Anatomy 101: The Extensor Tendon


Tendons are cord-like extensions that connect muscles to bones. Extensor tendons are thin tendons located on the back of the hand, just under the skin. These particular tendons allow you to straighten your fingers and thumb and can be injured by a simple cut or jammed finger. These injuries can cause the tendons to rip from their attachment to the bone, making it hard to straighten your fingers or thumb as you usually do.

Here are two common conditions that result from an injured extensor tendon:

  1. Mallet Fingers are common in baseball players and are typically caused when a ball hits the tip of the finger or thumb. It causes the finger or thumb to droop at the tip.
  2. Boutonnière Deformities are when the middle part of the finger is bent downward.

If you injure your extensor tendon(s), there are a few different options for treatment, depending on the severity. If your tendon is injured by a jammed finger, for example, the most likely treatment is a splint, which will be worn at all times until the tendon is healed (8-12 weeks). The splint keeps the tendon in place so that it can heal. If you’ve cut yourself and the tendon itself was cut, you may need stitches. You may even need surgery to place a pin through the bone, working as an internal splint.

After your injury, you may also need hand therapy to regain motion in the hand. Visit a hand surgeon to discuss the best treatment options for you.

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