Trigger finger is a condition where there is a size disparity between the flexor tendons and the surrounding pulley system at the first annular pulley (the A1 pulley). This causes the tendon to catch on the pulley as it attempts to glide through unless enough pressure is developed to allow it to forcefully move through the pulley. The exact cause of trigger finger is not always clear, but it is often attributed to overuse injuries or repetitive motions.

Flexor Digitorum Profundus (FDP) is a muscle that extends from our elbows, down our forearms, and attaches to the bones of our fingers via its tendons. The FDP muscle is involved in finger flexion (bending/curling our fingers) making it an extremely important muscle for climbing. Our FDP muscles are involved with a variety of climbing grips (crimps, pinches, slopers, jugs, etc.), and developing FDP strength is essential for climbing performance, but it is also one of the most common sources of hand, finger, or forearm pain and injury in climbers.