Most of the time, it originates from a recurring motion or forceful use of the finger or thumb. Tendons are fibrous cords that attach muscle to bone. Every single tendon is surrounded by a protective sheath.  麻木和刺痛： 受损神经所支配的区域失去感觉，常伴有刺痛或“针刺”感。 部分肌腱撕裂可使用夹板或支架固定，以防止进一步拉伤，并使受伤的组织自然愈合。这些装置可固定受影响的区域，促进康复... https://www.theorthopaedicandpainpractice.com/why-cant-i-straighten-the-tip-of-my-finger/