Mallet Finger (Jamming a Finger)

The extensor tendons, which are located on the back of the hand, allow individuals to straighten the thumb and fingers. These tendons originate from the muscles in the forearm. The tendons become thin and flat as they continue on into the fingers of the hand. It is these small tendons that allow for coordination and delicate finger motions.

Extensor tendons are located just beneath the top surface of the skin, directly on the bone, and on the back of the fingers and hands. Due to their location, these tendons are often injured. Even the common trauma of jamming a finger could cause these thin tendons to rip away from their attachment to the bone. After an injury of this type, it may prove difficult to straighten one or more of the finger joints. Treatment is required to help return the tendon to normal functionality.

Causes

​A mallet finger is caused when the extensor tendon which helps to extend the knuckle of the finger closest to the tip of the finger is pulled off the bone. is damaged. When an object such as a ball strikes the tip of the finger or thumb, the force of the blow damages the thin tendon required to straighten the finger. This type of injury is often referred to as a “baseball finger.” The injured finger may droop noticeably and is usually swollen, bruised, and very painful.