Usually, it emanates from a recurring motion or forceful use of your respective finger or thumb. Tendons are fibrous cords that connect muscle to bone. Just about every tendon is surrounded by a protecting sheath.  Even though normally pain-free, they could cause discomfort or interfere with joint movement. De Quervain's https://www.theorthopaedicandpainpractice.com/why-cant-i-straighten-the-tip-of-my-finger/