More often than not, it comes from a repeated motion or forceful use within your finger or thumb. Tendons are fibrous cords that connect muscle to bone. Just about every tendon is surrounded by a protective sheath.  Splinting is the first-line treatment for just a mallet finger. The goal is https://www.theorthopaedicandpainpractice.com/why-cant-i-straighten-the-tip-of-my-finger/