<prompt> Mallet finger is due to -Avulsion of extensor tendon from base of distal phalynxAvulsion of flexor tendon from base of distal phalynxAvulsion of extensor tendon from base of proximal phalynxAvulsion of flexor tendon from base of proximal phalynx  <response>: Ans. is a i.e., Avulsion of extensor tendon from base of distal phalynx Mallet finger Base ball finger Sudden passive flexion of the distal interphalangeal joint as by a ball striking the tip of the finger may rupture the extensor tendon at the point of its insertion into the base of distal phalanx. Sometimes, a fragment of bone is avulsed from the phalanx. Clinically, distal phalanx is in slight flexion and patient is unable to extend DIP joint fully. Treatment is by immobilizing the DIP joint in hyperextension with the help of an aluminium splint finger extension splint or plaster cast. 