The finger may lock or trigger suddenly following attempt to make a fist and then extend with a "snap". Trigger finger occurs most commonly in middle aged femails. It also is reported to be more common in those with Rheumatoid Arthritis, Diabetes, Dupuytrens Contracture and repetive trauma. Trigger finger commonly co-esists with Carpal Tunnel Syndrome. (link to page)
Triggering of the finger or thumb develops when the tendon that bends the finger is unable to glide freely because of a nodule or swelling, this causes the tendon to catch on the pulley at the base of the finger in the palm.
Treatment of this condition is directed at restoring normal tendon gliding. If the triggering symptoms have been present for less than 6 months approximately successful treatment can be achieved by Hand Therapy. A custom thermoplastic splint to rest the tendon and prescribe tendon gliding exercises.