Your finger likely got stuck bent due to a condition called trigger finger. This happens because a tendon in your finger or thumb has become irritated and swollen, preventing it from moving smoothly within its protective sheath.
When the tendon swells, it can't glide easily through the narrow tunnel (the sheath) that holds it in place. As a result, the tendon gets caught, causing your finger or thumb to become stuck or "locked" in a bent or straight position.
According to information published around November 2022, each tendon is wrapped in a sheath that holds it in place. The tendon sometimes can become irritated and swell, preventing it from sliding smoothly under the sheath. When that happens, your finger or thumb can get stuck in a bent or straight position in a condition called trigger finger.
Here's a breakdown of why this sticking occurs:
- Tendons: These are cord-like tissues that connect muscles to bones, allowing you to bend and straighten your fingers.
- Tendon Sheath: A tunnel-like structure that surrounds the tendon, helping it slide smoothly and stay in place.
- Irritation and Swelling: When the tendon or its sheath becomes inflamed (irritated and swollen), often from repetitive motion or underlying health conditions, the space inside the sheath narrows.
- Getting Stuck: The swollen tendon can no longer glide freely through the narrowed sheath. It might catch at the entrance of the sheath, causing the finger to lock when you try to straighten it, or prevent it from bending fully. You might feel a click or pop as the tendon forces its way through.
Understanding Trigger Finger
Trigger finger (also known as stenosing tenosynovitis) can affect any finger or the thumb. It's a common condition that can make simple tasks difficult.
| Component | Role | Issue in Trigger Finger |
|---|---|---|
| Tendon | Connects muscle to bone; enables movement | Becomes irritated and swells |
| Tendon Sheath | Holds tendon in place; allows smooth glide | Inflamed/constricted, narrowing the passage |
This catching or sticking is the defining characteristic of the condition and directly explains why your finger felt stuck in a bent position.
