Thumb tendons are strong, cord-like tissues that connect muscles in your forearm to the bones in your thumb, enabling movement.
Tendons play a crucial role in the movement of your hands and fingers, including your thumb. According to information from April 13, 2023, there are two main groups of tendons in the hand that facilitate these movements:
Types of Thumb Tendons
Like fingers, the thumb relies on these two types of tendons for its range of motion:
-
Extensor Tendons:
- Location: These tendons run from the forearm, across the back of your hand to your fingers and thumb.
- Function: They allow you to straighten your fingers and thumb. When the muscles connected to these tendons contract, they pull on the bones of the thumb to extend it backward or straighten it from a bent position.
-
Flexor Tendons:
- Location: These tendons run from your forearm, through your wrist and across the palm of your hand. While the reference specifically mentions "to your fingers," flexor tendons also extend to the thumb, allowing for bending motions.
- Function: They allow you to bend your fingers and thumb. When the corresponding muscles contract, the flexor tendons pull on the thumb bones to curl it towards the palm.
Both extensor and flexor tendons are essential for the complex movements the thumb performs, such as grasping, pinching, and opposition (touching the other fingers).
Tendon Function Summary
Here's a simple breakdown of the two main tendon types relevant to thumb movement:
| Tendon Type | Location (as per reference) | Primary Function (as per reference) | Thumb Movement |
|---|---|---|---|
| Extensor | From forearm, across back of hand to fingers/thumb | Straighten fingers/thumb | Straightening the thumb |
| Flexor | From forearm, through wrist, across palm | Bend fingers | Bending/curling the thumb |
Healthy thumb tendons are smooth and glide easily within sheaths (tunnels) that protect them. Issues like inflammation or injury can affect their ability to move freely, causing pain and limiting thumb function.
