Many PIP joint injuries which appear to be innocuous are actually very severe injuries to this small hinged joint and carry a high percentage of disability for the hand as well as the individual digit. A flexion contracture of the PIP joint of one digit may significantly reduce the functional capacity of the entire hand. To prevent such physical impairment, the type of PIP joint injury must be defined and the proper treatment for the particular injury must be initiated. Second, it is paramount that prolonged immobilization of this joint be prevented. It has been found, through clinical experience and experimental projects, that the early healing process is complete by 3 weeks and active motion may then be initiated without any detrimental effects. Extensor and flexor contractures of this joint are apt to occur in digits which have been immobilized for significantly longer than 3 weeks. Finally, the well-publicized "position of function" for the hand is not necessarily the ideal position for the rehabilitation of the hand. The "intrinsic plus position" is the position of choice for immobilization of the MP and PIP joints to prevent contractures. This concept has been confirmed by our clinical experience and the biomechanical studies performed in the laboratory.