de Quervain's Tenosynovitis
Patients with de Quervain's Tenosynovitis have painful tendons on the thumb side of the wrist. Tendons are the ropes that the muscle uses to pull the bone. You can see them on the back of your hand when you straighten your fingers. In de Quervain's Tenosynovitis, the tunnel (the first extensor compartment; see Figure 1A-B) where the tendons run narrows due to the thickening of the soft tissues that make up the tunnel. Hand and thumb motion cause pain, especially with forceful grasping or twisting.