Mallet Vs Jersey finger December 29, 2018 PRITHWIRAJ MAITI Leave a comment 5 (3) Mallet finger: Inability to extend the distal phalanx Extensor tendon disruption. Jersey finger: Inability to flex the distal phalanx Flexor (FDP) tendon avulsion. How useful was this post? Click on a star to rate it! Submit Rating Average rating 5 / 5. Vote count: 3 No votes so far! Be the first to rate this post. Please leave this field empty Check your inbox or spam folder to confirm your subscription.