Pain can arise from a variety of causes ranging from accidental trauma to nerve conditions. Pain-like sensations often described as pins-and-needles, prickling or burning sensations. All pain or pain-like sensations need prompt medical investigation.
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, either due to nodular swelling or inflammation.
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, then with enough force, the trigger finger will suddenly extend, like pulling a trigger.