Abstract: A spring metacarpophalangeal flexion splint designed for dynamically flexing the metacarpophalangeal joints without restricting normal hand use includes: a proximal phalangeal piece which is adapted to contact and cover the proximal phalanges of the hand and is formed of a resilient metal strip which is substantially covered with a pliant cushioning material; a palm piece adapted to fit into the palmar arch and crease of the hand and is made up of a rigid tube covered with a pliant cushioning material; and a pair of spaced apart generally parallel spring wires. The spring wires are disposed laterally with respect to the hand and connect the proximal phalangeal piece with the palm piece. A loop extension of the spring wires from the palm piece provides a means of attachment for a dorsal strap which is extended between the wires to permit the increase and decrease of tension on the proximal phalangeal splint upon the respective tightening and loosening of the strap.