Which of the following is TRUE about trigger finger?

Stenosing flexor tenosynovitis or trigger thumb or trigger finger is characterized by local tenderness over the proximal tendon pulley at the MP joint, with pain referred to the PIP joint and a snapping when the finger or thumb goes through an active range of motion. Usually a history of repetitive strain is involved. Ref: Ewen B, Ha R.G. (2011). Chapter 29. Hand Trauma. In Stone C, Humphries R.L. (Eds), CURRENT Diagnosis & Treatment Emergency Medicine, 7e.