
Trigger finger is a condition where the flexor tendon that bends the digit becomes impinged as it glides under a pulley. The flexor tendons are held against the bones by a pulley system, and glide underneath those pulleys. When the flexor tendons begin to catch on a pulley, commonly the first annular pulley, there is a clicking or triggering as the finger straightens out. As the condition progresses, straightening the finger becomes more difficult and can be associated with pain, and eventually an inability to straighten the digit.