Trigger finger is a type of tendinitis which develops in the tendons which bend the fingers.
It is a common problem because of the way that the hand is made, which may be a little different than you would suspect. There are no muscles in the fingers themselves. We actually move our fingers by remote control. Muscles in the forearm are connected to the finger bones by smooth, flexible strings, called tendons. The muscles pull on the tendons, which then bend the finger joints.