Abstract: Device permitting the control of the flexion of a defective limb of a handicapped person which is fitted with an orthopaedic appliance consisting of two rigid members (21,22) connected together by a pivot pin (26).This device (20), situated on and as an extension of the pivot pin (26), comprises a freewheel system (12) on which a hub (10) is mounted by a force fit. A braking system composed of two articulated jaws (4,6) surrounds the hub (10).