What are tendons?
The tendons in your fingers are like ropes that attach to the ends of your fingers. When your forearm muscle contracts, the tendons pull the fingers into a fist. The tendons run part of their course through a sheath called the flexor tendon sheath. In patients who have a trigger finger, this mechanism of movement is not smooth.
What causes trigger finger to happen?
The cause of trigger finger is unclear, and can seemingly appear from nowhere. It can occur in one or more fingers, and can occur at different times in different locations. Trigger finger results from a discrepancy between the size of the tendon and the entrance to the tendon sheath. This discrepancy can be the result of localized inflammation or a nodular swelling on the tendon itself.
When the size discrepancy between the tendon and the tendon sheath reaches a critical point, the tendon will experience resistance from the tendon sheath. At first, this is experienced as a snapping of the trigger finger when relaxing a fist. If the condition worsens, the trigger finger may need active force from other fingers to straighten, or may not straighten at all.
Why is it called a trigger finger?
The name trigger finger is from the symptom of triggering or snapping. This occurs when relaxing a fist, the affected trigger finger remains flexed. When enough force has been gathered, the trigger finger will suddenly extend, like pulling a trigger.
Read on for more information about the treatment of a trigger finger...
