Trigger finger (stenosing tenosynovitis):

Trigger finger is a condition that primarily affects the ring finger and the thumb that results in the finger being locked into a bent/flexed position. At times the finger can be moved with difficulty and a popping sound can be heard as it is straightened. Trigger finger is caused by swelling at a specific point on one of the tendons in the hand, specifically the metacarpals and phalanges that prevent the finger from transitioning smoothly back and forth between relaxed and flexed positions. It generally affects two groups of people, infants from 1 – 4 or adults from 40 – 60 (usually work as farmers, musicians, industrial workers etc.). 

Symptoms:

• Inability to fully straighten a finger
• pain/discomfort when flexing and relaxing fingers
• Worse after extended periods of inactivity
• Swelling at the base of a finger

Causes:

• In youth they were born with an abnormality or nodule on their flexor tendon 
• In adults it occurs after excessive or repeated movement of the fingers/hand