A Jersey finger is an injury to an FDP tendon at its point of attachment to the distal phalanx.

This injury often occurs in American football when a player grabs another player’s jersey with the tips of one or more fingers while that player is pulling or running away.[1] The force of this action hyperextends the tip of the finger at the DIP joint while the proximal portion of the finger is flexed. This action can partially or completely rupture the FDP tendon at or near its attachment point on the distal phalanx. Sometimes, the force is great enough to pull off or avulse a piece of phalangeal bone to which the tendon can remain attached.[2] The torn FDP tendon can retract slightly, remaining in the finger near the PIP joint, or can retract more fully into the palm of the hand. A person who suffers a jersey finger injury in which the FDP tendon is completely ruptured cannot flex the affected digit at the DIP joint without assistance.

Symptoms include:

• A pop or rip felt in the finger at the time of the injury
• Pain when moving the injured finger and the inability to bend the last joint
• Tenderness, swelling and warmth of the injured finger
• Bruising after 48 hours
• Occasionally a lump felt in the palm of the finger[3]