Introduction: The predynamic (partial) and dynamic (total) injury of the scapholunate ligamentous complex conditions the normal kinetics and kinematics of the carpal bone in the performance of everyday activities. Considering this, we have designed an exerciser that allows the active flex extension of the wrist to work in a specific progressive and global way in the sagittal plane within the permanent adaptation sector I (up to 20°) and the usual movement sector II (up to 40°) of N. Kuhlmann. Materials and Methods: The instrument has been designed in rigid plastic with the support and subjection of the forearm and mobile distal handle, which moves within a mechanical blocked guide that allows the movement of the wrist flex extension in N. Kuhlmann I and II sectors. It is also possible to apply resistance in the movement according to the rehabilitation criteria. Outcome: The design of an exerciser that allows the active flex extension of the wrist has been accomplished for the treatment of the scapholunate ligamentous complex injury. Conclusions: The application of the exposed exerciser for the rehabilitation of the scapholunate instability restricts the joint excursion to a protected rank, avoiding the exposure to ligamentous or muscular tensions that may aggravate the pathology.
