A device that supports hand function may significantly improve the quality of life of patients with muscular weakness. Since tight constraints such as size and weight are placed upon the device, complexity of the hardware and functional performance should be carefully balanced. A novel force transmission mechanism based on tape springs is presented for use in a hand orthosis. The actuator force is transmitted to the finger by a system consisting of a tape spring, two slider blocks and an end stop per finger. The tape spring allows for bending in one direction, and resists bending in the other direction. A prototype with the new mechanism is constructed. The low profile together with the ability to transmit large forces makes this mechanism suitable for hand orthoses.