Trigger Finger is an inflammation of the tendon(s) that flex or bend the finger(s). The flexor tendons travel through the palm and into the fingers. The tendons act as cords that pull the fingers down into a fist and then relax as the extensor tendons on the back of the hand straighten the fingers. As they travel through the palm, they glide through a thin sheath of material lined with lubricating synovium that aids in smooth movement. The tendons pass through a series of pulleys that hold the tendons close to the finger. Anything that reduces space inside the tendon sheath or that compresses the space it moves through, can cause the tendon to get stuck as it goes through the pulley.
Think of the tendon as a line on a fishing rod and the pulleys as the eyelets that keep the line in contact with the rod as it bends and straightens. A knot in the line may make the line catch as it is pulled through the eyelet. If the knot keeps getting larger or the pulley gets tighter, eventually it will be too large to slide back in the other direction and the line will be stuck. That is what happens to the tendons. They simple get too large to move back and forth through the pulleys.
The most common symptom of Trigger Finger is a clicking or locking of the fingers when attempting to straighten them from a fisted position. Typically a finger will get stuck with the big knuckle and middle knuckle in a bent position. In severe cases, the finger needs to be passively straightened by using the other hand. Triggering is frequently experienced at night or in the morning after sleeping with the hand in a fisted position for a long period. There may be tenderness when pressure is applied over the base of the finger on the palm side of the hand.
Oval-8 Finger Splints help reduce triggering by limiting finger flexion. By limiting finger motion, the tendon is less likely to get caught in the pulley and it has the chance to rest and heal. Oval-8 splints can be worn during the day and at night. They are ideal to use after the finger has been injected with an anti-inflammatory medication. The splint allows the finger to rest and the injection to be fully effective.